| Message ID | 20220216131332.1489939-19-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | clean up asm/uaccess.h, kill set_fs for good | expand |
Hi Arnd, Fix spelling in $subject... sparc/Kconfig b/arch/sparc/Kconfig > index 9f6f9bce5292..9276f321b3e3 100644 > --- a/arch/sparc/Kconfig > +++ b/arch/sparc/Kconfig > @@ -46,7 +46,6 @@ config SPARC > select LOCKDEP_SMALL if LOCKDEP > select NEED_DMA_MAP_STATE > select NEED_SG_DMA_LENGTH > - select SET_FS > select TRACE_IRQFLAGS_SUPPORT > > config SPARC32 > @@ -101,6 +100,7 @@ config SPARC64 > select HAVE_SETUP_PER_CPU_AREA > select NEED_PER_CPU_EMBED_FIRST_CHUNK > select NEED_PER_CPU_PAGE_FIRST_CHUNK > + select SET_FS This looks wrong - looks like some merge went wrong here. > > config ARCH_PROC_KCORE_TEXT > def_bool y > diff --git a/arch/sparc/include/asm/processor_32.h b/arch/sparc/include/asm/processor_32.h > index 647bf0ac7beb..b26c35336b51 100644 > --- a/arch/sparc/include/asm/processor_32.h > +++ b/arch/sparc/include/asm/processor_32.h > @@ -32,10 +32,6 @@ struct fpq { > }; > #endif > > -typedef struct { > - int seg; > -} mm_segment_t; > - > /* The Sparc processor specific thread struct. */ > struct thread_struct { > struct pt_regs *kregs; > @@ -50,11 +46,9 @@ struct thread_struct { > unsigned long fsr; > unsigned long fpqdepth; > struct fpq fpqueue[16]; > - mm_segment_t current_ds; > }; > > #define INIT_THREAD { \ > - .current_ds = KERNEL_DS, \ > .kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \ > } > > diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h > index 367747116260..9fd6c53644b6 100644 > --- a/arch/sparc/include/asm/uaccess_32.h > +++ b/arch/sparc/include/asm/uaccess_32.h > @@ -12,19 +12,6 @@ > #include <linux/string.h> > > #include <asm/processor.h> > - > -/* Sparc is not segmented, however we need to be able to fool access_ok() > - * when doing system calls from kernel mode legitimately. > - * > - * "For historical reasons, these macros are grossly misnamed." -Linus > - */ > - > -#define KERNEL_DS ((mm_segment_t) { 0 }) > -#define USER_DS ((mm_segment_t) { -1 }) > - > -#define get_fs() (current->thread.current_ds) > -#define set_fs(val) ((current->thread.current_ds) = (val)) > - > #include <asm-generic/access_ok.h> > > /* Uh, these should become the main single-value transfer routines.. > diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c > index 2dc0bf9fe62e..88c0c14aaff0 100644 > --- a/arch/sparc/kernel/process_32.c > +++ b/arch/sparc/kernel/process_32.c > @@ -300,7 +300,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, > extern int nwindows; > unsigned long psr; > memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); > - p->thread.current_ds = KERNEL_DS; > ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); > childregs->u_regs[UREG_G1] = sp; /* function */ > childregs->u_regs[UREG_G2] = arg; > @@ -311,7 +310,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, > } > memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); > childregs->u_regs[UREG_FP] = sp; > - p->thread.current_ds = USER_DS; > ti->kpc = (((unsigned long) ret_from_fork) - 0x8); > ti->kpsr = current->thread.fork_kpsr | PSR_PIL; > ti->kwim = current->thread.fork_kwim; Other than the above the sparc32 changes looks fine, and with the Kconf stuff fixed: Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes
On Wed, Feb 16, 2022 at 7:44 PM Sam Ravnborg <sam@ravnborg.org> wrote: > > Hi Arnd, > > Fix spelling in $subject... done > sparc/Kconfig b/arch/sparc/Kconfig > > index 9f6f9bce5292..9276f321b3e3 100644 > > --- a/arch/sparc/Kconfig > > +++ b/arch/sparc/Kconfig > > @@ -46,7 +46,6 @@ config SPARC > > select LOCKDEP_SMALL if LOCKDEP > > select NEED_DMA_MAP_STATE > > select NEED_SG_DMA_LENGTH > > - select SET_FS > > select TRACE_IRQFLAGS_SUPPORT > > > > config SPARC32 > > @@ -101,6 +100,7 @@ config SPARC64 > > select HAVE_SETUP_PER_CPU_AREA > > select NEED_PER_CPU_EMBED_FIRST_CHUNK > > select NEED_PER_CPU_PAGE_FIRST_CHUNK > > + select SET_FS > This looks wrong - looks like some merge went wrong here. Fixed now. > > Other than the above the sparc32 changes looks fine, and with the Kconf > stuff fixed: > Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes Thanks! Arnd
Arnd Bergmann <arnd@kernel.org> writes: > From: Arnd Bergmann <arnd@arndb.de> > > There are no remaining callers of set_fs(), so CONFIG_SET_FS > can be removed globally, along with the thread_info field and > any references to it. > > This turns access_ok() into a cheaper check against TASK_SIZE_MAX. > > With CONFIG_SET_FS gone, so drop all remaining references to > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). For the bits I have looked at recently, and think I understand. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > fs/exec.c | 6 -- > kernel/exit.c | 14 ----- > kernel/kthread.c | 5 -- > > diff --git a/fs/exec.c b/fs/exec.c > index 79f2c9483302..bc68a0c089ac 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1303,12 +1303,6 @@ int begin_new_exec(struct linux_binprm * bprm) > if (retval) > goto out_unlock; > > - /* > - * Ensure that the uaccess routines can actually operate on userspace > - * pointers: > - */ > - force_uaccess_begin(); > - > if (me->flags & PF_KTHREAD) > free_kthread_struct(me); > me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | > diff --git a/kernel/exit.c b/kernel/exit.c > index b00a25bb4ab9..0884a75bc2f8 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -737,20 +737,6 @@ void __noreturn do_exit(long code) > > WARN_ON(blk_needs_flush_plug(tsk)); > > - /* > - * If do_dead is called because this processes oopsed, it's possible > - * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before > - * continuing. Amongst other possible reasons, this is to prevent > - * mm_release()->clear_child_tid() from writing to a user-controlled > - * kernel address. > - * > - * On uptodate architectures force_uaccess_begin is a noop. On > - * architectures that still have set_fs/get_fs in addition to handling > - * oopses handles kernel threads that run as set_fs(KERNEL_DS) by > - * default. > - */ > - force_uaccess_begin(); > - > kcov_task_exit(tsk); > > coredump_task_exit(tsk); > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 38c6dd822da8..16c2275d4b50 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -55,7 +55,6 @@ struct kthread { > int result; > int (*threadfn)(void *); > void *data; > - mm_segment_t oldfs; > struct completion parked; > struct completion exited; > #ifdef CONFIG_BLK_CGROUP > @@ -1441,8 +1440,6 @@ void kthread_use_mm(struct mm_struct *mm) > mmdrop(active_mm); > else > smp_mb(); > - > - to_kthread(tsk)->oldfs = force_uaccess_begin(); > } > EXPORT_SYMBOL_GPL(kthread_use_mm); > > @@ -1457,8 +1454,6 @@ void kthread_unuse_mm(struct mm_struct *mm) > WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); > WARN_ON_ONCE(!tsk->mm); > > - force_uaccess_end(to_kthread(tsk)->oldfs); > - > task_lock(tsk); > /* > * When a kthread stops operating on an address space, the loop
s/maining/remaining/ ? Or maybe rather: uaccess: remove CONFIG_SET_FS because it is all gone now. > With CONFIG_SET_FS gone, so drop all remaining references to > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). And this sentence does not parse.
