| Message ID | 9eeb4be3c4e91d4155d0c4c234858f4259c5993d.1466974736.git.luto@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jun 26, 2016 at 5:55 PM, Andy Lutomirski <luto@kernel.org> wrote: > Becuase sched.h and thread_info.h are a tangled mess, I turned > in_compat_syscall into a macro. If we had current_thread_struct() > or similar and we could use it from thread_info.h, then this would > be a bit cleaner. > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > arch/x86/entry/common.c | 4 ++-- > arch/x86/include/asm/processor.h | 12 ++++++++++++ > arch/x86/include/asm/syscall.h | 23 +++++------------------ > arch/x86/include/asm/thread_info.h | 23 ++++------------------- > arch/x86/kernel/asm-offsets.c | 1 - > arch/x86/kernel/fpu/init.c | 1 - > arch/x86/kernel/process_64.c | 4 ++-- > arch/x86/kernel/ptrace.c | 2 +- > 8 files changed, 26 insertions(+), 44 deletions(-) > > diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c > index ec138e538c44..c4150bec7982 100644 > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -271,7 +271,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) > * syscalls. The fixup is exercised by the ptrace_syscall_32 > * selftest. > */ > - ti->status &= ~TS_COMPAT; > + current->thread.status &= ~TS_COMPAT; > #endif > > user_enter(); > @@ -369,7 +369,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) > unsigned int nr = (unsigned int)regs->orig_ax; > > #ifdef CONFIG_IA32_EMULATION > - ti->status |= TS_COMPAT; > + current->thread.status |= TS_COMPAT; > #endif > > if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) { > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h > index a2e20d6d01fe..a75e720f6402 100644 > --- a/arch/x86/include/asm/processor.h > +++ b/arch/x86/include/asm/processor.h > @@ -388,6 +388,9 @@ struct thread_struct { > unsigned short fsindex; > unsigned short gsindex; > #endif > + > + u32 status; /* thread synchronous flags */ > + > #ifdef CONFIG_X86_32 > unsigned long ip; > #endif > @@ -437,6 +440,15 @@ struct thread_struct { > }; > > /* > + * Thread-synchronous status. > + * > + * This is different from the flags in that nobody else > + * ever touches our thread-synchronous status, so we don't > + * have to worry about atomic accesses. > + */ > +#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ > + > +/* > * Set IOPL bits in EFLAGS from given mask > */ > static inline void native_set_iopl_mask(unsigned mask) > diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h > index 999b7cd2e78c..17229e7e2a1c 100644 > --- a/arch/x86/include/asm/syscall.h > +++ b/arch/x86/include/asm/syscall.h > @@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task, > * TS_COMPAT is set for 32-bit syscall entries and then > * remains set until we return to user mode. > */ > - if (task_thread_info(task)->status & TS_COMPAT) > + if (task->thread.status & TS_COMPAT) > /* > * Sign-extend the value so (int)-EFOO becomes (long)-EFOO > * and will match correctly in comparisons. > @@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task, > unsigned long *args) > { > # ifdef CONFIG_IA32_EMULATION > - if (task_thread_info(task)->status & TS_COMPAT) > + if (task->thread.status & TS_COMPAT) > switch (i) { > case 0: > if (!n--) break; > @@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task, > const unsigned long *args) > { > # ifdef CONFIG_IA32_EMULATION > - if (task_thread_info(task)->status & TS_COMPAT) > + if (task->thread.status & TS_COMPAT) > switch (i) { > case 0: > if (!n--) break; > @@ -234,21 +234,8 @@ static inline void syscall_set_arguments(struct task_struct *task, > > static inline int syscall_get_arch(void) > { > -#ifdef CONFIG_IA32_EMULATION > - /* > - * TS_COMPAT is set for 32-bit syscall entry and then > - * remains set until we return to user mode. > - * > - * TIF_IA32 tasks should always have TS_COMPAT set at > - * system