* [PATCH] Linux: Use faccessat2 to implement faccessat (bug 18683)
@ 2020-08-07 16:58 Florian Weimer via Libc-alpha
2020-08-07 19:58 ` Adhemerval Zanella via Libc-alpha
0 siblings, 1 reply; 2+ messages in thread
From: Florian Weimer via Libc-alpha @ 2020-08-07 16:58 UTC (permalink / raw)
To: libc-alpha
This provides correct AT_EACCESS handling and also takes
Linux security modules into account.
Tested on i686-linux-gnu, x86_64-linux-gnu. Built with
build-many-glibcs.py.
---
sysdeps/unix/sysv/linux/faccessat.c | 14 +++++++++++---
sysdeps/unix/sysv/linux/kernel-features.h | 8 ++++++++
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/faccessat.c b/sysdeps/unix/sysv/linux/faccessat.c
index e4f18ab2db..56cb6dcc8b 100644
--- a/sysdeps/unix/sysv/linux/faccessat.c
+++ b/sysdeps/unix/sysv/linux/faccessat.c
@@ -30,6 +30,13 @@
int
faccessat (int fd, const char *file, int mode, int flag)
{
+ int ret = INLINE_SYSCALL_CALL (faccessat2, fd, file, mode, flag);
+#if __ASSUME_FACCESSAT2
+ return ret;
+#else
+ if (ret == 0 || errno != ENOSYS)
+ return ret;
+
if (flag & ~(AT_SYMLINK_NOFOLLOW | AT_EACCESS))
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
@@ -41,9 +48,9 @@ faccessat (int fd, const char *file, int mode, int flag)
return -1;
mode &= (X_OK | W_OK | R_OK); /* Clear any bogus bits. */
-#if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
-# error Oops, portability assumptions incorrect.
-#endif
+# if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
+# error Oops, portability assumptions incorrect.
+# endif
if (mode == F_OK)
return 0; /* The file exists. */
@@ -68,4 +75,5 @@ faccessat (int fd, const char *file, int mode, int flag)
return 0;
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES);
+#endif /* !__ASSUME_FACCESSAT2 */
}
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 32533e94cf..a6bbc3c94e 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -214,4 +214,12 @@
# define __ASSUME_WAITID_PID0_P_PGID
#endif
+/* The faccessat2 system call was introduced across all architectures
+ in Linux 5.8. */
+#if __LINUX_KERNEL_VERSION >= 0x050800
+# define __ASSUME_FACCESSAT2 1
+#else
+# define __ASSUME_FACCESSAT2 0
+#endif
+
#endif /* kernel-features.h */
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] Linux: Use faccessat2 to implement faccessat (bug 18683)
2020-08-07 16:58 [PATCH] Linux: Use faccessat2 to implement faccessat (bug 18683) Florian Weimer via Libc-alpha
@ 2020-08-07 19:58 ` Adhemerval Zanella via Libc-alpha
0 siblings, 0 replies; 2+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2020-08-07 19:58 UTC (permalink / raw)
To: libc-alpha
On 07/08/2020 13:58, Florian Weimer via Libc-alpha wrote:
> This provides correct AT_EACCESS handling and also takes
> Linux security modules into account.
>
> Tested on i686-linux-gnu, x86_64-linux-gnu. Built with
> build-many-glibcs.py.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>
> ---
> sysdeps/unix/sysv/linux/faccessat.c | 14 +++++++++++---
> sysdeps/unix/sysv/linux/kernel-features.h | 8 ++++++++
> 2 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/faccessat.c b/sysdeps/unix/sysv/linux/faccessat.c
> index e4f18ab2db..56cb6dcc8b 100644
> --- a/sysdeps/unix/sysv/linux/faccessat.c
> +++ b/sysdeps/unix/sysv/linux/faccessat.c
> @@ -30,6 +30,13 @@
> int
> faccessat (int fd, const char *file, int mode, int flag)
> {
> + int ret = INLINE_SYSCALL_CALL (faccessat2, fd, file, mode, flag);
> +#if __ASSUME_FACCESSAT2
> + return ret;
> +#else
> + if (ret == 0 || errno != ENOSYS)
> + return ret;
> +
> if (flag & ~(AT_SYMLINK_NOFOLLOW | AT_EACCESS))
> return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
>
Ok.
> @@ -41,9 +48,9 @@ faccessat (int fd, const char *file, int mode, int flag)
> return -1;
>
> mode &= (X_OK | W_OK | R_OK); /* Clear any bogus bits. */
> -#if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
> -# error Oops, portability assumptions incorrect.
> -#endif
> +# if R_OK != S_IROTH || W_OK != S_IWOTH || X_OK != S_IXOTH
> +# error Oops, portability assumptions incorrect.
> +# endif
>
> if (mode == F_OK)
> return 0; /* The file exists. */
Ok.
> @@ -68,4 +75,5 @@ faccessat (int fd, const char *file, int mode, int flag)
> return 0;
>
> return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES);
> +#endif /* !__ASSUME_FACCESSAT2 */
> }
Ok.
> diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
> index 32533e94cf..a6bbc3c94e 100644
> --- a/sysdeps/unix/sysv/linux/kernel-features.h
> +++ b/sysdeps/unix/sysv/linux/kernel-features.h
> @@ -214,4 +214,12 @@
> # define __ASSUME_WAITID_PID0_P_PGID
> #endif
>
> +/* The faccessat2 system call was introduced across all architectures
> + in Linux 5.8. */
> +#if __LINUX_KERNEL_VERSION >= 0x050800
> +# define __ASSUME_FACCESSAT2 1
> +#else
> +# define __ASSUME_FACCESSAT2 0
> +#endif
> +
> #endif /* kernel-features.h */
>
Ok.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-08-07 16:58 [PATCH] Linux: Use faccessat2 to implement faccessat (bug 18683) Florian Weimer via Libc-alpha
2020-08-07 19:58 ` Adhemerval Zanella via Libc-alpha
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