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author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2014-04-30 09:54:36 (GMT) |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2014-05-29 08:08:33 (GMT) |
commit | 055b1212d141f1f398fca548f8147787c0b6253f (patch) | |
tree | a2baa3bd73b450008056bf69edf708e7902736b5 | |
parent | 3711784ece66d39352a0dbb6da40e097a77da057 (diff) | |
download | linux-055b1212d141f1f398fca548f8147787c0b6253f.tar.xz |
arm64: ftrace: Add system call tracepoint
This patch allows system call entry or exit to be traced as ftrace events,
ie. sys_enter_*/sys_exit_*, if CONFIG_FTRACE_SYSCALLS is enabled.
Those events appear and can be controlled under
${sysfs}/tracing/events/syscalls/
Please note that we can't trace compat system calls here because
AArch32 mode does not share the same syscall table with AArch64.
Just define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS in order to avoid unexpected
results (bogus syscalls reported or even hang-up).
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm64/include/asm/ftrace.h | 18 | ||||
-rw-r--r-- | arch/arm64/include/asm/syscall.h | 1 | ||||
-rw-r--r-- | arch/arm64/include/asm/unistd.h | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/ptrace.c | 9 |
5 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4e689ad..bceeaf1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -48,6 +48,7 @@ config ARM64 select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN select MODULES_USE_ELF_RELA select NO_BOOTMEM diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 41e8670..c5534fa 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -17,6 +17,8 @@ #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE #ifndef __ASSEMBLY__ +#include <linux/compat.h> + extern void _mcount(unsigned long); extern void *return_address(unsigned int); @@ -36,6 +38,22 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) } #define ftrace_return_address(n) return_address(n) + +/* + * Because AArch32 mode does not share the same syscall table with AArch64, + * tracing compat syscalls may result in reporting bogus syscalls or even + * hang-up, so just do not trace them. + * See kernel/trace/trace_syscalls.c + * + * x86 code says: + * If the user realy wants these, then they should use the + * raw syscall tracepoints with filtering. + */ +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) +{ + return is_compat_task(); +} #endif /* ifndef __ASSEMBLY__ */ #endif /* __ASM_FTRACE_H */ diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index 70ba9d4..383771e 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -18,6 +18,7 @@ #include <linux/err.h> +extern const void *sys_call_table[]; static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index a4654c6..e5f47df 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -29,3 +29,5 @@ #endif #define __ARCH_WANT_SYS_CLONE #include <uapi/asm/unistd.h> + +#define NR_syscalls (__NR_syscalls) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 32d52d3..3e926b9 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -42,6 +42,9 @@ #include <asm/traps.h> #include <asm/system_misc.h> +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> + /* * TODO: does not yet catch signals sent when the child dies. * in exit.c or in signal.c. @@ -1093,11 +1096,17 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_enter(regs, regs->syscallno); + return regs->syscallno; } asmlinkage void syscall_trace_exit(struct pt_regs *regs) { + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_exit(regs, regs_return_value(regs)); + if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT); } |