Am 06.08.2012 17:37, schrieb Renzo Davoli:
> ---
> diff -Naur linux-3.6-rc1/arch/um/include/asm/ptrace-generic.h
> linux-3.6-rc1.tracehook/arch/um/include/asm/ptrace-generic.h
> --- linux-3.6-rc1/arch/um/include/asm/ptrace-generic.h 2012-08-03
> 01:38:10.000000000 +0200
> +++ linux-3.6-rc1.tracehook/arch/um/include/asm/ptrace-generic.h
> 2012-08-06 14:43:01.000000000 +0200
> @@ -37,7 +37,7 @@
>
> extern int arch_copy_tls(struct task_struct *new);
> extern void clear_flushed_tls(struct task_struct *task);
> -extern void syscall_trace_enter(struct pt_regs *regs);
> +extern int syscall_trace_enter(struct pt_regs *regs);
> extern void syscall_trace_leave(struct pt_regs *regs);
>
> #endif
> diff -Naur linux-3.6-rc1/arch/um/include/shared/kern_util.h
> linux-3.6-rc1.tracehook/arch/um/include/shared/kern_util.h
> --- linux-3.6-rc1/arch/um/include/shared/kern_util.h 2012-08-03
> 01:38:10.000000000 +0200
> +++ linux-3.6-rc1.tracehook/arch/um/include/shared/kern_util.h
> 2012-08-06 14:43:40.000000000 +0200
> @@ -57,7 +57,6 @@
> extern unsigned long to_irq_stack(unsigned long *mask_out);
> extern unsigned long from_irq_stack(int nested);
>
> -extern void syscall_trace(struct uml_pt_regs *regs, int entryexit);
> extern int singlestepping(void *t);
>
> extern void segv_handler(int sig, struct siginfo *unused_si, struct
> uml_pt_regs *regs);
> diff -Naur linux-3.6-rc1/arch/um/kernel/ptrace.c
> linux-3.6-rc1.tracehook/arch/um/kernel/ptrace.c
> --- linux-3.6-rc1/arch/um/kernel/ptrace.c 2012-08-03 01:38:10.000000000
> +0200
> +++ linux-3.6-rc1.tracehook/arch/um/kernel/ptrace.c 2012-08-06
> 14:45:07.000000000 +0200
> @@ -163,7 +163,7 @@
> * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
> * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
> */
> -void syscall_trace_enter(struct pt_regs *regs)
> +int syscall_trace_enter(struct pt_regs *regs)
> {
> audit_syscall_entry(HOST_AUDIT_ARCH,
> UPT_SYSCALL_NR(®s->regs),
> @@ -173,9 +173,9 @@
> UPT_SYSCALL_ARG4(®s->regs));
>
> if (!test_thread_flag(TIF_SYSCALL_TRACE))
> - return;
> + return 0;
>
> - tracehook_report_syscall_entry(regs);
> + return tracehook_report_syscall_entry(regs);
> }
>
> void syscall_trace_leave(struct pt_regs *regs)
> diff -Naur linux-3.6-rc1/arch/um/kernel/skas/syscall.c
> linux-3.6-rc1.tracehook/arch/um/kernel/skas/syscall.c
> --- linux-3.6-rc1/arch/um/kernel/skas/syscall.c 2012-08-03
> 01:38:10.000000000 +0200
> +++ linux-3.6-rc1.tracehook/arch/um/kernel/skas/syscall.c 2012-08-06
> 14:46:35.000000000 +0200
> @@ -18,23 +18,24 @@
> long result;
> int syscall;
>
> - syscall_trace_enter(regs);
> + if (syscall_trace_enter(regs) == 0)
> + {
> + /*
> + * This should go in the declaration of syscall, but when I do
> that,
> + * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
> + * children at all, sometimes hanging when bash doesn't see the
> first
> + * ls exit.
> + * The assembly looks functionally the same to me. This is
> + * gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
> + * in case it's a compiler bug.
> + */
> + syscall = UPT_SYSCALL_NR(r);
> + if ((syscall >= NR_SYSCALLS) || (syscall < 0))
> + result = -ENOSYS;
> + else result = EXECUTE_SYSCALL(syscall, regs);
>
> - /*
> - * This should go in the declaration of syscall, but when I do that,
> - * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
> - * children at all, sometimes hanging when bash doesn't see the first
> - * ls exit.
> - * The assembly looks functionally the same to me. This is
> - * gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
> - * in case it's a compiler bug.
> - */
> - syscall = UPT_SYSCALL_NR(r);
> - if ((syscall >= NR_SYSCALLS) || (syscall < 0))
> - result = -ENOSYS;
> - else result = EXECUTE_SYSCALL(syscall, regs);
> -
> - PT_REGS_SET_SYSCALL_RETURN(regs, result);
> + PT_REGS_SET_SYSCALL_RETURN(regs, result);
> + }
>
> syscall_trace_leave(regs);Hmm, is it a good idea to call syscall_trace_leave() in any case? E.g. if syscall_trace_enter() fails for whatever reason... Thanks, //richard
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