| Message ID | 20220524001637.1707472-20-madvenka@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: livepatch: Use ORC for dynamic frame pointer validation | expand |
Hi, sorry for the late reply... On Mon, 23 May 2022, madvenka@linux.microsoft.com wrote: > From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> > > - Create arch/arm64/include/asm/livepatch.h and define > klp_arch_set_pc() and klp_get_ftrace_location() which > are required for livepatch. > > - Define TIF_PATCH_PENDING in arch/arm64/include/asm/thread_info.h > for livepatch. > > - Check TIF_PATCH_PENDING in do_notify_resume() to patch the > current task for livepatch. > > Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> > Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com> > --- > arch/arm64/include/asm/livepatch.h | 42 ++++++++++++++++++++++++++++ > arch/arm64/include/asm/thread_info.h | 4 ++- > arch/arm64/kernel/signal.c | 4 +++ > 3 files changed, 49 insertions(+), 1 deletion(-) > create mode 100644 arch/arm64/include/asm/livepatch.h > > diff --git a/arch/arm64/include/asm/livepatch.h b/arch/arm64/include/asm/livepatch.h > new file mode 100644 > index 000000000000..72d7cd86f158 > --- /dev/null > +++ b/arch/arm64/include/asm/livepatch.h > @@ -0,0 +1,42 @@ > +/* SPDX-License-Identifier: GPL-2.0 > + * > + * livepatch.h - arm64-specific Kernel Live Patching Core > + */ > +#ifndef _ASM_ARM64_LIVEPATCH_H > +#define _ASM_ARM64_LIVEPATCH_H > + > +#include <linux/ftrace.h> > + > +static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip) > +{ > + struct pt_regs *regs = ftrace_get_regs(fregs); > + > + regs->pc = ip; > +} kernel/livepatch/ does not use klp_arch_set_pc() anymore. It was replaced by ftrace_instruction_pointer_set() and CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. > +/* > + * klp_get_ftrace_location is expected to return the address of the BL to the > + * relevant ftrace handler in the callsite. The location of this can vary based > + * on several compilation options. > + * CONFIG_DYNAMIC_FTRACE_WITH_REGS > + * - Inserts 2 nops on function entry the second of which is the BL > + * referenced above. (See ftrace_init_nop() for the callsite sequence) > + * (this is required by livepatch and must be selected) > + * CONFIG_ARM64_BTI_KERNEL: > + * - Inserts a hint #0x22 on function entry if the function is called > + * indirectly (to satisfy BTI requirements), which is inserted before > + * the two nops from above. > + */ > +#define klp_get_ftrace_location klp_get_ftrace_location > +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) > +{ > + unsigned long addr = faddr + AARCH64_INSN_SIZE; > + > +#if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) > + addr = ftrace_location_range(addr, addr + AARCH64_INSN_SIZE); > +#endif > + > + return addr; > +} This is not needed either. peterz improved the ftrace code and livepatch now uses ftrace_location() which gives the proper location directly. > diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h > index e1317b7c4525..a1d8999dbdcc 100644 > --- a/arch/arm64/include/asm/thread_info.h > +++ b/arch/arm64/include/asm/thread_info.h > @@ -68,6 +68,7 @@ int arch_dup_task_struct(struct task_struct *dst, > #define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ > #define TIF_MTE_ASYNC_FAULT 5 /* MTE Asynchronous Tag Check Fault */ > #define TIF_NOTIFY_SIGNAL 6 /* signal notifications exist */ > +#define TIF_PATCH_PENDING 7 /* pending live patching update */ > #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ > #define TIF_SYSCALL_AUDIT 9 /* syscall auditing */ > #define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */ > @@ -98,11 +99,12 @@ int arch_dup_task_struct(struct task_struct *dst, > #define _TIF_SVE (1 << TIF_SVE) > #define _TIF_MTE_ASYNC_FAULT (1 << TIF_MTE_ASYNC_FAULT) > #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) > +#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING) > > #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ > _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ > _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \ > - _TIF_NOTIFY_SIGNAL) > + _TIF_NOTIFY_SIGNAL | _TIF_PATCH_PENDING) > > #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ > _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ > diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c > index 4a4122ef6f39..cbec9597349f 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -17,6 +17,7 @@ > #include <linux/sizes.h> > #include <linux/string.h> > #include <linux/resume_user_mode.h> > +#include <linux/livepatch.h> > #include <linux/ratelimit.h> > #include <linux/syscalls.h> > > @@ -938,6 +939,9 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags) > (void __user *)NULL, current); > } > > + if (thread_flags & _TIF_PATCH_PENDING) > + klp_update_patch_state(current); > + > if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) > do_signal(regs); The rest should be fine. Regards Miroslav