call time. > - * > - * x32 tasks should be considered AUDIT_ARCH_X86_64. > - */ > - if (task_thread_info(current)->status & TS_COMPAT) > - return AUDIT_ARCH_I386; > -#endif > - /* Both x32 and x86_64 are considered "64-bit". */ > - return AUDIT_ARCH_X86_64; > + /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ > + return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; > } > #endif /* CONFIG_X86_32 */ > > diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h > index b45ffdda3549..7b42c1e462ac 100644 > --- a/arch/x86/include/asm/thread_info.h > +++ b/arch/x86/include/asm/thread_info.h > @@ -55,7 +55,6 @@ struct task_struct; > struct thread_info { > struct task_struct *task; /* main task structure */ > __u32 flags; /* low level flags */ > - __u32 status; /* thread synchronous flags */ > __u32 cpu; /* current CPU */ > }; > > @@ -211,28 +210,14 @@ static inline unsigned long current_stack_pointer(void) > > #endif > > -/* > - * Thread-synchronous status. > - * > - * This is different from the flags in that nobody else > - * ever touches our thread-synchronous status, so we don't > - * have to worry about atomic accesses. > - */ > -#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ > - > #ifndef __ASSEMBLY__ > > -static inline bool in_ia32_syscall(void) > -{ > #ifdef CONFIG_X86_32 > - return true; > -#endif > -#ifdef CONFIG_IA32_EMULATION > - if (current_thread_info()->status & TS_COMPAT) > - return true; > +#define in_ia32_syscall() true > +#else > +#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \ > + current->thread.status & TS_COMPAT) > #endif > - return false; > -} > > /* > * Force syscall return via IRET by making it look as if there was > diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c > index 2bd5c6ff7ee7..a91a6ead24a2 100644 > --- a/arch/x86/kernel/asm-offsets.c > +++ b/arch/x86/kernel/asm-offsets.c > @@ -30,7 +30,6 @@ > void common(void) { > BLANK(); > OFFSET(TI_flags, thread_info, flags); > - OFFSET(TI_status, thread_info, status); TI_status can be deleted. It's last users were removed in commit ee08c6bd. -- Brian Gerst
On Sun, Jun 26, 2016 at 4:55 PM, Brian Gerst <brgerst@gmail.com> wrote: > On Sun, Jun 26, 2016 at 5:55 PM, Andy Lutomirski <luto@kernel.org> wrote: >> Becuase sched.h and thread_info.h are a tangled mess, I turned >> in_compat_syscall into a macro. If we had current_thread_struct() >> or similar and we could use it from thread_info.h, then this would >> be a bit cleaner. >> >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> --- >> arch/x86/entry/common.c | 4 ++-- >> arch/x86/include/asm/processor.h | 12 ++++++++++++ >> arch/x86/include/asm/syscall.h | 23 +++++------------------ >> arch/x86/include/asm/thread_info.h | 23 ++++------------------- >> arch/x86/kernel/asm-offsets.c | 1 - >> arch/x86/kernel/fpu/init.c | 1 - >> arch/x86/kernel/process_64.c | 4 ++-- >> arch/x86/kernel/ptrace.c | 2 +- >> 8 files changed, 26 insertions(+), 44 deletions(-) >> >> diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c >> index ec138e538c44..c4150bec7982 100644 >> --- a/arch/x86/entry/common.c >> +++ b/arch/x86/entry/common.c >> @@ -271,7 +271,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) >> * syscalls. The fixup is exercised by the ptrace_syscall_32 >> * selftest. >> */ >> - ti->status &= ~TS_COMPAT; >> + current->thread.status &= ~TS_COMPAT; >> #endif >> >> user_enter(); >> @@ -369,7 +369,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) >> unsigned int nr = (unsigned int)regs->orig_ax; >> >> #ifdef CONFIG_IA32_EMULATION >> - ti->status |= TS_COMPAT; >> + current->thread.status |= TS_COMPAT; >> #endif >> >> if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) { >> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h >> index a2e20d6d01fe..a75e720f6402 100644 >> --- a/arch/x86/include/asm/processor.h >> +++ b/arch/x86/include/asm/processor.h >> @@ -388,6 +388,9 @@ struct thread_struct { >> unsigned short fsindex; >> unsigned short gsindex; >> #endif >> + >> + u32 status; /* thread synchronous flags */ >> + >> #ifdef CONFIG_X86_32 >> unsigned long ip; >> #endif >> @@ -437,6 +440,15 @@ struct thread_struct { >> }; >> >> /* >> + * Thread-synchronous status. >> + * >> + * This is different from the flags in that nobody else >> + * ever touches our thread-synchronous status, so we don't >> + * have to worry about atomic accesses. >> + */ >> +#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ >> + >> +/* >> * Set IOPL bits in EFLAGS from given mask >> */ >> static inline void native_set_iopl_mask(unsigned mask) >> diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h >> index 999b7cd2e78c..17229e7e2a1c 100644 >> --- a/arch/x86/include/asm/syscall.h >> +++ b/arch/x86/include/asm/syscall.h >> @@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task, >> * TS_COMPAT is set for 32-bit syscall entries and then >> * remains set until we return to user mode. >> */ >> - if (task_thread_info(task)->status & TS_COMPAT) >> + if (task->thread.status & TS_COMPAT) >> /* >> * Sign-extend the value so (int)-EFOO becomes (long)-EFOO >> * and will match correctly in comparisons. >> @@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task, >> unsigned long *args) >> { >> # ifdef CONFIG_IA32_EMULATION >> - if (task_thread_info(task)->status & TS_COMPAT) >> + if (task->thread.status & TS_COMPAT) >> switch (i) { >> case 0: >> if (!n--) break; >> @@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task, >> const unsigned long *args) >> { >> # ifdef CONFIG_IA32_EMULATION >> - if (task_thread_info(task)->status & TS_COMPAT) >> + if (task->thread.status & TS_COMPAT) >> switch (i) { >> case 0: >> if (!n--) break; >> @@ -234,21 +234,8 @@ static inline void syscall_set_arguments(struct task_struct *task, >> >> static inline int syscall_get_arch(void) >> { >> -#ifdef CONFIG_IA32_EMULATION >> - /* >> - * TS_COMPAT is set for 32-bit syscall entry and then >> - * remains set until we return to user mode. >> - * >> - * TIF_IA32 tasks should always have TS_COMPAT set at >> - * system call time. >> - * >> - * x32 tasks should be considered AUDIT_ARCH_X86_64. >> - */ >> - if (task_thread_info(current)->status & TS_COMPAT) >> - return AUDIT_ARCH_I386; >> -#endif >> - /* Both x32 and x86_64 are considered "64-bit". */ >> - return AUDIT_ARCH_X86_64; >> + /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ >> + return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; >> } >> #endif /* CONFIG_X86_32 */ >> >> diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h >> index b45ffdda3549..7b42c1e462ac 100644 >> --- a/arch/x86/include/asm/thread_info.h >> +++ b/arch/x86/include/asm/thread_info.h >> @@ -55,7 +55,6 @@ struct task_struct; >> struct thread_info { >> struct task_struct *task; /* main task structure */ >> __u32 flags; /* low level flags */ >> - __u32 status; /* thread synchronous flags */ >> __u32 cpu; /* current CPU */ >> }; >> >> @@ -211,28 +210,14 @@ static inline unsigned long current_stack_pointer(void) >> >> #endif >> >> -/* >> - * Thread-synchronous status. >> - * >> - * This is different from the flags in that nobody else >> - * ever touches our thread-synchronous status, so we don't >> - * have to worry about atomic accesses. >> - */ >> -#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ >> - >> #ifndef __ASSEMBLY__ >> >> -static inline bool in_ia32_syscall(void) >> -{ >> #ifdef CONFIG_X86_32 >> - return true; >> -#endif >> -#ifdef CONFIG_IA32_EMULATION >> - if (current_thread_info()->status & TS_COMPAT) >> - return true; >> +#define in_ia32_syscall() true >> +#else >> +#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \ >> + current->thread.status & TS_COMPAT) >> #endif >> - return false; >> -} >> >> /* >> * Force syscall return via IRET by making it look as if there was >> diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c >> index 2bd5c6ff7ee7..a91a6ead24a2 100644 >> --- a/arch/x86/kernel/asm-offsets.c >> +++ b/arch/x86/kernel/asm-offsets.c >> @@ -30,7 +30,6 @@ >> void common(void) { >> BLANK(); >> OFFSET(TI_flags, thread_info, flags); >> - OFFSET(TI_status, thread_info, status); > > TI_status can be deleted. It's last users were removed in commit ee08c6bd. Indeed. Just to double-check: are you saying that this patch is okay? --Andy
On Sun, Jun 26, 2016 at 8:23 PM, Andy Lutomirski <luto@amacapital.net> wrote: > On Sun, Jun 26, 2016 at 4:55 PM, Brian Gerst <brgerst@gmail.com> wrote: >> On Sun, Jun 26, 2016 at 5:55 PM, Andy Lutomirski <luto@kernel.org> wrote: >>> Becuase sched.h and thread_info.h are a tangled mess, I turned >>> in_compat_syscall into a macro. If we had current_thread_struct() >>> or similar and we could use it from thread_info.h, then this would >>> be a bit cleaner. >>> >>> Signed-off-by: Andy Lutomirski <luto@kernel.org> >>> --- >>> arch/x86/entry/common.c | 4 ++-- >>> arch/x86/include/asm/processor.h | 12 ++++++++++++ >>> arch/x86/include/asm/syscall.h | 23 +++++------------------ >>> arch/x86/include/asm/thread_info.h | 23 ++++------------------- >>> arch/x86/kernel/asm-offsets.c | 1 - >>> arch/x86/kernel/fpu/init.c | 1 - >>> arch/x86/kernel/process_64.c | 4 ++-- >>> arch/x86/kernel/ptrace.c | 2 +- >>> 8 files changed, 26 insertions(+), 44 deletions(-) >>> >>> diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c >>> index ec138e538c44..c4150bec7982 100644 >>> --- a/arch/x86/entry/common.c >>> +++ b/arch/x86/entry/common.c >>> @@ -271,7 +271,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) >>> * syscalls. The fixup is exercised by the ptrace_syscall_32 >>> * selftest. >>> */ >>> - ti->status &= ~TS_COMPAT; >>> + current->thread.status &= ~TS_COMPAT; >>> #endif >>> >>> user_enter(); >>> @@ -369,7 +369,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) >>> unsigned int nr = (unsigned int)regs->orig_ax; >>> >>> #ifdef CONFIG_IA32_EMULATION >>> - ti->status |= TS_COMPAT; >>> + current->thread.status |= TS_COMPAT; >>> #endif >>> >>> if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) { >>> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h >>> index a2e20d6d01fe..a75e720f6402 100644 >>> --- a/arch/x86/include/asm/processor.h >>> +++ b/arch/x86/include/asm/processor.h >>> @@ -388,6 +388,9 @@ struct thread_struct { >>> unsigned short fsindex; >>> unsigned short gsindex; >>> #endif >>> + >>> + u32 status; /* thread synchronous flags */ >>> + >>> #ifdef CONFIG_X86_32 >>> unsigned long ip; >>> #endif >>> @@ -437,6 +440,15 @@ struct thread_struct { >>> }; >>> >>> /* >>> + * Thread-synchronous status. >>> + * >>> + * This is different from the flags in that nobody else >>> + * ever touches our thread-synchronous status, so we don't >>> + * have to worry about atomic accesses. >>> + */ >>> +#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ >>> + >>> +/* >>> * Set IOPL bits in EFLAGS from given mask >>> */ >>> static inline void native_set_iopl_mask(unsigned mask) >>> diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h >>> index 999b7cd2e78c..17229e7e2a1c 100644 >>> --- a/arch/x86/include/asm/syscall.h >>> +++ b/arch/x86/include/asm/syscall.h >>> @@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task, >>> * TS_COMPAT is set for 32-bit syscall entries and then >>> * remains set until we return to user mode. >>> */ >>> - if (task_thread_info(task)->status & TS_COMPAT) >>> + if (task->thread.status & TS_COMPAT) >>> /* >>> * Sign-extend the value so (int)-EFOO becomes (long)-EFOO >>> * and will match correctly in comparisons. >>> @@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task, >>> unsigned long *args) >>> { >>> # ifdef CONFIG_IA32_EMULATION >>> - if (task_thread_info(task)->status & TS_COMPAT) >>> + if (task->thread.status & TS_COMPAT) >>> switch (i) { >>> case 0: >>> if (!n--) break; >>> @@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task, >>> const unsigned long *args) >>> { >>> # ifdef CONFIG_IA32_EMULATION >>> - if (task_thread_info(task)->status & TS_COMPAT) >>> + if (task->thread.status & TS_COMPAT) >>> switch (i) { >>> case 0: >>> if (!n--) break; >>> @@ -234,21 +234,8 @@ static inline void syscall_set_arguments(struct task_struct *task, >>> >>> static inline int syscall_get_arch(void) >>> { >>> -#ifdef CONFIG_IA32_EMULATION >>> - /* >>> - * TS_COMPAT is set for 32-bit syscall entry and then >>> - * remains set until we return to user mode. >>> - * >>> - * TIF_IA32 tasks should always have TS_COMPAT set at >>> - * system call time. >>> - * >>> - * x32 tasks should be considered AUDIT_ARCH_X86_64. >>> - */ >>> - if (task_thread_info(current)->status & TS_COMPAT) >>> - return AUDIT_ARCH_I386; >>> -#endif >>> - /* Both x32 and x86_64 are considered "64-bit". */ >>> - return AUDIT_ARCH_X86_64; >>> + /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ >>> + return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; >>> } >>> #endif /* CONFIG_X86_32 */ >>> >>> diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h >>> index b45ffdda3549..7b42c1e462ac 100644 >>> --- a/arch/x86/include/asm/thread_info.h >>> +++ b/arch/x86/include/asm/thread_info.h >>> @@ -55,7 +55,6 @@ struct task_struct; >>> struct thread_info { >>> struct task_struct *task; /* main task structure */ >>> __u32 flags; /* low level flags */ >>> - __u32 status; /* thread synchronous flags */ >>> __u32 cpu; /* current CPU */ >>> }; >>> >>> @@ -211,28 +210,14 @@ static inline unsigned long current_stack_pointer(void) >>> >>> #endif >>> >>> -/* >>> - * Thread-synchronous status. >>> - * >>> - * This is different from the flags in that nobody else >>> - * ever touches our thread-synchronous status, so we don't >>> - * have to worry about atomic accesses. >>> - */ >>> -#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ >>> - >>> #ifndef __ASSEMBLY__ >>> >>> -static inline bool in_ia32_syscall(void) >>> -{ >>> #ifdef CONFIG_X86_32 >>> - return true; >>> -#endif >>> -#ifdef CONFIG_IA32_EMULATION >>> - if (current_thread_info()->status & TS_COMPAT) >>> - return true; >>> +#define in_ia32_syscall() true >>> +#else >>> +#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \ >>> + current->thread.status & TS_COMPAT) >>> #endif >>> - return false; >>> -} >>> >>> /* >>> * Force syscall return via IRET by making it look as if there was >>> diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c >>> index 2bd5c6ff7ee7..a91a6ead24a2 100644 >>> --- a/arch/x86/kernel/asm-offsets.c >>> +++ b/arch/x86/kernel/asm-offsets.c >>> @@ -30,7 +30,6 @@ >>> void common(void) { >>> BLANK(); >>> OFFSET(TI_flags, thread_info, flags); >>> - OFFSET(TI_status, thread_info, status); >> >> TI_status can be deleted. It's last users were removed in commit ee08c6bd. > > Indeed. > > Just to double-check: are you saying that this patch is okay? It looks OK to me, but I haven't tested it. Another suggestion is to change the compat flag to a bitfield, since there is only one TS_* flag now and it's not referenced from asm. -- Brian Gerst
