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| author | Bodo Stroesser <bstroesser@fujitsu-siemens.com> | 2005-09-04 02:57:20 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 11:06:20 +0400 |
| commit | 1b38f0064e4e0b9ec626e39f0740b1cf2e295743 (patch) | |
| tree | b5e3af88b23bd47d91c4745a3e0c61512f58ff21 /arch | |
| parent | c8c86cecd1d1a2722acb28a01d1babf7b6993697 (diff) | |
| download | linux-1b38f0064e4e0b9ec626e39f0740b1cf2e295743.tar.xz | |
[PATCH] Uml support: add PTRACE_SYSEMU_SINGLESTEP option to i386
This patch implements the new ptrace option PTRACE_SYSEMU_SINGLESTEP, which
can be used by UML to singlestep a process: it will receive SINGLESTEP
interceptions for normal instructions and syscalls, but syscall execution will
be skipped just like with PTRACE_SYSEMU.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/kernel/ptrace.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index 18642f05dde1..3196ba50fcd5 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -547,11 +547,17 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) wake_up_process(child); break; + case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */ case PTRACE_SINGLESTEP: /* set the trap flag. */ ret = -EIO; if (!valid_signal(data)) break; - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); + + if (request == PTRACE_SYSEMU_SINGLESTEP) + set_tsk_thread_flag(child, TIF_SYSCALL_EMU); + else + clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); set_singlestep(child); child->exit_code = data; @@ -686,7 +692,10 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) __attribute__((regparm(3))) int do_syscall_trace(struct pt_regs *regs, int entryexit) { - int is_sysemu, is_singlestep, ret = 0; + int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU), ret = 0; + /* With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP */ + int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); + /* do the secure computing check first */ secure_computing(regs->orig_eax); @@ -696,8 +705,11 @@ int do_syscall_trace(struct pt_regs *regs, int entryexit) if (!(current->ptrace & PT_PTRACED)) goto out; - is_sysemu = test_thread_flag(TIF_SYSCALL_EMU); - is_singlestep = test_thread_flag(TIF_SINGLESTEP); + /* If a process stops on the 1st tracepoint with SYSCALL_TRACE + * and then is resumed with SYSEMU_SINGLESTEP, it will come in + * here. We have to check this and return */ + if (is_sysemu && entryexit) + return 0; /* Fake a debug trap */ if (is_singlestep) @@ -728,6 +740,7 @@ int do_syscall_trace(struct pt_regs *regs, int entryexit) if (ret == 0) return 0; + regs->orig_eax = -1; /* force skip of syscall restarting */ if (unlikely(current->audit_context)) audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax); return 1; |