On Fri, Feb 18, 2022 at 7:37 AM Christoph Hellwig <hch@lst.de> wrote: > > s/maining/remaining/ ? > > Or maybe rather: > > uaccess: remove CONFIG_SET_FS > > because it is all gone now. > > > With CONFIG_SET_FS gone, so drop all remaining references to > > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). > > And this sentence does not parse. Both fixed now, thanks! Arnd
Hi Arnd, > From: Arnd Bergmann <arnd@arndb.de> > > There are no remaining callers of set_fs(), so CONFIG_SET_FS > can be removed globally, along with the thread_info field and > any references to it. > > This turns access_ok() into a cheaper check against TASK_SIZE_MAX. > > With CONFIG_SET_FS gone, so drop all remaining references to > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes Regards, Sergey
On Wed, Feb 16, 2022 at 02:13:32PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > There are no remaining callers of set_fs(), so CONFIG_SET_FS > can be removed globally, along with the thread_info field and > any references to it. > > This turns access_ok() into a cheaper check against TASK_SIZE_MAX. > > With CONFIG_SET_FS gone, so drop all remaining references to > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- ... > arch/openrisc/Kconfig | 1 - > arch/openrisc/include/asm/thread_info.h | 7 --- > arch/openrisc/include/asm/uaccess.h | 23 -------- ... > fs/exec.c | 6 -- > include/asm-generic/access_ok.h | 10 +--- > include/asm-generic/uaccess.h | 25 +------- > include/linux/syscalls.h | 4 -- > include/linux/uaccess.h | 33 ----------- > include/rdma/ib.h | 2 +- > kernel/events/callchain.c | 4 -- > kernel/events/core.c | 3 - > kernel/exit.c | 14 ----- > kernel/kthread.c | 5 -- > kernel/stacktrace.c | 3 - > kernel/trace/bpf_trace.c | 4 -- > mm/maccess.c | 11 ---- > mm/memory.c | 8 --- > net/bpfilter/bpfilter_kern.c | 2 +- > 72 files changed, 10 insertions(+), 522 deletions(-) > delete mode 100644 arch/arc/include/asm/segment.h > delete mode 100644 arch/csky/include/asm/segment.h > delete mode 100644 arch/h8300/include/asm/segment.h > > diff --git a/arch/Kconfig b/arch/Kconfig > index fa5db36bda67..99349547afed 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -24,9 +24,6 @@ config KEXEC_ELF > config HAVE_IMA_KEXEC > bool > > -config SET_FS > - bool > - > config HOTPLUG_SMT > bool > ... > diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig > index f724b3f1aeed..0d68adf6e02b 100644 > --- a/arch/openrisc/Kconfig > +++ b/arch/openrisc/Kconfig > @@ -36,7 +36,6 @@ config OPENRISC > select ARCH_WANT_FRAME_POINTERS > select GENERIC_IRQ_MULTI_HANDLER > select MMU_GATHER_NO_RANGE if MMU > - select SET_FS > select TRACE_IRQFLAGS_SUPPORT > > config CPU_BIG_ENDIAN > diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h > index 659834ab87fa..4af3049c34c2 100644 > --- a/arch/openrisc/include/asm/thread_info.h > +++ b/arch/openrisc/include/asm/thread_info.h > @@ -40,18 +40,12 @@ > */ > #ifndef __ASSEMBLY__ > > -typedef unsigned long mm_segment_t; > - > struct thread_info { > struct task_struct *task; /* main task structure */ > unsigned long flags; /* low level flags */ > __u32 cpu; /* current CPU */ > __s32 preempt_count; /* 0 => preemptable, <0 => BUG */ > > - mm_segment_t addr_limit; /* thread address space: > - 0-0x7FFFFFFF for user-thead > - 0-0xFFFFFFFF for kernel-thread > - */ > __u8 supervisor_stack[0]; > > /* saved context data */ > @@ -71,7 +65,6 @@ struct thread_info { > .flags = 0, \ > .cpu = 0, \ > .preempt_count = INIT_PREEMPT_COUNT, \ > - .addr_limit = KERNEL_DS, \ > .ksp = 0, \ > } > > diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h > index 8f049ec99b3e..d6500a374e18 100644 > --- a/arch/openrisc/include/asm/uaccess.h > +++ b/arch/openrisc/include/asm/uaccess.h > @@ -22,29 +22,6 @@ > #include <linux/string.h> > #include <asm/page.h> > #include <asm/extable.h> > - > -/* > - * The fs value determines whether argument validity checking should be > - * performed or not. If get_fs() == USER_DS, checking is performed, with > - * get_fs() == KERNEL_DS, checking is bypassed. > - * > - * For historical reasons, these macros are grossly misnamed. > - */ > - > -/* addr_limit is the maximum accessible address for the task. we misuse > - * the KERNEL_DS and USER_DS values to both assign and compare the > - * addr_limit values through the equally misnamed get/set_fs macros. > - * (see above) > - */ > - > -#define KERNEL_DS (~0UL) > - > -#define USER_DS (TASK_SIZE) > -#define get_fs() (current_thread_info()->addr_limit) > -#define set_fs(x) (current_thread_info()->addr_limit = (x)) > - > -#define uaccess_kernel() (get_fs() == KERNEL_DS) > - > #include <asm-generic/access_ok.h> > > /* ... > diff --git a/fs/exec.c b/fs/exec.c > index 79f2c9483302..bc68a0c089ac 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1303,12 +1303,6 @@ int begin_new_exec(struct linux_binprm * bprm) > if (retval) > goto out_unlock; > > - /* > - * Ensure that the uaccess routines can actually operate on userspace > - * pointers: > - */ > - force_uaccess_begin(); > - > if (me->flags & PF_KTHREAD) > free_kthread_struct(me); > me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | > diff --git a/include/asm-generic/access_ok.h b/include/asm-generic/access_ok.h > index 1aad8964d2ed..88a7cb5d9aad 100644 > --- a/include/asm-generic/access_ok.h > +++ b/include/asm-generic/access_ok.h > @@ -16,16 +16,8 @@ > #define TASK_SIZE_MAX TASK_SIZE > #endif > > -#ifndef uaccess_kernel > -#ifdef CONFIG_SET_FS > -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) > -#else > -#define uaccess_kernel() (0) > -#endif > -#endif > - > #ifndef user_addr_max > -#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE_MAX) > +#define user_addr_max() TASK_SIZE_MAX > #endif > > #ifndef __access_ok > diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h > index ebc685dc8d74..a5be9e61a2a2 100644 > --- a/include/asm-generic/uaccess.h > +++ b/include/asm-generic/uaccess.h > @@ -8,6 +8,7 @@ > * address space, e.g. all NOMMU machines. > */ > #include <linux/string.h> > +#include <asm-generic/access_ok.h> > > #ifdef CONFIG_UACCESS_MEMCPY > #include <asm/unaligned.h> > @@ -94,30 +95,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) > #define INLINE_COPY_TO_USER > #endif /* CONFIG_UACCESS_MEMCPY */ > > -#ifdef CONFIG_SET_FS > -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) > - > -#ifndef KERNEL_DS > -#define KERNEL_DS MAKE_MM_SEG(~0UL) > -#endif > - > -#ifndef USER_DS > -#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) > -#endif > - > -#ifndef get_fs > -#define get_fs() (current_thread_info()->addr_limit) > - > -static inline void set_fs(mm_segment_t fs) > -{ > - current_thread_info()->addr_limit = fs; > -} > -#endif > - > -#endif /* CONFIG_SET_FS */ > - > -#include <asm-generic/access_ok.h> > - > /* > * These are the main single-value transfer routines. They automatically > * use the right size if we just have the right pointer type. > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > index 819c0cb00b6d..a34b0f9a9972 100644 > --- a/include/linux/syscalls.h > +++ b/include/linux/syscalls.h > @@ -290,10 +290,6 @@ static inline void addr_limit_user_check(void) > return; > #endif > > - if (CHECK_DATA_CORRUPTION(uaccess_kernel(), > - "Invalid address limit on user-mode return")) > - force_sig(SIGKILL); > - > #ifdef TIF_FSCHECK > clear_thread_flag(TIF_FSCHECK); > #endif > diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h > index 2c31667e62e0..2421a41f3a8e 100644 > --- a/include/linux/uaccess.h > +++ b/include/linux/uaccess.h > @@ -10,39 +10,6 @@ > > #include <asm/uaccess.h> > > -#ifdef CONFIG_SET_FS > -/* > - * Force the uaccess routines to be wired up for actual userspace access, > - * overriding any possible set_fs(KERNEL_DS) still lingering around. Undone > - * using force_uaccess_end below. > - */ > -static inline mm_segment_t force_uaccess_begin(void) > -{ > - mm_segment_t fs = get_fs(); > - > - set_fs(USER_DS); > - return fs; > -} > - > -static inline void force_uaccess_end(mm_segment_t oldfs) > -{ > - set_fs(oldfs); > -} > -#else /* CONFIG_SET_FS */ > -typedef struct { > - /* empty dummy */ > -} mm_segment_t; > - > -static inline mm_segment_t force_uaccess_begin(void) > -{ > - return (mm_segment_t) { }; > -} > - > -static inline void force_uaccess_end(mm_segment_t oldfs) > -{ > -} > -#endif /* CONFIG_SET_FS */ > - > /* > * Architectures should provide two primitives (raw_copy_{to,from}_user()) > * and get rid of their private instances of copy_{to,from}_user() and > diff --git a/include/rdma/ib.h b/include/rdma/ib.h > index 83139b9ce409..f7c185ff7a11 100644 > --- a/include/rdma/ib.h > +++ b/include/rdma/ib.h > @@ -75,7 +75,7 @@ struct sockaddr_ib { > */ > static inline bool ib_safe_file_access(struct file *filp) > { > - return filp->f_cred == current_cred() && !uaccess_kernel(); > + return filp->f_cred == current_cred(); > } > > #endif /* _RDMA_IB_H */ > diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c > index 58cbe357fb2b..1273be84392c 100644 > --- a/kernel/events/callchain.c > +++ b/kernel/events/callchain.c > @@ -209,17 +209,13 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, > } > > if (regs) { > - mm_segment_t fs; > - > if (crosstask) > goto exit_put; > > if (add_mark) > perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); > > - fs = force_uaccess_begin(); > perf_callchain_user(&ctx, regs); > - force_uaccess_end(fs); > } > } > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 57c7197838db..11ca7303d6df 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -6746,7 +6746,6 @@ perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, > unsigned long sp; > unsigned int rem; > u64 dyn_size; > - mm_segment_t fs; > > /* > * We dump: > @@ -6764,9 +6763,7 @@ perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, > > /* Data. */ > sp = perf_user_stack_pointer(regs); > - fs = force_uaccess_begin(); > rem = __output_copy_user(handle, (void *) sp, dump_size); > - force_uaccess_end(fs); > dyn_size = dump_size - rem; > > perf_output_skip(handle, rem); > diff --git a/kernel/exit.c b/kernel/exit.c > index b00a25bb4ab9..0884a75bc2f8 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -737,20 +737,6 @@ void __noreturn do_exit(long code) > > WARN_ON(blk_needs_flush_plug(tsk)); > > - /* > - * If do_dead is called because this processes oopsed, it's possible > - * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before > - * continuing. Amongst other possible reasons, this is to prevent > - * mm_release()->clear_child_tid() from writing to a user-controlled > - * kernel address. > - * > - * On uptodate architectures force_uaccess_begin is a noop. On > - * architectures that still have set_fs/get_fs in addition to handling > - * oopses handles kernel threads that run as set_fs(KERNEL_DS) by > - * default. > - */ > - force_uaccess_begin(); > - > kcov_task_exit(tsk); > > coredump_task_exit(tsk); > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 38c6dd822da8..16c2275d4b50 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -55,7 +55,6 @@ struct kthread { > int result; > int (*threadfn)(void *); > void *data; > - mm_segment_t oldfs; > struct completion parked; > struct completion exited; > #ifdef CONFIG_BLK_CGROUP > @@ -1441,8 +1440,6 @@ void kthread_use_mm(struct mm_struct *mm) > mmdrop(active_mm); > else > smp_mb(); > - > - to_kthread(tsk)->oldfs = force_uaccess_begin(); > } > EXPORT_SYMBOL_GPL(kthread_use_mm); > > @@ -1457,8 +1454,6 @@ void kthread_unuse_mm(struct mm_struct *mm) > WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); > WARN_ON_ONCE(!tsk->mm); > > - force_uaccess_end(to_kthread(tsk)->oldfs); > - > task_lock(tsk); > /* > * When a kthread stops operating on an address space, the loop > diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c > index 9c625257023d..9ed5ce989415 100644 > --- a/kernel/stacktrace.c > +++ b/kernel/stacktrace.c > @@ -226,15 +226,12 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) > .store = store, > .size = size, > }; > - mm_segment_t fs; > > /* Trace user stack if not a kernel thread */ > if (current->flags & PF_KTHREAD) > return 0; > > - fs = force_uaccess_begin(); > arch_stack_walk_user(consume_entry, &c, task_pt_regs(current)); > - force_uaccess_end(fs); > > return c.len; > } > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 21aa30644219..8115fff17018 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -332,8 +332,6 @@ BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, > if (unlikely(in_interrupt() || > current->flags & (PF_KTHREAD | PF_EXITING))) > return -EPERM; > - if (unlikely(uaccess_kernel())) > - return -EPERM; > if (unlikely(!nmi_uaccess_okay())) > return -EPERM; > > @@ -835,8 +833,6 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) > */ > if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) > return -EPERM; > - if (unlikely(uaccess_kernel())) > - return -EPERM; > if (unlikely(!nmi_uaccess_okay())) > return -EPERM; > > diff --git a/mm/maccess.c b/mm/maccess.c > index cbd1b3959af2..106820b33a2b 100644 > --- a/mm/maccess.c > +++ b/mm/maccess.c > @@ -113,14 +113,11 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) > long copy_from_user_nofault(void *dst, const void __user *src, size_t size) > { > long ret = -EFAULT; > - mm_segment_t old_fs = force_uaccess_begin(); > - > if (access_ok(src, size)) { > pagefault_disable(); > ret = __copy_from_user_inatomic(dst, src, size); > pagefault_enable(); > } > - force_uaccess_end(old_fs); > > if (ret) > return -EFAULT; > @@ -140,14 +137,12 @@ EXPORT_SYMBOL_GPL(copy_from_user_nofault); > long copy_to_user_nofault(void __user *dst, const void *src, size_t size) > { > long ret = -EFAULT; > - mm_segment_t old_fs = force_uaccess_begin(); > > if (access_ok(dst, size)) { > pagefault_disable(); > ret = __copy_to_user_inatomic(dst, src, size); > pagefault_enable(); > } > - force_uaccess_end(old_fs); > > if (ret) > return -EFAULT; > @@ -176,17 +171,14 @@ EXPORT_SYMBOL_GPL(copy_to_user_nofault); > long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr, > long count) > { > - mm_segment_t old_fs; > long ret; > > if (unlikely(count <= 0)) > return 0; > > - old_fs = force_uaccess_begin(); > pagefault_disable(); > ret = strncpy_from_user(dst, unsafe_addr, count); > pagefault_enable(); > - force_uaccess_end(old_fs); > > if (ret >= count) { > ret = count; > @@ -216,14 +208,11 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr, > */ > long strnlen_user_nofault(const void __user *unsafe_addr, long count) > { > - mm_segment_t old_fs; > int ret; > > - old_fs = force_uaccess_begin(); > pagefault_disable(); > ret = strnlen_user(unsafe_addr, count); > pagefault_enable(); > - force_uaccess_end(old_fs); > > return ret; > } > diff --git a/mm/memory.c b/mm/memory.c > index c125c4969913..9a6ebf68a846 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5256,14 +5256,6 @@ void print_vma_addr(char *prefix, unsigned long ip) > #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) > void __might_fault(const char *file, int line) > { > - /* > - * Some code (nfs/sunrpc) uses socket ops on kernel memory while > - * holding the mmap_lock, this is safe because kernel memory doesn't > - * get paged out, therefore we'll never actually fault, and the > - * below annotations will generate false positives. > - */ > - if (uaccess_kernel()) > - return; > if (pagefault_disabled()) > return; > __might_sleep(file, line); > diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c > index 51a941b56ec3..422ec6e7ccff 100644 Acked-by: Stafford Horne <shorne@gmail.com> [openrisc, asm-generic] Thanks!
On 2/16/22 07:13, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > There are no remaining callers of set_fs(), so CONFIG_SET_FS > can be removed globally, along with the thread_info field and > any references to it. > > This turns access_ok() into a cheaper check against TASK_SIZE_MAX. > > With CONFIG_SET_FS gone, so drop all remaining references to > set_fs()/get_fs(), mm_segment_t and uaccess_kernel(). > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/Kconfig | 3 - > arch/alpha/Kconfig | 1 - > arch/alpha/include/asm/processor.h | 4 -- > arch/alpha/include/asm/thread_info.h | 2 - > arch/alpha/include/asm/uaccess.h | 19 ------ > arch/arc/Kconfig | 1 - > arch/arc/include/asm/segment.h | 20 ------- > arch/arc/include/asm/thread_info.h | 3 - > arch/arc/include/asm/uaccess.h | 1 - > arch/arm/lib/uaccess_with_memcpy.c | 10 ---- > arch/csky/Kconfig | 1 - > arch/csky/include/asm/processor.h | 2 - > arch/csky/include/asm/segment.h | 10 ---- > arch/csky/include/asm/thread_info.h | 2 - > arch/csky/include/asm/uaccess.h | 3 - > arch/csky/kernel/asm-offsets.c | 1 - > arch/h8300/Kconfig | 1 - > arch/h8300/include/asm/processor.h | 1 - > arch/h8300/include/asm/segment.h | 40 ------------- > arch/h8300/include/asm/thread_info.h | 3 - > arch/h8300/kernel/entry.S | 1 - > arch/h8300/kernel/head_ram.S | 1 - > arch/h8300/mm/init.c | 6 -- > arch/h8300/mm/memory.c | 1 - > arch/hexagon/Kconfig | 1 - > arch/hexagon/include/asm/thread_info.h | 6 -- > arch/hexagon/kernel/process.c | 1 - > arch/microblaze/Kconfig | 1 - > arch/microblaze/include/asm/thread_info.h | 6 -- > arch/microblaze/include/asm/uaccess.h | 24 -------- > arch/microblaze/kernel/asm-offsets.c | 1 - > arch/microblaze/kernel/process.c | 1 - > arch/nds32/Kconfig | 1 - > arch/nds32/include/asm/thread_info.h | 4 -- > arch/nds32/include/asm/uaccess.h | 15 +---- > arch/nds32/kernel/process.c | 5 +- > arch/nds32/mm/alignment.c | 3 - > arch/nios2/Kconfig | 1 - > arch/nios2/include/asm/thread_info.h | 9 --- > arch/nios2/include/asm/uaccess.h | 12 ---- For NIOS2: Acked-by: Dinh Nguyen <dinguyen@kernel.org>
diff --git a/arch/Kconfig b/arch/Kconfig index fa5db36bda67..99349547afed 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -24,9 +24,6 @@ config KEXEC_ELF config HAVE_IMA_KEXEC bool -config SET_FS - bool - config HOTPLUG_SMT bool diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 4e87783c90ad..eee8b5b0a58b 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -35,7 +35,6 @@ config ALPHA select OLD_SIGSUSPEND select CPU_NO_EFFICIENT_FFS if !ALPHA_EV67 select MMU_GATHER_NO_RANGE - select SET_FS select SPARSEMEM_EXTREME if SPARSEMEM select ZONE_DMA help diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h index 090499c99c1c..43e234c518b1 100644 --- a/arch/alpha/include/asm/processor.h +++ b/arch/alpha/include/asm/processor.h @@ -26,10 +26,6 @@ #define TASK_UNMAPPED_BASE \ ((current->personality & ADDR_LIMIT_32BIT) ? 0x40000000 : TASK_SIZE / 2) -typedef struct { - unsigned long seg; -} mm_segment_t; - /* This is dead. Everything has been moved to thread_info. */ struct thread_struct { }; #define INIT_THREAD { } diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h index 2592356e3215..fdc485d7787a 100644 --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -19,7 +19,6 @@ struct thread_info { unsigned int flags; /* low level flags */ unsigned int ieee_state; /* see fpu.h */ - mm_segment_t addr_limit; /* thread address space */ unsigned cpu; /* current CPU */ int preempt_count; /* 0 => preemptable, <0 => BUG */ unsigned int status; /* thread-synchronous flags */ @@ -35,7 +34,6 @@ struct thread_info { #define INIT_THREAD_INFO(tsk) \ { \ .task = &tsk, \ - .addr_limit = KERNEL_DS, \ .preempt_count = INIT_PREEMPT_COUNT, \ } diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h index 82c5743fc9cd..c32c2584c0b7 100644 --- a/arch/alpha/include/asm/uaccess.h +++ b/arch/alpha/include/asm/uaccess.h @@ -2,26 +2,7 @@ #ifndef __ALPHA_UACCESS_H #define __ALPHA_UACCESS_H -/* - * The fs value determines whether argument validity checking should be - * performed or not. If get_fs() == USER_DS, checking is performed, with - * get_fs() == KERNEL_DS, checking is bypassed. - * - * Or at least it did once upon a time. Nowadays it is a mask that - * defines which bits of the address space are off limits. This is a - * wee bit faster than the above. - * - * For historical reasons, these macros are grossly misnamed. - */ - -#define KERNEL_DS ((mm_segment_t) { 0UL }) -#define USER_DS ((mm_segment_t) { -0x40000000000UL }) - -#define get_fs() (current_thread_info()->addr_limit) -#define set_fs(x) (current_thread_info()->addr_limit = (x)) - #include <asm-generic/access_ok.h> - /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 3c2a4753d09b..e0a60a27e14d 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -45,7 +45,6 @@ config ARC select PCI_SYSCALL if PCI select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING select HAVE_ARCH_JUMP_LABEL if ISA_ARCV2 && !CPU_ENDIAN_BE32 - select SET_FS select TRACE_IRQFLAGS_SUPPORT config LOCKDEP_SUPPORT diff --git a/arch/arc/include/asm/segment.h b/arch/arc/include/asm/segment.h deleted file mode 100644 index 871f8ab11bfd..000000000000 --- a/arch/arc/include/asm/segment.h +++ /dev/null @@ -1,20 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) - */ - -#ifndef __ASMARC_SEGMENT_H -#define __ASMARC_SEGMENT_H - -#ifndef __ASSEMBLY__ - -typedef unsigned long mm_segment_t; - -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) - -#define KERNEL_DS MAKE_MM_SEG(0) -#define USER_DS MAKE_MM_SEG(TASK_SIZE) -#define uaccess_kernel() (get_fs() == KERNEL_DS) - -#endif /* __ASSEMBLY__ */ -#endif /* __ASMARC_SEGMENT_H */ diff --git a/arch/arc/include/asm/thread_info.h b/arch/arc/include/asm/thread_info.h index d36863e34bfc..1e0b2e3914d5 100644 --- a/arch/arc/include/asm/thread_info.h +++ b/arch/arc/include/asm/thread_info.h @@ -27,7 +27,6 @@ #ifndef __ASSEMBLY__ #include <linux/thread_info.h> -#include <asm/segment.h> /* * low level task data that entry.S needs immediate access to @@ -40,7 +39,6 @@ struct thread_info { unsigned long flags; /* low level flags */ int preempt_count; /* 0 => preemptable, <0 => BUG */ struct task_struct *task; /* main task structure */ - mm_segment_t addr_limit; /* thread address space */ __u32 cpu; /* current CPU */ unsigned long thr_ptr; /* TLS ptr */ }; @@ -56,7 +54,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } static inline __attribute_const__ struct thread_info *current_thread_info(void) diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 30f80b4be2ab..99712471c96a 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -638,7 +638,6 @@ extern unsigned long arc_clear_user_noinline(void __user *to, #define __clear_user(d, n) arc_clear_user_noinline(d, n) #endif -#include <asm/segment.h> #include <asm-generic/uaccess.h> #endif diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c index 106f83a5ea6d..c30b689bec2e 100644 --- a/arch/arm/lib/uaccess_with_memcpy.c +++ b/arch/arm/lib/uaccess_with_memcpy.c @@ -92,11 +92,6 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n) unsigned long ua_flags; int atomic; - if (uaccess_kernel()) { - memcpy((void *)to, from, n); - return 0; - } - /* the mmap semaphore is taken only if not in an atomic context */ atomic = faulthandler_disabled(); @@ -165,11 +160,6 @@ __clear_user_memset(void __user *addr, unsigned long n) { unsigned long ua_flags; - if (uaccess_kernel()) { - memset((void *)addr, 0, n); - return 0; - } - mmap_read_lock(current->mm); while (n) { pte_t *pte; diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 132f43f12dd8..75ef86605d69 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -79,7 +79,6 @@ config CSKY select PCI_DOMAINS_GENERIC if PCI select PCI_SYSCALL if PCI select PCI_MSI if PCI - select SET_FS select TRACE_IRQFLAGS_SUPPORT config LOCKDEP_SUPPORT diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h index 817dd60ff152..688c7548b559 100644 --- a/arch/csky/include/asm/processor.h +++ b/arch/csky/include/asm/processor.h @@ -4,7 +4,6 @@ #define __ASM_CSKY_PROCESSOR_H #include <linux/bitops.h> -#include <asm/segment.h> #include <asm/ptrace.h> #include <asm/current.h> #include <asm/cache.h> @@ -59,7 +58,6 @@ struct thread_struct { */ #define start_thread(_regs, _pc, _usp) \ do { \ - set_fs(USER_DS); /* reads from user space */ \ (_regs)->pc = (_pc); \ (_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */ \ (_regs)->regs[2] = 0; \ diff --git a/arch/csky/include/asm/segment.h b/arch/csky/include/asm/segment.h deleted file mode 100644 index 5bc1cc62b87f..000000000000 --- a/arch/csky/include/asm/segment.h +++ /dev/null @@ -1,10 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#ifndef __ASM_CSKY_SEGMENT_H -#define __ASM_CSKY_SEGMENT_H - -typedef struct { - unsigned long seg; -} mm_segment_t; - -#endif /* __ASM_CSKY_SEGMENT_H */ diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index 8c349a8f904d..b5ed788f0c68 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -16,7 +16,6 @@ struct thread_info { unsigned long flags; int preempt_count; unsigned long tp_value; - mm_segment_t addr_limit; struct restart_block restart_block; struct pt_regs *regs; unsigned int cpu; @@ -26,7 +25,6 @@ struct thread_info { { \ .task = &tsk, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ .cpu = 0, \ .restart_block = { \ .fn = do_no_restart_syscall, \ diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h index fec8f77ffc99..2e927c21d8a1 100644 --- a/arch/csky/include/asm/uaccess.h +++ b/arch/csky/include/asm/uaccess.h @@ -3,8 +3,6 @@ #ifndef __ASM_CSKY_UACCESS_H #define __ASM_CSKY_UACCESS_H -#define user_addr_max() (current_thread_info()->addr_limit.seg) - /* * __put_user_fn */ @@ -200,7 +198,6 @@ unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n); unsigned long __clear_user(void __user *to, unsigned long n); #define __clear_user __clear_user -#include <asm/segment.h> #include <asm-generic/uaccess.h> #endif /* __ASM_CSKY_UACCESS_H */ diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c index 1cbcba4b0dd1..d1e903579473 100644 --- a/arch/csky/kernel/asm-offsets.c +++ b/arch/csky/kernel/asm-offsets.c @@ -25,7 +25,6 @@ int main(void) /* offsets into the thread_info struct */ DEFINE(TINFO_FLAGS, offsetof(struct thread_info, flags)); DEFINE(TINFO_PREEMPT, offsetof(struct thread_info, preempt_count)); - DEFINE(TINFO_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); DEFINE(TINFO_TP_VALUE, offsetof(struct thread_info, tp_value)); DEFINE(TINFO_TASK, offsetof(struct thread_info, task)); diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index 3e3e0f16f7e0..fe48c4f26cc8 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -24,7 +24,6 @@ config H8300 select HAVE_ARCH_KGDB select HAVE_ARCH_HASH select CPU_NO_EFFICIENT_FFS - select SET_FS select UACCESS_MEMCPY config CPU_BIG_ENDIAN diff --git a/arch/h8300/include/asm/processor.h b/arch/h8300/include/asm/processor.h index 141a23eb62b7..ba171aa4dacb 100644 --- a/arch/h8300/include/asm/processor.h +++ b/arch/h8300/include/asm/processor.h @@ -13,7 +13,6 @@ #define __ASM_H8300_PROCESSOR_H #include <linux/compiler.h> -#include <asm/segment.h> #include <asm/ptrace.h> #include <asm/current.h> diff --git a/arch/h8300/include/asm/segment.h b/arch/h8300/include/asm/segment.h deleted file mode 100644 index 37950725d9b9..000000000000 --- a/arch/h8300/include/asm/segment.h +++ /dev/null @@ -1,40 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _H8300_SEGMENT_H -#define _H8300_SEGMENT_H - -/* define constants */ -#define USER_DATA (1) -#ifndef __USER_DS -#define __USER_DS (USER_DATA) -#endif -#define USER_PROGRAM (2) -#define SUPER_DATA (3) -#ifndef __KERNEL_DS -#define __KERNEL_DS (SUPER_DATA) -#endif -#define SUPER_PROGRAM (4) - -#ifndef __ASSEMBLY__ - -typedef struct { - unsigned long seg; -} mm_segment_t; - -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) -#define USER_DS MAKE_MM_SEG(__USER_DS) -#define KERNEL_DS MAKE_MM_SEG(__KERNEL_DS) - -/* - * Get/set the SFC/DFC registers for MOVES instructions - */ - -static inline mm_segment_t get_fs(void) -{ - return USER_DS; -} - -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) - -#endif /* __ASSEMBLY__ */ - -#endif /* _H8300_SEGMENT_H */ diff --git a/arch/h8300/include/asm/thread_info.h b/arch/h8300/include/asm/thread_info.h index a518214d4ddd..ff2d873749a4 100644 --- a/arch/h8300/include/asm/thread_info.h +++ b/arch/h8300/include/asm/thread_info.h @@ -10,7 +10,6 @@ #define _ASM_THREAD_INFO_H #include <asm/page.h> -#include <asm/segment.h> #ifdef __KERNEL__ @@ -31,7 +30,6 @@ struct thread_info { unsigned long flags; /* low level flags */ int cpu; /* cpu we're on */ int preempt_count; /* 0 => preemptable, <0 => BUG */ - mm_segment_t addr_limit; }; /* @@ -43,7 +41,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } /* how to get the thread information struct from C */ diff --git a/arch/h8300/kernel/entry.S b/arch/h8300/kernel/entry.S index c6e289b5f1f2..42db87c17917 100644 --- a/arch/h8300/kernel/entry.S +++ b/arch/h8300/kernel/entry.S @@ -17,7 +17,6 @@ #include <linux/sys.h> #include <asm/unistd.h> #include <asm/setup.h> -#include <asm/segment.h> #include <asm/linkage.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> diff --git a/arch/h8300/kernel/head_ram.S b/arch/h8300/kernel/head_ram.S index dbf8429f5fab..489462f0ee57 100644 --- a/arch/h8300/kernel/head_ram.S +++ b/arch/h8300/kernel/head_ram.S @@ -4,7 +4,6 @@ #include <linux/init.h> #include <asm/unistd.h> #include <asm/setup.h> -#include <asm/segment.h> #include <asm/linkage.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> diff --git a/arch/h8300/mm/init.c b/arch/h8300/mm/init.c index f7bf4693e3b2..9fa13312720a 100644 --- a/arch/h8300/mm/init.c +++ b/arch/h8300/mm/init.c @@ -34,7 +34,6 @@ #include <linux/gfp.h> #include <asm/setup.h> -#include <asm/segment.h> #include <asm/page.h> #include <asm/sections.h> @@ -71,11 +70,6 @@ void __init paging_init(void) panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, PAGE_SIZE, PAGE_SIZE); - /* - * Set up SFC/DFC registers (user data space). - */ - set_fs(USER_DS); - pr_debug("before free_area_init\n"); pr_debug("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n", diff --git a/arch/h8300/mm/memory.c b/arch/h8300/mm/memory.c index 4a60e2b5eb96..c950571064d2 100644 --- a/arch/h8300/mm/memory.c +++ b/arch/h8300/mm/memory.c @@ -24,7 +24,6 @@ #include <linux/types.h> #include <asm/setup.h> -#include <asm/segment.h> #include <asm/page.h> #include <asm/traps.h> #include <asm/io.h> diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index 15dd8f38b698..54eadf265178 100644 --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -30,7 +30,6 @@ config HEXAGON select GENERIC_CLOCKEVENTS_BROADCAST select MODULES_USE_ELF_RELA select GENERIC_CPU_DEVICES - select SET_FS select ARCH_WANT_LD_ORPHAN_WARN select TRACE_IRQFLAGS_SUPPORT help diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h index 535976665bf0..e90f280b9ce3 100644 --- a/arch/hexagon/include/asm/thread_info.h +++ b/arch/hexagon/include/asm/thread_info.h @@ -22,10 +22,6 @@ #ifndef __ASSEMBLY__ -typedef struct { - unsigned long seg; -} mm_segment_t; - /* * This is union'd with the "bottom" of the kernel stack. * It keeps track of thread info which is handy for routines @@ -37,7 +33,6 @@ struct thread_info { unsigned long flags; /* low level flags */ __u32 cpu; /* current cpu */ int preempt_count; /* 0=>preemptible,<0=>BUG */ - mm_segment_t addr_limit; /* segmentation sux */ /* * used for syscalls somehow; * seems to have a function pointer and four arguments @@ -66,7 +61,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = 1, \ - .addr_limit = KERNEL_DS, \ .sp = 0, \ .regs = NULL, \ } diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c index 232dfd8956aa..dfa6b2757c05 100644 --- a/arch/hexagon/kernel/process.c +++ b/arch/hexagon/kernel/process.c @@ -105,7 +105,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, /* * Parent sees new pid -- not necessary, not even possible at * this point in the fork process - * Might also want to set things like ti->addr_limit */ return 0; diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 59798e43cdb0..1fb1cec087b7 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -42,7 +42,6 @@ config MICROBLAZE select CPU_NO_EFFICIENT_FFS select MMU_GATHER_NO_RANGE select SPARSE_IRQ - select SET_FS select ZONE_DMA select TRACE_IRQFLAGS_SUPPORT diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h index 44f5ca331862..a0ddd2a36fb9 100644 --- a/arch/microblaze/include/asm/thread_info.h +++ b/arch/microblaze/include/asm/thread_info.h @@ -56,17 +56,12 @@ struct cpu_context { __u32 fsr; }; -typedef struct { - unsigned long seg; -} mm_segment_t; - struct thread_info { struct task_struct *task; /* main task structure */ unsigned long flags; /* low level flags */ unsigned long status; /* thread-synchronous flags */ __u32 cpu; /* current CPU */ __s32 preempt_count; /* 0 => preemptable,< 0 => BUG*/ - mm_segment_t addr_limit; /* thread address space */ struct cpu_context cpu_context; }; @@ -80,7 +75,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } /* how to get the thread information struct from C */ diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index bf9b7657a65a..3aab2f17e046 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -15,30 +15,6 @@ #include <linux/pgtable.h> #include <asm/extable.h> #include <linux/string.h> - -/* - * On Microblaze the fs value is actually the top of the corresponding - * address space. - * - * The fs value determines whether argument validity checking should be - * performed or not. If get_fs() == USER_DS, checking is performed, with - * get_fs() == KERNEL_DS, checking is bypassed. - * - * For historical reasons, these macros are grossly misnamed. - * - * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. - */ -# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) - -# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) -# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) - -# define get_fs() (current_thread_info()->addr_limit) -# define set_fs(val) (current_thread_info()->addr_limit = (val)) -# define user_addr_max() get_fs().seg - -# define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) - #include <asm-generic/access_ok.h> # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" diff --git a/arch/microblaze/kernel/asm-offsets.c b/arch/microblaze/kernel/asm-offsets.c index b77dd188dec4..47ee409508b1 100644 --- a/arch/microblaze/kernel/asm-offsets.c +++ b/arch/microblaze/kernel/asm-offsets.c @@ -86,7 +86,6 @@ int main(int argc, char *argv[]) /* struct thread_info */ DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); - DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); DEFINE(TI_CPU_CONTEXT, offsetof(struct thread_info, cpu_context)); DEFINE(TI_PREEMPT_COUNT, offsetof(struct thread_info, preempt_count)); BLANK(); diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c index 5e2b91c1e8ce..1b944d319d73 100644 --- a/arch/microblaze/kernel/process.c +++ b/arch/microblaze/kernel/process.c @@ -18,7 +18,6 @@ #include <linux/tick.h> #include <linux/bitops.h> #include <linux/ptrace.h> -#include <linux/uaccess.h> /* for USER_DS macros */ #include <asm/cacheflush.h> void show_regs(struct pt_regs *regs) diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig index 4d1421b18734..013249430fa3 100644 --- a/arch/nds32/Kconfig +++ b/arch/nds32/Kconfig @@ -44,7 +44,6 @@ config NDS32 select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE - select SET_FS select TRACE_IRQFLAGS_SUPPORT help Andes(nds32) Linux support. diff --git a/arch/nds32/include/asm/thread_info.h b/arch/nds32/include/asm/thread_info.h index d3967ad184f0..bd8f81cf2ce5 100644 --- a/arch/nds32/include/asm/thread_info.h +++ b/arch/nds32/include/asm/thread_info.h @@ -16,8 +16,6 @@ struct task_struct; #include <asm/ptrace.h> #include <asm/types.h> -typedef unsigned long mm_segment_t; - /* * low level task data that entry.S needs immediate access to. * __switch_to() assumes cpu_context follows immediately after cpu_domain. @@ -25,12 +23,10 @@ typedef unsigned long mm_segment_t; struct thread_info { unsigned long flags; /* low level flags */ __s32 preempt_count; /* 0 => preemptable, <0 => bug */ - mm_segment_t addr_limit; /* address limit */ }; #define INIT_THREAD_INFO(tsk) \ { \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } #define thread_saved_pc(tsk) ((unsigned long)(tsk->thread.cpu_context.pc)) #define thread_saved_fp(tsk) ((unsigned long)(tsk->thread.cpu_context.fp)) diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h index 832d642a4068..377548d4451a 100644 --- a/arch/nds32/include/asm/uaccess.h +++ b/arch/nds32/include/asm/uaccess.h @@ -11,6 +11,7 @@ #include <asm/errno.h> #include <asm/memory.h> #include <asm/types.h> +#include <asm-generic/access_ok.h> #define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t" @@ -33,20 +34,6 @@ struct exception_table_entry { extern int fixup_exception(struct pt_regs *regs); -#define KERNEL_DS ((mm_segment_t) { ~0UL }) -#define USER_DS ((mm_segment_t) {TASK_SIZE - 1}) - -#define get_fs() (current_thread_info()->addr_limit) -#define user_addr_max get_fs -#define uaccess_kernel() (get_fs() == KERNEL_DS) - -static inline void set_fs(mm_segment_t fs) -{ - current_thread_info()->addr_limit = fs; -} - -#include <asm-generic/access_ok.h> - /* * Single-value transfer routines. They automatically use the right * size if we just have the right pointer type. Note that the functions diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c index 49fab9e39cbf..d35c1f63fa11 100644 --- a/arch/nds32/kernel/process.c +++ b/arch/nds32/kernel/process.c @@ -119,9 +119,8 @@ void show_regs(struct pt_regs *regs) regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]); pr_info("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]); - pr_info(" IRQs o%s Segment %s\n", - interrupts_enabled(regs) ? "n" : "ff", - uaccess_kernel() ? "kernel" : "user"); + pr_info(" IRQs o%s Segment user\n", + interrupts_enabled(regs) ? "n" : "ff"); } EXPORT_SYMBOL(show_regs); diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c index 1eb7ded6992b..9c2c0a454da8 100644 --- a/arch/nds32/mm/alignment.c +++ b/arch/nds32/mm/alignment.c @@ -512,7 +512,6 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs) { unsigned long inst; int ret = -EFAULT; - mm_segment_t seg; inst = get_inst(regs->ipc); @@ -520,12 +519,10 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs) "Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr, regs->ipc, inst); - seg = force_uaccess_begin(); if (inst & NDS32_16BIT_INSTRUCTION) ret = do_16((inst >> 16) & 0xffff, regs); else ret = do_32(inst, regs); - force_uaccess_end(seg); return ret; } diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig index 33fd06f5fa41..4167f1eb4cd8 100644 --- a/arch/nios2/Kconfig +++ b/arch/nios2/Kconfig @@ -24,7 +24,6 @@ config NIOS2 select USB_ARCH_HAS_HCD if USB_SUPPORT select CPU_NO_EFFICIENT_FFS select MMU_GATHER_NO_RANGE if MMU - select SET_FS config GENERIC_CSUM def_bool y diff --git a/arch/nios2/include/asm/thread_info.h b/arch/nios2/include/asm/thread_info.h index 272d2c72a727..bcc0e9915ebd 100644 --- a/arch/nios2/include/asm/thread_info.h +++ b/arch/nios2/include/asm/thread_info.h @@ -26,10 +26,6 @@ #ifndef __ASSEMBLY__ -typedef struct { - unsigned long seg; -} mm_segment_t; - /* * low level task data that entry.S needs immediate access to * - this struct should fit entirely inside of one cache line @@ -42,10 +38,6 @@ struct thread_info { unsigned long flags; /* low level flags */ __u32 cpu; /* current CPU */ int preempt_count; /* 0 => preemptable,<0 => BUG */ - mm_segment_t addr_limit; /* thread address space: - 0-0x7FFFFFFF for user-thead - 0-0xFFFFFFFF for kernel-thread - */ struct pt_regs *regs; }; @@ -60,7 +52,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } /* how to get the thread information struct from C */ diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h index 6664ddc0e8e5..b8299082adbe 100644 --- a/arch/nios2/include/asm/uaccess.h +++ b/arch/nios2/include/asm/uaccess.h @@ -18,18 +18,6 @@ #include <asm/page.h> #include <asm/extable.h> - -/* - * Segment stuff - */ -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) -#define USER_DS MAKE_MM_SEG(0x80000000UL) -#define KERNEL_DS MAKE_MM_SEG(0) - - -#define get_fs() (current_thread_info()->addr_limit) -#define set_fs(seg) (current_thread_info()->addr_limit = (seg)) - #include <asm-generic/access_ok.h> # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig index f724b3f1aeed..0d68adf6e02b 100644 --- a/arch/openrisc/Kconfig +++ b/arch/openrisc/Kconfig @@ -36,7 +36,6 @@ config OPENRISC select ARCH_WANT_FRAME_POINTERS select GENERIC_IRQ_MULTI_HANDLER select MMU_GATHER_NO_RANGE if MMU - select SET_FS select TRACE_IRQFLAGS_SUPPORT config CPU_BIG_ENDIAN diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h index 659834ab87fa..4af3049c34c2 100644 --- a/arch/openrisc/include/asm/thread_info.h +++ b/arch/openrisc/include/asm/thread_info.h @@ -40,18 +40,12 @@ */ #ifndef __ASSEMBLY__ -typedef unsigned long mm_segment_t; - struct thread_info { struct task_struct *task; /* main task structure */ unsigned long flags; /* low level flags */ __u32 cpu; /* current CPU */ __s32 preempt_count; /* 0 => preemptable, <0 => BUG */ - mm_segment_t addr_limit; /* thread address space: - 0-0x7FFFFFFF for user-thead - 0-0xFFFFFFFF for kernel-thread - */ __u8 supervisor_stack[0]; /* saved context data */ @@ -71,7 +65,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ .ksp = 0, \ } diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h index 8f049ec99b3e..d6500a374e18 100644 --- a/arch/openrisc/include/asm/uaccess.h +++ b/arch/openrisc/include/asm/uaccess.h @@ -22,29 +22,6 @@ #include <linux/string.h> #include <asm/page.h> #include <asm/extable.h> - -/* - * The fs value determines whether argument validity checking should be - * performed or not. If get_fs() == USER_DS, checking is performed, with - * get_fs() == KERNEL_DS, checking is bypassed. - * - * For historical reasons, these macros are grossly misnamed. - */ - -/* addr_limit is the maximum accessible address for the task. we misuse - * the KERNEL_DS and USER_DS values to both assign and compare the - * addr_limit values through the equally misnamed get/set_fs macros. - * (see above) - */ - -#define KERNEL_DS (~0UL) - -#define USER_DS (TASK_SIZE) -#define get_fs() (current_thread_info()->addr_limit) -#define set_fs(x) (current_thread_info()->addr_limit = (x)) - -#define uaccess_kernel() (get_fs() == KERNEL_DS) - #include <asm-generic/access_ok.h> /* diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h index b5835325d44b..3222206cb3ea 100644 --- a/arch/parisc/include/asm/futex.h +++ b/arch/parisc/include/asm/futex.h @@ -96,12 +96,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 val; unsigned long flags; - /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is - * our gateway page, and causes no end of trouble... - */ - if (uaccess_kernel() && !uaddr) - return -EFAULT; - if (!access_ok(uaddr, sizeof(u32))) return -EFAULT; diff --git a/arch/parisc/lib/memcpy.c b/arch/parisc/lib/memcpy.c index ea70a0e08321..468704ce8a1c 100644 --- a/arch/parisc/lib/memcpy.c +++ b/arch/parisc/lib/memcpy.c @@ -13,7 +13,7 @@ #include <linux/compiler.h> #include <linux/uaccess.h> -#define get_user_space() (uaccess_kernel() ? 0 : mfsp(3)) +#define get_user_space() (mfsp(3)) #define get_kernel_space() (0) /* Returns 0 for success, otherwise, returns number of bytes not transferred. */ diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index 9f6f9bce5292..9276f321b3e3 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -46,7 +46,6 @@ config SPARC select LOCKDEP_SMALL if LOCKDEP select NEED_DMA_MAP_STATE select NEED_SG_DMA_LENGTH - select SET_FS select TRACE_IRQFLAGS_SUPPORT config SPARC32 @@ -101,6 +100,7 @@ config SPARC64 select HAVE_SETUP_PER_CPU_AREA select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK + select SET_FS config ARCH_PROC_KCORE_TEXT def_bool y diff --git a/arch/sparc/include/asm/processor_32.h b/arch/sparc/include/asm/processor_32.h index 647bf0ac7beb..b26c35336b51 100644 --- a/arch/sparc/include/asm/processor_32.h +++ b/arch/sparc/include/asm/processor_32.h @@ -32,10 +32,6 @@ struct fpq { }; #endif -typedef struct { - int seg; -} mm_segment_t; - /* The Sparc processor specific thread struct. */ struct thread_struct { struct pt_regs *kregs; @@ -50,11 +46,9 @@ struct thread_struct { unsigned long fsr; unsigned long fpqdepth; struct fpq fpqueue[16]; - mm_segment_t current_ds; }; #define INIT_THREAD { \ - .current_ds = KERNEL_DS, \ .kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \ } diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h index 367747116260..9fd6c53644b6 100644 --- a/arch/sparc/include/asm/uaccess_32.h +++ b/arch/sparc/include/asm/uaccess_32.h @@ -12,19 +12,6 @@ #include <linux/string.h> #include <asm/processor.h> - -/* Sparc is not segmented, however we need to be able to fool access_ok() - * when doing system calls from kernel mode legitimately. - * - * "For historical reasons, these macros are grossly misnamed." -Linus - */ - -#define KERNEL_DS ((mm_segment_t) { 0 }) -#define USER_DS ((mm_segment_t) { -1 }) - -#define get_fs() (current->thread.current_ds) -#define set_fs(val) ((current->thread.current_ds) = (val)) - #include <asm-generic/access_ok.h> /* Uh, these should become the main single-value transfer routines.. diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 2dc0bf9fe62e..88c0c14aaff0 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -300,7 +300,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, extern int nwindows; unsigned long psr; memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); - p->thread.current_ds = KERNEL_DS; ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); childregs->u_regs[UREG_G1] = sp; /* function */ childregs->u_regs[UREG_G2] = arg; @@ -311,7 +310,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, } memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); childregs->u_regs[UREG_FP] = sp; - p->thread.current_ds = USER_DS; ti->kpc = (((unsigned long) ret_from_fork) - 0x8); ti->kpsr = current->thread.fork_kpsr | PSR_PIL; ti->kwim = current->thread.fork_kwim; diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 8ac599aa6d99..09f7616a0b46 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -40,7 +40,6 @@ config XTENSA select IRQ_DOMAIN select MODULES_USE_ELF_RELA select PERF_USE_VMALLOC - select SET_FS select TRACE_IRQFLAGS_SUPPORT select VIRT_TO_BUS help diff --git a/arch/xtensa/include/asm/asm-uaccess.h b/arch/xtensa/include/asm/asm-uaccess.h index 7f6cf4151843..7cec869136e3 100644 --- a/arch/xtensa/include/asm/asm-uaccess.h +++ b/arch/xtensa/include/asm/asm-uaccess.h @@ -23,76 +23,6 @@ #include <asm/asm-offsets.h> #include <asm/processor.h> -/* - * These assembly macros mirror the C macros in asm/uaccess.h. They - * should always have identical functionality. See - * arch/xtensa/kernel/sys.S for usage. - */ - -#define KERNEL_DS 0 -#define USER_DS 1 - -/* - * get_fs reads current->thread.current_ds into a register. - * On Entry: - * <ad> anything - * <sp> stack - * On Exit: - * <ad> contains current->thread.current_ds - */ - .macro get_fs ad, sp - GET_CURRENT(\ad,\sp) -#if THREAD_CURRENT_DS > 1020 - addi \ad, \ad, TASK_THREAD - l32i \ad, \ad, THREAD_CURRENT_DS - TASK_THREAD -#else - l32i \ad, \ad, THREAD_CURRENT_DS -#endif - .endm - -/* - * set_fs sets current->thread.current_ds to some value. - * On Entry: - * <at> anything (temp register) - * <av> value to write - * <sp> stack - * On Exit: - * <at> destroyed (actually, current) - * <av> preserved, value to write - */ - .macro set_fs at, av, sp - GET_CURRENT(\at,\sp) - s32i \av, \at, THREAD_CURRENT_DS - .endm - -/* - * kernel_ok determines whether we should bypass addr/size checking. - * See the equivalent C-macro version below for clarity. - * On success, kernel_ok branches to a label indicated by parameter - * <success>. This implies that the macro falls through to the next - * insruction on an error. - * - * Note that while this macro can be used independently, we designed - * in for optimal use in the access_ok macro below (i.e., we fall - * through on error). - * - * On Entry: - * <at> anything (temp register) - * <success> label to branch to on success; implies - * fall-through macro on error - * <sp> stack pointer - * On Exit: - * <at> destroyed (actually, current->thread.current_ds) - */ - -#if ((KERNEL_DS != 0) || (USER_DS == 0)) -# error Assembly macro kernel_ok fails -#endif - .macro kernel_ok at, sp, success - get_fs \at, \sp - beqz \at, \success - .endm - /* * user_ok determines whether the access to user-space memory is allowed. * See the equivalent C-macro version below for clarity. @@ -147,7 +77,6 @@ * <at> destroyed */ .macro access_ok aa, as, at, sp, error - kernel_ok \at, \sp, .Laccess_ok_\@ user_ok \aa, \as, \at, \error .Laccess_ok_\@: .endm diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h index 37d3e9887fe7..abad7c3df46f 100644 --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -152,18 +152,12 @@ */ #define SPILL_SLOT_CALL12(sp, reg) (*(((unsigned long *)(sp)) - 16 + (reg))) -typedef struct { - unsigned long seg; -} mm_segment_t; - struct thread_struct { /* kernel's return address and stack pointer for context switching */ unsigned long ra; /* kernel's a0: return address and window call size */ unsigned long sp; /* kernel's a1: stack pointer */ - mm_segment_t current_ds; /* see uaccess.h for example uses */ - /* struct xtensa_cpuinfo info; */ unsigned long bad_vaddr; /* last user fault */ @@ -186,7 +180,6 @@ struct thread_struct { { \ ra: 0, \ sp: sizeof(init_stack) + (long) &init_stack, \ - current_ds: {0}, \ /*info: {0}, */ \ bad_vaddr: 0, \ bad_uaddr: 0, \ diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h index a312333a9add..f6fcbba1d02f 100644 --- a/arch/xtensa/include/asm/thread_info.h +++ b/arch/xtensa/include/asm/thread_info.h @@ -52,8 +52,6 @@ struct thread_info { __u32 cpu; /* current CPU */ __s32 preempt_count; /* 0 => preemptable,< 0 => BUG*/ - mm_segment_t addr_limit; /* thread address space */ - unsigned long cpenable; #if XCHAL_HAVE_EXCLUSIVE /* result of the most recent exclusive store */ @@ -81,7 +79,6 @@ struct thread_info { .flags = 0, \ .cpu = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ - .addr_limit = KERNEL_DS, \ } /* how to get the thread information struct from C */ diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h index 0edd9e4b23d0..56aec6d504fe 100644 --- a/arch/xtensa/include/asm/uaccess.h +++ b/arch/xtensa/include/asm/uaccess.h @@ -19,22 +19,6 @@ #include <linux/prefetch.h> #include <asm/types.h> #include <asm/extable.h> - -/* - * The fs value determines whether argument validity checking should - * be performed or not. If get_fs() == USER_DS, checking is - * performed, with get_fs() == KERNEL_DS, checking is bypassed. - * - * For historical reasons (Data Segment Register?), these macros are - * grossly misnamed. - */ - -#define KERNEL_DS ((mm_segment_t) { 0 }) -#define USER_DS ((mm_segment_t) { 1 }) - -#define get_fs() (current->thread.current_ds) -#define set_fs(val) (current->thread.current_ds = (val)) - #include <asm-generic/access_ok.h> /* diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c index dc5c83cad9be..f1fd1390d069 100644 --- a/arch/xtensa/kernel/asm-offsets.c +++ b/arch/xtensa/kernel/asm-offsets.c @@ -87,7 +87,6 @@ int main(void) OFFSET(TI_STSTUS, thread_info, status); OFFSET(TI_CPU, thread_info, cpu); OFFSET(TI_PRE_COUNT, thread_info, preempt_count); - OFFSET(TI_ADDR_LIMIT, thread_info, addr_limit); /* struct thread_info (offset from start_struct) */ DEFINE(THREAD_RA, offsetof (struct task_struct, thread.ra)); @@ -108,8 +107,6 @@ int main(void) #endif DEFINE(THREAD_XTREGS_USER, offsetof (struct thread_info, xtregs_user)); DEFINE(XTREGS_USER_SIZE, sizeof(xtregs_user_t)); - DEFINE(THREAD_CURRENT_DS, offsetof (struct task_struct, \ - thread.current_ds)); /* struct mm_struct */ DEFINE(MM_USERS, offsetof(struct mm_struct, mm_users)); diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 614adb510dbd..2a918aeb0af1 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -747,7 +747,7 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer, * copied from, so it's unsafe to allow this with elevated * privileges (e.g. from a setuid binary) or via kernel_write(). */ - if (file->f_cred != current_cred() || uaccess_kernel()) { + if (file->f_cred != current_cred()) { pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n", task_tgid_vnr(current), current->comm); ret = -EACCES; diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 6b43e97bd417..aaa2376b9d34 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -224,11 +224,6 @@ static int sg_check_file_access(struct file *filp, const char *caller) caller, task_tgid_vnr(current), current->comm); return -EPERM; } - if (uaccess_kernel()) { - pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n", - caller, task_tgid_vnr(current), current->comm); - return -EACCES; - } return 0; } diff --git a/fs/exec.c b/fs/exec.c index 79f2c9483302..bc68a0c089ac 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1303,12 +1303,6 @@ int begin_new_exec(struct linux_binprm * bprm) if (retval) goto out_unlock; - /* - * Ensure that the uaccess routines can actually operate on userspace - * pointers: - */ - force_uaccess_begin(); - if (me->flags & PF_KTHREAD) free_kthread_struct(me); me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | diff --git a/include/asm-generic/access_ok.h b/include/asm-generic/access_ok.h index 1aad8964d2ed..88a7cb5d9aad 100644 --- a/include/asm-generic/access_ok.h +++ b/include/asm-generic/access_ok.h @@ -16,16 +16,8 @@ #define TASK_SIZE_MAX TASK_SIZE #endif -#ifndef uaccess_kernel -#ifdef CONFIG_SET_FS -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -#else -#define uaccess_kernel() (0) -#endif -#endif - #ifndef user_addr_max -#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE_MAX) +#define user_addr_max() TASK_SIZE_MAX #endif #ifndef __access_ok diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index ebc685dc8d74..a5be9e61a2a2 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -8,6 +8,7 @@ * address space, e.g. all