[PATCH 1/2] linux-user: Show SIGCHLD in clone() strace output

[PATCH 1/2] linux-user: Show SIGCHLD in clone() strace output

[Helge Deller]

When stracing a program, show up the SIGCHLD value the same
way as it's done when running strace natively, e.g.:
clone(child_stack=0xf7af0040, flags=CLONE_VM|CLONE_VFORK|SIGCHLD, ...

Signed-off-by: Helge Deller <deller@gmx.de>
---
 linux-user/strace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 82dc1a1e20..3157e4b420 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -1136,6 +1136,7 @@ UNUSED static struct flags clone_flags[] = {
 #if defined(CLONE_IO)
     FLAG_GENERIC(CLONE_IO),
 #endif
+    FLAG_TARGET(SIGCHLD),
     FLAG_END,
 };

--
2.38.1

[PATCH 2/2] linux-user: Show 4th argument of rt_sigprocmask() in strace

[Helge Deller]

Add output for the missing 4th parameter (size_t sigsetsize).

Signed-off-by: Helge Deller <deller@gmx.de>
---
 linux-user/strace.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 3157e4b420..e3aa994678 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -3146,7 +3146,8 @@ print_rt_sigprocmask(CPUArchState *cpu_env, const struct syscallname *name,
     }
     qemu_log("%s,", how);
     print_pointer(arg1, 0);
-    print_pointer(arg2, 1);
+    print_pointer(arg2, 0);
+    print_raw_param("%d", arg3, 1);
     print_syscall_epilogue(name);
 }
 #endif
--
2.38.1

Re: [PATCH 2/2] linux-user: Show 4th argument of rt_sigprocmask() in strace

[Laurent Vivier]

Le 25/01/2023 à 14:57, Helge Deller a écrit :
> Add output for the missing 4th parameter (size_t sigsetsize).
> 
> Signed-off-by: Helge Deller <deller@gmx.de>
> ---
>   linux-user/strace.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 3157e4b420..e3aa994678 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -3146,7 +3146,8 @@ print_rt_sigprocmask(CPUArchState *cpu_env, const struct syscallname *name,
>       }
>       qemu_log("%s,", how);
>       print_pointer(arg1, 0);
> -    print_pointer(arg2, 1);
> +    print_pointer(arg2, 0);
> +    print_raw_param("%d", arg3, 1);

Better with "%u" as size_t is unsigned.

Thanks,
Laurent
>       print_syscall_epilogue(name);
>   }
>   #endif
> --
> 2.38.1
> 
> 

Re: [PATCH 1/2] linux-user: Show SIGCHLD in clone() strace output

[Helge Deller]

On 1/25/23 14:57, Helge Deller wrote:
> When stracing a program, show up the SIGCHLD value the same
> way as it's done when running strace natively, e.g.:
> clone(child_stack=0xf7af0040, flags=CLONE_VM|CLONE_VFORK|SIGCHLD, ...
>
> Signed-off-by: Helge Deller <deller@gmx.de>
> ---
>   linux-user/strace.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 82dc1a1e20..3157e4b420 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -1136,6 +1136,7 @@ UNUSED static struct flags clone_flags[] = {
>   #if defined(CLONE_IO)
>       FLAG_GENERIC(CLONE_IO),
>   #endif
> +    FLAG_TARGET(SIGCHLD),

It's actually not 100% correct, as this would trigger for other SIGxxx values too,
which have the same bits set as TARGET_SIGCHLD. Given the fact that we only support
TARGET_SIGCHLD in clone(), it would nevertheless in most cases show the correct output.

So, probably it's best to not apply this patch it as-is.

Helge