On Sun, Jun 26, 2016 at 5:36 PM, Brian Gerst <brgerst@gmail.com> wrote: > On Sun, Jun 26, 2016 at 8:23 PM, Andy Lutomirski <luto@amacapital.net> wrote: >> On Sun, Jun 26, 2016 at 4:55 PM, Brian Gerst <brgerst@gmail.com> wrote: >>> On Sun, Jun 26, 2016 at 5:55 PM, Andy Lutomirski <luto@kernel.org> wrote: >>>> --- a/arch/x86/kernel/asm-offsets.c >>>> +++ b/arch/x86/kernel/asm-offsets.c >>>> @@ -30,7 +30,6 @@ >>>> void common(void) { >>>> BLANK(); >>>> OFFSET(TI_flags, thread_info, flags); >>>> - OFFSET(TI_status, thread_info, status); >>> >>> TI_status can be deleted. It's last users were removed in commit ee08c6bd. >> >> Indeed. >> >> Just to double-check: are you saying that this patch is okay? > > It looks OK to me, but I haven't tested it. Another suggestion is to > change the compat flag to a bitfield, since there is only one TS_* > flag now and it's not referenced from asm. That could also work. As a silly alternative thought: we just might be able to get away with shoving the "is ia32" flag into one of the high bits of pt_regs->orig_ax. It wouldn't break any 32-bit ptrace users because they can't see the high bits. It wouldn't break most 64-bit ptrace users because they use the silly PTRACE_GETREGSET API that doesn't show the high bits if the tracee is "32-bit". It would change behavior when a 64-bit tracer traces a 64-bit process that does int $0x80, but at least strace already gets that case completely wrong. Of course, this proposal has all kinds of problems. --Andy
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index ec138e538c44..c4150bec7982 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -271,7 +271,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) * syscalls. The fixup is exercised by the ptrace_syscall_32 * selftest. */ - ti->status &= ~TS_COMPAT; + current->thread.status &= ~TS_COMPAT; #endif user_enter(); @@ -369,7 +369,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) unsigned int nr = (unsigned int)regs->orig_ax; #ifdef CONFIG_IA32_EMULATION - ti->status |= TS_COMPAT; + current->thread.status |= TS_COMPAT; #endif if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) { diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index a2e20d6d01fe..a75e720f6402 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -388,6 +388,9 @@ struct thread_struct { unsigned short fsindex; unsigned short gsindex; #endif + + u32 status; /* thread synchronous flags */ + #ifdef CONFIG_X86_32 unsigned long ip; #endif @@ -437,6 +440,15 @@ struct thread_struct { }; /* + * Thread-synchronous status. + * + * This is different from the flags in that nobody else + * ever touches our thread-synchronous status, so we don't + * have to worry about atomic accesses. + */ +#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ + +/* * Set IOPL bits in EFLAGS from given mask */ static inline void native_set_iopl_mask(unsigned mask) diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index 999b7cd2e78c..17229e7e2a1c 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task, * TS_COMPAT is set for 32-bit syscall entries and then * remains set until we return to user mode. */ - if (task_thread_info(task)->status & TS_COMPAT) + if (task->thread.status & TS_COMPAT) /* * Sign-extend the value so (int)-EFOO becomes (long)-EFOO * and will match correctly in comparisons. @@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task, unsigned long *args) { # ifdef CONFIG_IA32_EMULATION - if (task_thread_info(task)->status & TS_COMPAT) + if (task->thread.status & TS_COMPAT) switch (i) { case 0: if (!n--) break; @@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task, const unsigned long *args) { # ifdef CONFIG_IA32_EMULATION - if (task_thread_info(task)->status & TS_COMPAT) + if (task->thread.status & TS_COMPAT) switch (i) { case 0: if (!n--) break; @@ -234,21 +234,8 @@ static inline void syscall_set_arguments(struct task_struct *task, static inline int syscall_get_arch(void) { -#ifdef CONFIG_IA32_EMULATION - /* - * TS_COMPAT is set for 32-bit syscall entry and then - * remains set until we return to user mode. - * - * TIF_IA32 tasks should always have TS_COMPAT set at - * system call time. - * - * x32 tasks should be considered AUDIT_ARCH_X86_64. - */ - if (task_thread_info(current)->status & TS_COMPAT) - return AUDIT_ARCH_I386; -#endif - /* Both x32 and x86_64 are considered "64-bit". */ - return