ARM: support syscall tracing
Subsystems (2)
PATCH v4 1/1 ARM: support syscall tracing
As specified by ftrace-design.txt, TIF_SYSCALL_TRACEPOINT was added, as well as NR_syscalls in asm/unistd.h. Additionally, __sys_trace was modified to call trace_sys_enter and trace_sys_exit when appropriate.
Tests #2 - #4 of "perf test" now complete successfully.
Signed-off-by Steven Walter <[email protected]>
Signed-off-by Wade Farnsworth <[email protected]>
---
This patch is an update of one I posted some months ago. It has been rebased to Linus's current master branch.
- v2: Implemented changes suggested by Will:
- Folded _TIF_SYSCALL_TRACEPOINT into _TIF_SYSCALL_WORK to save an instruction in entry-common.S.
- Moved calls to trace_sys_{enter,exit} to syscall_trace_{enter,exit}
- v3:
- Set current_thread_info()->syscall before checking TIF_SYSCALL_TRACE.
- Pass the original syscall number into trace_sys_{enter,exit}, not the return value from ptrace_syscall_trace().
- v4: More changes based on Will's feedback:
- Reverted to passing the return value from ptrace_syscall_trace() into
trace_sys_{enter,exit}.
- Removed inadvertent whitespace change.
arch/arm/Kconfig | 1 +
arch/arm/include/asm/syscall.h | 4 ++++
arch/arm/include/asm/thread_info.h | 4 +++-
arch/arm/include/asm/unistd.h | 8 ++++++++
arch/arm/kernel/entry-common.S | 9 +++++++++
arch/arm/kernel/ptrace.c | 11 +++++++++--
6 files changed, 34 insertions(+), 3 deletions(-)arch/arm/Kconfig +1 -0
@@ -16,6 +16,7 @@ config ARM select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_KGDB select HAVE_ARCH_TRACEHOOK + select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES if !XIP_KERNEL select HAVE_KRETPROBES if (HAVE_KPROBES) select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
arch/arm/include/asm/syscall.h +4 -0
@@ -9,6 +9,10 @@#include <linux/err.h> +#include <asm/unistd.h> + +#define NR_syscalls (__NR_syscalls) +extern const unsigned long sys_call_table[]; static inline int syscall_get_nr(struct task_struct *task,
arch/arm/include/asm/thread_info.h +3 -1
@@ -148,6 +148,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,#define TIF_NOTIFY_RESUME 2/* callback before returning to user */ #define TIF_SYSCALL_TRACE 8#define TIF_SYSCALL_AUDIT 9 +#define TIF_SYSCALL_TRACEPOINT 10#define TIF_POLLING_NRFLAG 16#define TIF_USING_IWMMXT 17#define TIF_MEMDIE 18/* is terminating due to OOM killer */
@@ -160,12 +161,13 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) +#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)#define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT)#define _TIF_SECCOMP (1 << TIF_SECCOMP)/* Checks for any syscall work in entry-common.S */ -#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT) +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)/* * Change these and you break ASM code in entry-common.S
arch/arm/include/asm/unistd.h +8 -0
@@ -406,6 +406,14 @@#define __NR_process_vm_writev (__NR_SYSCALL_BASE+377)/* +* This may need to be greater than __NR_last_syscall+1 in order to +* account for the padding in the syscall table +*/ +#ifdef __KERNEL__ +#define __NR_syscalls (380) +#endif /* __KERNEL__ */ + +/* * The following SWIs are ARM private. */ #define __ARM_NR_BASE (__NR_SYSCALL_BASE+0x0f0000)
arch/arm/kernel/entry-common.S +9 -0
@@ -94,6 +94,15 @@ ENDPROC(ret_from_fork) .equ NR_syscalls,0 #define CALL(x) .equ NR_syscalls,NR_syscalls+1 #include "calls.S" + +/* + * Ensure that the system call table is equal to __NR_syscalls, + * which is the value the rest of the system sees + */ +.ifne NR_syscalls - __NR_syscalls +.error "__NR_syscalls is not equal to the size of the syscall table" +.endif + #undef CALL #define CALL(x) .long x
arch/arm/kernel/ptrace.c +9 -2
@@ -30,6 +30,9 @@#include <asm/pgtable.h> #include <asm/traps.h> +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> +#define REG_PC 15#define REG_PSR 16/*
@@ -918,11 +921,11 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, {unsigned long ip; +current_thread_info ()->syscall = scno; +if (!test_thread_flag (TIF_SYSCALL_TRACE ))return scno; -current_thread_info ()->syscall = scno; -/* * IP is used to denote syscall entry/exit: * IP = 0 -> entry, =1 -> exit
@@ -942,6 +945,8 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) {int ret =ptrace_syscall_trace (regs, scno,PTRACE_SYSCALL_ENTER ); +if (test_thread_flag (TIF_SYSCALL_TRACEPOINT )) +trace_sys_enter (regs, ret);audit_syscall_entry (AUDIT_ARCH_ARM , scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);return ret;
@@ -950,6 +955,8 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) asmlinkage int syscall_trace_exit(struct pt_regs *regs, int scno) {int ret =ptrace_syscall_trace (regs, scno,PTRACE_SYSCALL_EXIT ); +if (test_thread_flag (TIF_SYSCALL_TRACEPOINT )) +trace_sys_exit (regs, ret);audit_syscall_exit (regs);return ret; }
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1.7.0.4