Thanks for the review. On 7/1/22 09:16, Miroslav Benes wrote: > Hi, > > sorry for the late reply... > > On Mon, 23 May 2022, madvenka@linux.microsoft.com wrote: > >> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> >> >> - Create arch/arm64/include/asm/livepatch.h and define >> klp_arch_set_pc() and klp_get_ftrace_location() which >> are required for livepatch. >> >> - Define TIF_PATCH_PENDING in arch/arm64/include/asm/thread_info.h >> for livepatch. >> >> - Check TIF_PATCH_PENDING in do_notify_resume() to patch the >> current task for livepatch. >> >> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> >> Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com> >> --- >> arch/arm64/include/asm/livepatch.h | 42 ++++++++++++++++++++++++++++ >> arch/arm64/include/asm/thread_info.h | 4 ++- >> arch/arm64/kernel/signal.c | 4 +++ >> 3 files changed, 49 insertions(+), 1 deletion(-) >> create mode 100644 arch/arm64/include/asm/livepatch.h >> >> diff --git a/arch/arm64/include/asm/livepatch.h b/arch/arm64/include/asm/livepatch.h >> new file mode 100644 >> index 000000000000..72d7cd86f158 >> --- /dev/null >> +++ b/arch/arm64/include/asm/livepatch.h >> @@ -0,0 +1,42 @@ >> +/* SPDX-License-Identifier: GPL-2.0 >> + * >> + * livepatch.h - arm64-specific Kernel Live Patching Core >> + */ >> +#ifndef _ASM_ARM64_LIVEPATCH_H >> +#define _ASM_ARM64_LIVEPATCH_H >> + >> +#include <linux/ftrace.h> >> + >> +static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip) >> +{ >> + struct pt_regs *regs = ftrace_get_regs(fregs); >> + >> + regs->pc = ip; >> +} > > kernel/livepatch/ does not use klp_arch_set_pc() anymore. It was replaced > by ftrace_instruction_pointer_set() and > CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. > OK. I will address this in the next version. Thanks for pointing it out. >> +/* >> + * klp_get_ftrace_location is expected to return the address of the BL to the >> + * relevant ftrace handler in the callsite. The location of this can vary based >> + * on several compilation options. >> + * CONFIG_DYNAMIC_FTRACE_WITH_REGS >> + * - Inserts 2 nops on function entry the second of which is the BL >> + * referenced above. (See ftrace_init_nop() for the callsite sequence) >> + * (this is required by livepatch and must be selected) >> + * CONFIG_ARM64_BTI_KERNEL: >> + * - Inserts a hint #0x22 on function entry if the function is called >> + * indirectly (to satisfy BTI requirements), which is inserted before >> + * the two nops from above. >> + */ >> +#define klp_get_ftrace_location klp_get_ftrace_location >> +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) >> +{ >> + unsigned long addr = faddr + AARCH64_INSN_SIZE; >> + >> +#if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) >> + addr = ftrace_location_range(addr, addr + AARCH64_INSN_SIZE); >> +#endif >> + >> + return addr; >> +} > > This is not needed either. peterz improved the ftrace code and livepatch > now uses ftrace_location() which gives the proper location directly. > OK. I will remove this in the next version. >> diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h >> index e1317b7c4525..a1d8999dbdcc 100644 >> --- a/arch/arm64/include/asm/thread_info.h >> +++ b/arch/arm64/include/asm/thread_info.h >> @@ -68,6 +68,7 @@ int arch_dup_task_struct(struct task_struct *dst, >> #define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ >> #define TIF_MTE_ASYNC_FAULT 5 /* MTE Asynchronous Tag Check Fault */ >> #define TIF_NOTIFY_SIGNAL 6 /* signal notifications exist */ >> +#define TIF_PATCH_PENDING 7 /* pending live patching update */ >> #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ >> #define TIF_SYSCALL_AUDIT 9 /* syscall auditing */ >> #define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */ >> @@ -98,11 +99,12 @@ int arch_dup_task_struct(struct task_struct *dst, >> #define _TIF_SVE (1 << TIF_SVE) >> #define _TIF_MTE_ASYNC_FAULT (1 << TIF_MTE_ASYNC_FAULT) >> #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) >> +#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING) >> >> #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ >> _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ >> _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \ >> - _TIF_NOTIFY_SIGNAL) >> + _TIF_NOTIFY_SIGNAL | _TIF_PATCH_PENDING) >> >> #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ >> _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ >> diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c >> index 4a4122ef6f39..cbec9597349f 100644 >> --- a/arch/arm64/kernel/signal.c >> +++ b/arch/arm64/kernel/signal.c >> @@ -17,6 +17,7 @@ >> #include <linux/sizes.h> >> #include <linux/string.h> >> #include <linux/resume_user_mode.h> >> +#include <linux/livepatch.h> >> #include <linux/ratelimit.h> >> #include <linux/syscalls.h> >> >> @@ -938,6 +939,9 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags) >> (void __user *)NULL, current); >> } >> >> + if (thread_flags & _TIF_PATCH_PENDING) >> + klp_update_patch_state(current); >> + >> if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) >> do_signal(regs); > > The rest should be fine. > Thanks! Madhavan
diff --git a/arch/arm64/include/asm/livepatch.h b/arch/arm64/include/asm/livepatch.h new file mode 100644 index 000000000000..72d7cd86f158 --- /dev/null +++ b/arch/arm64/include/asm/livepatch.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * livepatch.h - arm64-specific Kernel Live Patching Core + */ +#ifndef _ASM_ARM64_LIVEPATCH_H +#define _ASM_ARM64_LIVEPATCH_H + +#include <linux/ftrace.h> + +static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip) +{ + struct pt_regs *regs = ftrace_get_regs(fregs); + + regs->pc = ip; +} + +/* + * klp_get_ftrace_location is expected to return the address of the BL to the + * relevant ftrace handler in the callsite. The location of this can vary based + * on several compilation options. + * CONFIG_DYNAMIC_FTRACE_WITH_REGS + * - Inserts 2 nops on function entry the second of which is the BL + * referenced above. (See ftrace_init_nop() for the callsite sequence) + * (this is required by livepatch and must be selected) + * CONFIG_ARM64_BTI_KERNEL: + * - Inserts a hint #0x22 on function entry if the function is called + * indirectly (to satisfy BTI requirements), which is inserted before + * the two nops from above. + */ +#define klp_get_ftrace_location klp_get_ftrace_location +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) +{ + unsigned long addr = faddr + AARCH64_INSN_SIZE; + +#if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) + addr = ftrace_location_range(addr, addr + AARCH64_INSN_SIZE); +#endif + + return addr; +} + +#endif /* _ASM_ARM64_LIVEPATCH_H */ diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index e1317b7c4525..a1d8999dbdcc 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -68,6 +68,7 @@ int arch_dup_task_struct(struct task_struct *dst, #define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ #define TIF_MTE_ASYNC_FAULT 5 /* MTE Asynchronous Tag Check Fault */ #define TIF_NOTIFY_SIGNAL 6 /* signal notifications exist */ +#define TIF_PATCH_PENDING 7 /* pending live patching update */ #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ #define TIF_SYSCALL_AUDIT 9 /* syscall auditing */ #define TIF_SYSCALL_TRACEPOINT 10 /* syscall tracepoint for ftrace */ @@ -98,11 +99,12 @@ int arch_dup_task_struct(struct task_struct *dst, #define _TIF_SVE (1 << TIF_SVE) #define _TIF_MTE_ASYNC_FAULT (1 << TIF_MTE_ASYNC_FAULT) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) +#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING) #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \ - _TIF_NOTIFY_SIGNAL) + _TIF_NOTIFY_SIGNAL | _TIF_PATCH_PENDING) #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 4a4122ef6f39..cbec9597349f 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -17,6 +17,7 @@ #include <linux/sizes.h> #include <linux/string.h> #include <linux/resume_user_mode.h> +#include <linux/livepatch.h> #include <linux/ratelimit.h> #include <linux/syscalls.h> @@ -938,6 +939,9 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags) (void __user *)NULL, current); } + if (thread_flags & _TIF_PATCH_PENDING) + klp_update_patch_state(current); + if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) do_signal(regs);