NOMMU machines. */ #include <linux/string.h> +#include <asm-generic/access_ok.h> #ifdef CONFIG_UACCESS_MEMCPY #include <asm/unaligned.h> @@ -94,30 +95,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) #define INLINE_COPY_TO_USER #endif /* CONFIG_UACCESS_MEMCPY */ -#ifdef CONFIG_SET_FS -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) - -#ifndef KERNEL_DS -#define KERNEL_DS MAKE_MM_SEG(~0UL) -#endif - -#ifndef USER_DS -#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) -#endif - -#ifndef get_fs -#define get_fs() (current_thread_info()->addr_limit) - -static inline void set_fs(mm_segment_t fs) -{ - current_thread_info()->addr_limit = fs; -} -#endif - -#endif /* CONFIG_SET_FS */ - -#include <asm-generic/access_ok.h> - /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 819c0cb00b6d..a34b0f9a9972 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -290,10 +290,6 @@ static inline void addr_limit_user_check(void) return; #endif - if (CHECK_DATA_CORRUPTION(uaccess_kernel(), - "Invalid address limit on user-mode return")) - force_sig(SIGKILL); - #ifdef TIF_FSCHECK clear_thread_flag(TIF_FSCHECK); #endif diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 2c31667e62e0..2421a41f3a8e 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -10,39 +10,6 @@ #include <asm/uaccess.h> -#ifdef CONFIG_SET_FS -/* - * Force the uaccess routines to be wired up for actual userspace access, - * overriding any possible set_fs(KERNEL_DS) still lingering around. Undone - * using force_uaccess_end below. - */ -static inline mm_segment_t force_uaccess_begin(void) -{ - mm_segment_t fs = get_fs(); - - set_fs(USER_DS); - return fs; -} - -static inline void force_uaccess_end(mm_segment_t oldfs) -{ - set_fs(oldfs); -} -#else /* CONFIG_SET_FS */ -typedef struct { - /* empty dummy */ -} mm_segment_t; - -static inline mm_segment_t force_uaccess_begin(void) -{ - return (mm_segment_t) { }; -} - -static inline void force_uaccess_end(mm_segment_t oldfs) -{ -} -#endif /* CONFIG_SET_FS */ - /* * Architectures should provide two primitives (raw_copy_{to,from}_user()) * and get rid of their private instances of copy_{to,from}_user() and diff --git a/include/rdma/ib.h b/include/rdma/ib.h index 83139b9ce409..f7c185ff7a11 100644 --- a/include/rdma/ib.h +++ b/include/rdma/ib.h @@ -75,7 +75,7 @@ struct sockaddr_ib { */ static inline bool ib_safe_file_access(struct file *filp) { - return filp->f_cred == current_cred() && !uaccess_kernel(); + return filp->f_cred == current_cred(); } #endif /* _RDMA_IB_H */ diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 58cbe357fb2b..1273be84392c 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -209,17 +209,13 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, } if (regs) { - mm_segment_t fs; - if (crosstask) goto exit_put; if (add_mark) perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); - fs = force_uaccess_begin(); perf_callchain_user(&ctx, regs); - force_uaccess_end(fs); } } diff --git a/kernel/events/core.c b/kernel/events/core.c index 57c7197838db..11ca7303d6df 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6746,7 +6746,6 @@ perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, unsigned long sp; unsigned int rem; u64 dyn_size; - mm_segment_t fs; /* * We dump: @@ -6764,9 +6763,7 @@ perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, /* Data. */ sp = perf_user_stack_pointer(regs); - fs = force_uaccess_begin(); rem = __output_copy_user(handle, (void *) sp, dump_size); - force_uaccess_end(fs); dyn_size = dump_size - rem; perf_output_skip(handle, rem); diff --git a/kernel/exit.c b/kernel/exit.c index b00a25bb4ab9..0884a75bc2f8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -737,20 +737,6 @@ void __noreturn do_exit(long code) WARN_ON(blk_needs_flush_plug(tsk)); - /* - * If do_dead is called because this processes oopsed, it's possible - * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before - * continuing. Amongst other possible reasons, this is to prevent - * mm_release()->clear_child_tid() from writing to a user-controlled - * kernel address. - * - * On uptodate architectures force_uaccess_begin is a noop. On - * architectures that still have set_fs/get_fs in addition to handling - * oopses handles kernel threads that run as set_fs(KERNEL_DS) by - * default. - */ - force_uaccess_begin(); - kcov_task_exit(tsk); coredump_task_exit(tsk); diff --git a/kernel/kthread.c b/kernel/kthread.c index 38c6dd822da8..16c2275d4b50 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -55,7 +55,6 @@ struct kthread { int result; int (*threadfn)(void *); void *data; - mm_segment_t oldfs; struct completion parked; struct completion exited; #ifdef CONFIG_BLK_CGROUP @@ -1441,8 +1440,6 @@ void kthread_use_mm(struct mm_struct *mm) mmdrop(active_mm); else smp_mb(); - - to_kthread(tsk)->oldfs = force_uaccess_begin(); } EXPORT_SYMBOL_GPL(kthread_use_mm); @@ -1457,8 +1454,6 @@ void kthread_unuse_mm(struct mm_struct *mm) WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); WARN_ON_ONCE(!tsk->mm); - force_uaccess_end(to_kthread(tsk)->oldfs); - task_lock(tsk); /* * When a kthread stops operating on an address space, the loop diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index 9c625257023d..9ed5ce989415 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -226,15 +226,12 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) .store = store, .size = size, }; - mm_segment_t fs; /* Trace user stack if not a kernel thread */ if (current->flags & PF_KTHREAD) return 0; - fs = force_uaccess_begin(); arch_stack_walk_user(consume_entry, &c, task_pt_regs(current)); - force_uaccess_end(fs); return c.len; } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 21aa30644219..8115fff17018 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -332,8 +332,6 @@ BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, if (unlikely(in_interrupt() || current->flags & (PF_KTHREAD | PF_EXITING))) return -EPERM; - if (unlikely(uaccess_kernel())) - return -EPERM; if (unlikely(!nmi_uaccess_okay())) return -EPERM; @@ -835,8 +833,6 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) */ if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) return -EPERM; - if (unlikely(uaccess_kernel())) - return -EPERM; if (unlikely(!nmi_uaccess_okay())) return -EPERM; diff --git a/mm/maccess.c b/mm/maccess.c index cbd1b3959af2..106820b33a2b 100644 --- a/mm/maccess.c +++ b/mm/maccess.c @@ -113,14 +113,11 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) long copy_from_user_nofault(void *dst, const void __user *src, size_t size) { long ret = -EFAULT; - mm_segment_t old_fs = force_uaccess_begin(); - if (access_ok(src, size)) { pagefault_disable(); ret = __copy_from_user_inatomic(dst, src, size); pagefault_enable(); } - force_uaccess_end(old_fs); if (ret) return -EFAULT; @@ -140,14 +137,12 @@ EXPORT_SYMBOL_GPL(copy_from_user_nofault); long copy_to_user_nofault(void __user *dst, const void *src, size_t size) { long ret = -EFAULT; - mm_segment_t old_fs = force_uaccess_begin(); if (access_ok(dst, size)) { pagefault_disable(); ret = __copy_to_user_inatomic(dst, src, size); pagefault_enable(); } - force_uaccess_end(old_fs); if (ret) return -EFAULT; @@ -176,17 +171,14 @@ EXPORT_SYMBOL_GPL(copy_to_user_nofault); long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr, long count) { - mm_segment_t old_fs; long ret; if (unlikely(count <= 0)) return 0; - old_fs = force_uaccess_begin(); pagefault_disable(); ret = strncpy_from_user(dst, unsafe_addr, count); pagefault_enable(); - force_uaccess_end(old_fs); if (ret >= count) { ret = count; @@ -216,14 +208,11 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr, */ long strnlen_user_nofault(const void __user *unsafe_addr, long count) { - mm_segment_t old_fs; int ret; - old_fs = force_uaccess_begin(); pagefault_disable(); ret = strnlen_user(unsafe_addr, count); pagefault_enable(); - force_uaccess_end(old_fs); return ret; } diff --git a/mm/memory.c b/mm/memory.c index c125c4969913..9a6ebf68a846 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5256,14 +5256,6 @@ void print_vma_addr(char *prefix, unsigned long ip) #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) void __might_fault(const char *file, int line) { - /* - * Some code (nfs/sunrpc) uses socket ops on kernel memory while - * holding the mmap_lock, this is safe because kernel memory doesn't - * get paged out, therefore we'll never actually fault, and the - * below annotations will generate false positives. - */ - if (uaccess_kernel()) - return; if (pagefault_disabled()) return; __might_sleep(file, line); diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 51a941b56ec3..422ec6e7ccff 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -70,7 +70,7 @@ static int bpfilter_process_sockopt(struct sock *sk, int optname, .addr = (uintptr_t)optval.user, .len = optlen, }; - if (uaccess_kernel() || sockptr_is_kernel(optval)) { + if (sockptr_is_kernel(optval)) { pr_err("kernel access not supported\n"); return -EFAULT; }