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[PATCH] linux-user: fix pidfd_send_signal()

Laurent Vivier posted 1 patch 3 years, 4 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20221005163826.1455313-1-laurent@vivier.eu
Maintainers: Laurent Vivier <laurent@vivier.eu>
linux-user/strace.c  |  4 ++--
linux-user/syscall.c | 19 ++++++++++++-------
2 files changed, 14 insertions(+), 9 deletions(-)
[PATCH] linux-user: fix pidfd_send_signal()
Posted by Laurent Vivier 3 years, 4 months ago 
According to pidfd_send_signal(2), info argument can be a NULL pointer.
Fix strace to correctly manage ending comma in parameters.

Fixes: cc054c6f13 ("linux-user: Add pidfd_open(), pidfd_send_signal() and pidfd_getfd() syscalls")
cc: Helge Deller <deller@gmx.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/strace.c  |  4 ++--
 linux-user/syscall.c | 19 ++++++++++++-------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 37bc96df9bb6..86c081c83f74 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -3383,10 +3383,10 @@ print_pidfd_send_signal(CPUArchState *cpu_env, const struct syscallname *name,
 
         unlock_user(p, arg2, 0);
     } else {
-        print_pointer(arg2, 1);
+        print_pointer(arg2, 0);
     }
 
-    print_raw_param("%u", arg3, 0);
+    print_raw_param("%u", arg3, 1);
     print_syscall_epilogue(name);
 }
 #endif
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 2e954d8dbd9e..b1493917ee07 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8679,16 +8679,21 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
 #if defined(__NR_pidfd_send_signal) && defined(TARGET_NR_pidfd_send_signal)
     case TARGET_NR_pidfd_send_signal:
         {
-            siginfo_t uinfo;
+            siginfo_t uinfo, *puinfo;
 
-            p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
-            if (!p) {
-                return -TARGET_EFAULT;
+            if (arg3) {
+                p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
+                if (!p) {
+                    return -TARGET_EFAULT;
+                 }
+                 target_to_host_siginfo(&uinfo, p);
+                 unlock_user(p, arg3, 0);
+                 puinfo = &uinfo;
+            } else {
+                 puinfo = NULL;
             }
-            target_to_host_siginfo(&uinfo, p);
-            unlock_user(p, arg3, 0);
             ret = get_errno(pidfd_send_signal(arg1, target_to_host_signal(arg2),
-                &uinfo, arg4));
+                                              puinfo, arg4));
         }
         return ret;
 #endif
-- 
2.37.3
Re: [PATCH] linux-user: fix pidfd_send_signal()
Posted by Laurent Vivier 3 years, 3 months ago 
Le 05/10/2022 à 18:38, Laurent Vivier a écrit :
> According to pidfd_send_signal(2), info argument can be a NULL pointer.
> Fix strace to correctly manage ending comma in parameters.
> 
> Fixes: cc054c6f13 ("linux-user: Add pidfd_open(), pidfd_send_signal() and pidfd_getfd() syscalls")
> cc: Helge Deller <deller@gmx.de>
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>   linux-user/strace.c  |  4 ++--
>   linux-user/syscall.c | 19 ++++++++++++-------
>   2 files changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 37bc96df9bb6..86c081c83f74 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -3383,10 +3383,10 @@ print_pidfd_send_signal(CPUArchState *cpu_env, const struct syscallname *name,
>   
>           unlock_user(p, arg2, 0);
>       } else {
> -        print_pointer(arg2, 1);
> +        print_pointer(arg2, 0);
>       }
>   
> -    print_raw_param("%u", arg3, 0);
> +    print_raw_param("%u", arg3, 1);
>       print_syscall_epilogue(name);
>   }
>   #endif
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 2e954d8dbd9e..b1493917ee07 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8679,16 +8679,21 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
>   #if defined(__NR_pidfd_send_signal) && defined(TARGET_NR_pidfd_send_signal)
>       case TARGET_NR_pidfd_send_signal:
>           {
> -            siginfo_t uinfo;
> +            siginfo_t uinfo, *puinfo;
>   
> -            p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
> -            if (!p) {
> -                return -TARGET_EFAULT;
> +            if (arg3) {
> +                p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
> +                if (!p) {
> +                    return -TARGET_EFAULT;
> +                 }
> +                 target_to_host_siginfo(&uinfo, p);
> +                 unlock_user(p, arg3, 0);
> +                 puinfo = &uinfo;
> +            } else {
> +                 puinfo = NULL;
>               }
> -            target_to_host_siginfo(&uinfo, p);
> -            unlock_user(p, arg3, 0);
>               ret = get_errno(pidfd_send_signal(arg1, target_to_host_signal(arg2),
> -                &uinfo, arg4));
> +                                              puinfo, arg4));
>           }
>           return ret;
>   #endif

Applied to my linux-user-for-7.2 branch.

Thanks,
Laurent
Re: [PATCH] linux-user: fix pidfd_send_signal()
Posted by Helge Deller 3 years, 4 months ago 
On 10/5/22 18:38, Laurent Vivier wrote:
> According to pidfd_send_signal(2), info argument can be a NULL pointer.
> Fix strace to correctly manage ending comma in parameters.
>
> Fixes: cc054c6f13 ("linux-user: Add pidfd_open(), pidfd_send_signal() and pidfd_getfd() syscalls")
> cc: Helge Deller <deller@gmx.de>
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>


Reviewed-by: Helge Deller <deller@gmx.de>



> ---
>   linux-user/strace.c  |  4 ++--
>   linux-user/syscall.c | 19 ++++++++++++-------
>   2 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 37bc96df9bb6..86c081c83f74 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -3383,10 +3383,10 @@ print_pidfd_send_signal(CPUArchState *cpu_env, const struct syscallname *name,
>
>           unlock_user(p, arg2, 0);
>       } else {
> -        print_pointer(arg2, 1);
> +        print_pointer(arg2, 0);
>       }
>
> -    print_raw_param("%u", arg3, 0);
> +    print_raw_param("%u", arg3, 1);
>       print_syscall_epilogue(name);
>   }
>   #endif
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 2e954d8dbd9e..b1493917ee07 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8679,16 +8679,21 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
>   #if defined(__NR_pidfd_send_signal) && defined(TARGET_NR_pidfd_send_signal)
>       case TARGET_NR_pidfd_send_signal:
>           {
> -            siginfo_t uinfo;
> +            siginfo_t uinfo, *puinfo;
>
> -            p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
> -            if (!p) {
> -                return -TARGET_EFAULT;
> +            if (arg3) {
> +                p = lock_user(VERIFY_READ, arg3, sizeof(target_siginfo_t), 1);
> +                if (!p) {
> +                    return -TARGET_EFAULT;
> +                 }
> +                 target_to_host_siginfo(&uinfo, p);
> +                 unlock_user(p, arg3, 0);
> +                 puinfo = &uinfo;
> +            } else {
> +                 puinfo = NULL;
>               }
> -            target_to_host_siginfo(&uinfo, p);
> -            unlock_user(p, arg3, 0);
>               ret = get_errno(pidfd_send_signal(arg1, target_to_host_signal(arg2),
> -                &uinfo, arg4));
> +                                              puinfo, arg4));
>           }
>           return ret;
>   #endif

Patchew 2.1-devel-b67e4c2

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