diff mbox

[v2] syscall: fixed mincore(2) not failing with ENOMEM

Message ID 20170217085800.28873-2-snaipe@diacritic.io
State New
Headers show

Commit Message

Franklin Snaipe Mathieu Feb. 17, 2017, 8:58 a.m. UTC 
From: "Franklin \"Snaipe\" Mathieu" <snaipe@diacritic.io>

The current implementation of the mincore(2) syscall sets errno to
EFAULT when the region identified by the first two parameters is
invalid.

This goes against the man page specification, where mincore(2) should
only fail with EFAULT when the third parameter is an invalid address;
and fail with ENOMEM when the checked region does not point to mapped
memory.

Signed-off-by: Franklin "Snaipe" Mathieu <snaipe@diacritic.io>
Cc: Riku Voipio <riku.voipio@linaro.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
---
 linux-user/syscall.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Laurent Vivier Feb. 26, 2017, 1:12 p.m. UTC | #1 
Le 17/02/2017 à 09:58, Franklin Snaipe Mathieu a écrit :
> From: "Franklin \"Snaipe\" Mathieu" <snaipe@diacritic.io>
> 
> The current implementation of the mincore(2) syscall sets errno to
> EFAULT when the region identified by the first two parameters is
> invalid.
> 
> This goes against the man page specification, where mincore(2) should
> only fail with EFAULT when the third parameter is an invalid address;
> and fail with ENOMEM when the checked region does not point to mapped
> memory.
> 
> Signed-off-by: Franklin "Snaipe" Mathieu <snaipe@diacritic.io>
> Cc: Riku Voipio <riku.voipio@linaro.org>
> Cc: Aurelien Jarno <aurelien@aurel32.net>
> ---
>  linux-user/syscall.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 9be8e9530e..733e0009e1 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -11061,11 +11061,16 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
>      case TARGET_NR_mincore:
>          {
>              void *a;
> +            ret = -TARGET_ENOMEM;
> +            a = lock_user(VERIFY_READ, arg1, arg2, 0);
> +            if (!a) {
> +                goto fail;
> +            }
>              ret = -TARGET_EFAULT;
> -            if (!(a = lock_user(VERIFY_READ, arg1,arg2, 0)))
> -                goto efault;
> -            if (!(p = lock_user_string(arg3)))
> +            p = lock_user_string(arg3);
> +            if (!p) {
>                  goto mincore_fail;
> +            }
>              ret = get_errno(mincore(a, arg2, p));
>              unlock_user(p, arg3, ret);
>              mincore_fail:
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
diff mbox

Patch

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 9be8e9530e..733e0009e1 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -11061,11 +11061,16 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     case TARGET_NR_mincore:
         {
             void *a;
+            ret = -TARGET_ENOMEM;
+            a = lock_user(VERIFY_READ, arg1, arg2, 0);
+            if (!a) {
+                goto fail;
+            }
             ret = -TARGET_EFAULT;
-            if (!(a = lock_user(VERIFY_READ, arg1,arg2, 0)))
-                goto efault;
-            if (!(p = lock_user_string(arg3)))
+            p = lock_user_string(arg3);
+            if (!p) {
                 goto mincore_fail;
+            }
             ret = get_errno(mincore(a, arg2, p));
             unlock_user(p, arg3, ret);
             mincore_fail: