From 7a16bdbb9ff4122af0a28dc20996c95352011fdd Mon Sep 17 00:00:00 2001
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Wed, 29 Aug 2018 16:36:44 -0300
Subject: Fix misreported errno on preadv2/pwritev2 (BZ#23579)
The fallback code of Linux wrapper for preadv2/pwritev2 executes
regardless of the errno code for preadv2, instead of the case where
the syscall is not supported.
This fixes it by calling the fallback code iff errno is ENOSYS. The
patch also adds tests for both invalid file descriptor and invalid
iov_len and vector count.
The only discrepancy between preadv2 and fallback code regarding
error reporting is when an invalid flags are used. The fallback code
bails out earlier with ENOTSUP instead of EINVAL/EBADF when the syscall
is used.
Checked on x86_64-linux-gnu on a 4.4.0 and 4.15.0 kernel.
[BZ #23579]
* misc/tst-preadvwritev2-common.c (do_test_with_invalid_fd): New
test.
* misc/tst-preadvwritev2.c, misc/tst-preadvwritev64v2.c (do_test):
Call do_test_with_invalid_fd.
* sysdeps/unix/sysv/linux/preadv2.c (preadv2): Use fallback code iff
errno is ENOSYS.
* sysdeps/unix/sysv/linux/preadv64v2.c (preadv64v2): Likewise.
* sysdeps/unix/sysv/linux/pwritev2.c (pwritev2): Likewise.
* sysdeps/unix/sysv/linux/pwritev64v2.c (pwritev64v2): Likewise.
---
sysdeps/unix/sysv/linux/preadv2.c | 2 +-
sysdeps/unix/sysv/linux/preadv64v2.c | 2 +-
sysdeps/unix/sysv/linux/pwritev2.c | 2 +-
sysdeps/unix/sysv/linux/pwritev64v2.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
(limited to 'sysdeps/unix')
diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
index c8bf076..bb08cbc 100644
--- a/sysdeps/unix/sysv/linux/preadv2.c
+++ b/sysdeps/unix/sysv/linux/preadv2.c
@@ -32,7 +32,7 @@ preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
# ifdef __NR_preadv2
ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
LO_HI_LONG (offset), flags);
- if (result >= 0)
+ if (result >= 0 || errno != ENOSYS)
return result;
# endif
/* Trying to emulate the preadv2 syscall flags is troublesome:
diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
index d7400a0..b72a047 100644
--- a/sysdeps/unix/sysv/linux/preadv64v2.c
+++ b/sysdeps/unix/sysv/linux/preadv64v2.c
@@ -30,7 +30,7 @@ preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
#ifdef __NR_preadv64v2
ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
LO_HI_LONG (offset), flags);
- if (result >= 0)
+ if (result >= 0 || errno != ENOSYS)
return result;
#endif
/* Trying to emulate the preadv2 syscall flags is troublesome:
diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
index 29c2264..26333eb 100644
--- a/sysdeps/unix/sysv/linux/pwritev2.c
+++ b/sysdeps/unix/sysv/linux/pwritev2.c
@@ -28,7 +28,7 @@ pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
# ifdef __NR_pwritev2
ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
LO_HI_LONG (offset), flags);
- if (result >= 0)
+ if (result >= 0 || errno != ENOSYS)
return result;
# endif
/* Trying to emulate the pwritev2 syscall flags is troublesome:
diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
index 42da321..17ea905 100644
--- a/sysdeps/unix/sysv/linux/pwritev64v2.c
+++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
@@ -30,7 +30,7 @@ pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
#ifdef __NR_pwritev64v2
ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
LO_HI_LONG (offset), flags);
- if (result >= 0)
+ if (result >= 0 || errno != ENOSYS)
return result;
#endif
/* Trying to emulate the pwritev2 syscall flags is troublesome:
--
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