AUDIT_ARCH_X86_64; + /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ + return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; } #endif /* CONFIG_X86_32 */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index b45ffdda3549..7b42c1e462ac 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -55,7 +55,6 @@ struct task_struct; struct thread_info { struct task_struct *task; /* main task structure */ __u32 flags; /* low level flags */ - __u32 status; /* thread synchronous flags */ __u32 cpu; /* current CPU */ }; @@ -211,28 +210,14 @@ static inline unsigned long current_stack_pointer(void) #endif -/* - * Thread-synchronous status. - * - * This is different from the flags in that nobody else - * ever touches our thread-synchronous status, so we don't - * have to worry about atomic accesses. - */ -#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ - #ifndef __ASSEMBLY__ -static inline bool in_ia32_syscall(void) -{ #ifdef CONFIG_X86_32 - return true; -#endif -#ifdef CONFIG_IA32_EMULATION - if (current_thread_info()->status & TS_COMPAT) - return true; +#define in_ia32_syscall() true +#else +#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \ + current->thread.status & TS_COMPAT) #endif - return false; -} /* * Force syscall return via IRET by making it look as if there was diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 2bd5c6ff7ee7..a91a6ead24a2 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -30,7 +30,6 @@ void common(void) { BLANK(); OFFSET(TI_flags, thread_info, flags); - OFFSET(TI_status, thread_info, status); BLANK(); OFFSET(TASK_addr_limit, task_struct, thread.addr_limit); diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index aacfd7a82cec..4579c1544ed1 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -327,7 +327,6 @@ static void __init fpu__init_system_ctx_switch(void) on_boot_cpu = 0; WARN_ON_FPU(current->thread.fpu.fpstate_active); - current_thread_info()->status = 0; if (boot_cpu_has(X86_FEATURE_XSAVEOPT) && eagerfpu != DISABLE) eagerfpu = ENABLE; diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 6e789ca1f841..e6d53b641ef0 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -511,7 +511,7 @@ void set_personality_ia32(bool x32) current->personality &= ~READ_IMPLIES_EXEC; /* in_compat_syscall() uses the presence of the x32 syscall bit flag to determine compat status */ - current_thread_info()->status &= ~TS_COMPAT; + current->thread.status &= ~TS_COMPAT; } else { set_thread_flag(TIF_IA32); clear_thread_flag(TIF_X32); @@ -519,7 +519,7 @@ void set_personality_ia32(bool x32) current->mm->context.ia32_compat = TIF_IA32; current->personality |= force_personality32; /* Prepare the first "return" to user space */ - current_thread_info()->status |= TS_COMPAT; + current->thread.status |= TS_COMPAT; } } EXPORT_SYMBOL_GPL(set_personality_ia32); diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 600edd225e81..4f03301ecfbe 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -931,7 +931,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value) */ regs->orig_ax = value; if (syscall_get_nr(child, regs) >= 0) - task_thread_info(child)->status |= TS_COMPAT; + child->thread.status |= TS_COMPAT; break; case offsetof(struct user32, regs.eflags):
Becuase sched.h and thread_info.h are a tangled mess, I turned in_compat_syscall into a macro. If we had current_thread_struct() or similar and we could use it from thread_info.h, then this would be a bit cleaner. Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/entry/common.c | 4 ++-- arch/x86/include/asm/processor.h | 12 ++++++++++++ arch/x86/include/asm/syscall.h | 23 +++++------------------ arch/x86/include/asm/thread_info.h | 23 ++++------------------- arch/x86/kernel/asm-offsets.c | 1 - arch/x86/kernel/fpu/init.c | 1 - arch/x86/kernel/process_64.c | 4 ++-- arch/x86/kernel/ptrace.c | 2 +- 8 files changed, 26 insertions(+), 44 deletions(-)