diff options
| author | bibo,mao <bibo.mao@intel.com> | 2007-01-31 17:50:31 +0800 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2007-02-05 13:49:29 -0800 |
| commit | 90f9d70a582c02f50b4dd847166cd5b037219891 (patch) | |
| tree | ffe6b5246f9e2334b474ca0913776668803d1ea0 | |
| parent | c237508afa5d47282d3047784864013eebdc68ab (diff) | |
[IA64] enable singlestep on system call
As is pointed out in
http://www.gelato.org/community/view_linear.php?id=1_1036&from=authors&value=Ian%20Wienand#1_1039,
if single step on break instruction, the break fault has higher
priority than the single-step trap. When the break fault handler
is entered, it advances the IP by 1 instruction so break instruction
single-stepping is skipped, actually it is next instruction which
is single stepped.
This patch modifies this, it adds TIF_SINGLESTEP bit for thread
flags, and generate a fake sigtrap when single stepping break
instruction. Test case in attachment can verify this. Any comments
is welcome.
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
| -rw-r--r-- | arch/ia64/kernel/ptrace.c | 12 | ||||
| -rw-r--r-- | include/asm-ia64/thread_info.h | 4 |
2 files changed, 9 insertions, 7 deletions
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index aa705e46b974..f1ec129ae3a1 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1405,6 +1405,7 @@ ptrace_disable (struct task_struct *child) struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child)); /* make sure the single step/taken-branch trap bits are not set: */ + clear_tsk_thread_flag(child, TIF_SINGLESTEP); child_psr->ss = 0; child_psr->tb = 0; } @@ -1525,6 +1526,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) * Make sure the single step/taken-branch trap bits * are not set: */ + clear_tsk_thread_flag(child, TIF_SINGLESTEP); ia64_psr(pt)->ss = 0; ia64_psr(pt)->tb = 0; @@ -1556,6 +1558,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) goto out_tsk; clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + set_tsk_thread_flag(child, TIF_SINGLESTEP); if (request == PTRACE_SINGLESTEP) { ia64_psr(pt)->ss = 1; } else { @@ -1595,13 +1598,9 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) } -void +static void syscall_trace (void) { - if (!test_thread_flag(TIF_SYSCALL_TRACE)) - return; - if (!(current->ptrace & PT_PTRACED)) - return; /* * The 0x80 provides a way for the tracing parent to * distinguish between a syscall stop and SIGTRAP delivery. @@ -1664,7 +1663,8 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3, audit_syscall_exit(success, result); } - if (test_thread_flag(TIF_SYSCALL_TRACE) + if ((test_thread_flag(TIF_SYSCALL_TRACE) + || test_thread_flag(TIF_SINGLESTEP)) && (current->ptrace & PT_PTRACED)) syscall_trace(); } diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h index 9b505b25544f..91698599f918 100644 --- a/include/asm-ia64/thread_info.h +++ b/include/asm-ia64/thread_info.h @@ -84,6 +84,7 @@ struct thread_info { #define TIF_NEED_RESCHED 2 /* rescheduling necessary */ #define TIF_SYSCALL_TRACE 3 /* syscall trace active */ #define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */ +#define TIF_SINGLESTEP 5 /* restore singlestep on return to user mode */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 #define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */ @@ -92,7 +93,8 @@ struct thread_info { #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) -#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) +#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) +#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) |