From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-stable@sourceware.org
Subject: [2.26 COMMITTED 2/2] Fix misreported errno on preadv2/pwritev2 (BZ#23579)
Date: Mon, 01 Jan 2018 00:00:00 -0000 [thread overview]
Message-ID: <20180928192152.15005-2-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20180928192152.15005-1-adhemerval.zanella@linaro.org>
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.
(cherry picked from commit 7a16bdbb9ff4122af0a28dc20996c95352011fdd)
---
ChangeLog | 14 +++++
NEWS | 1 +
misc/tst-preadvwritev2-common.c | 77 ++++++++++++++++++++++++++-
misc/tst-preadvwritev2.c | 2 +
misc/tst-preadvwritev64v2.c | 2 +
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 +-
9 files changed, 99 insertions(+), 5 deletions(-)
diff --git a/NEWS b/NEWS
index d5e3403e8b..299fba24b1 100644
--- a/NEWS
+++ b/NEWS
@@ -151,6 +151,7 @@ The following bugs are resolved with this release:
[23363] stdio-common/tst-printf.c has non-free license
[23456] Wrong index_cpu_LZCNT
[23459] COMMON_CPUID_INDEX_80000001 isn't populated for Intel processors
+ [23579] libc: Errors misreported in preadv2
\f
Version 2.26
diff --git a/misc/tst-preadvwritev2-common.c b/misc/tst-preadvwritev2-common.c
index 8abedc14d0..9570882fa6 100644
--- a/misc/tst-preadvwritev2-common.c
+++ b/misc/tst-preadvwritev2-common.c
@@ -19,10 +19,85 @@
#include <limits.h>
#include <support/check.h>
+#ifndef RWF_HIPRI
+# define RWF_HIPRI 0
+#endif
+#ifndef RWF_DSYNC
+# define RWF_DSYNC 0
+#endif
+#ifndef RWF_SYNC
+# define RWF_SYNC 0
+#endif
+#ifndef RWF_NOWAIT
+# define RWF_NOWAIT 0
+#endif
+#ifndef RWF_APPEND
+# define RWF_APPEND 0
+#endif
+#define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT \
+ | RWF_APPEND)
+
+static void
+do_test_with_invalid_fd (void)
+{
+ char buf[256];
+ struct iovec iov = { buf, sizeof buf };
+
+ /* Check with flag being 0 to use the fallback code which calls pwritev
+ or writev. */
+ TEST_VERIFY (preadv2 (-1, &iov, 1, -1, 0) == -1);
+ TEST_COMPARE (errno, EBADF);
+ TEST_VERIFY (pwritev2 (-1, &iov, 1, -1, 0) == -1);
+ TEST_COMPARE (errno, EBADF);
+
+ /* Same tests as before but with flags being different than 0. Since
+ there is no emulation for any flag value, fallback code returns
+ ENOTSUP. This is different running on a kernel with preadv2/pwritev2
+ support, where EBADF is returned). */
+ TEST_VERIFY (preadv2 (-1, &iov, 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EBADF || errno == ENOTSUP);
+ TEST_VERIFY (pwritev2 (-1, &iov, 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EBADF || errno == ENOTSUP);
+}
+
+static void
+do_test_with_invalid_iov (void)
+{
+ {
+ char buf[256];
+ struct iovec iov;
+
+ iov.iov_base = buf;
+ iov.iov_len = (size_t)SSIZE_MAX + 1;
+
+ TEST_VERIFY (preadv2 (temp_fd, &iov, 1, 0, 0) == -1);
+ TEST_COMPARE (errno, EINVAL);
+ TEST_VERIFY (pwritev2 (temp_fd, &iov, 1, 0, 0) == -1);
+ TEST_COMPARE (errno, EINVAL);
+
+ /* Same as for invalid file descriptor tests, emulation fallback
+ first checks for flag value and return ENOTSUP. */
+ TEST_VERIFY (preadv2 (temp_fd, &iov, 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EINVAL || errno == ENOTSUP);
+ TEST_VERIFY (pwritev2 (temp_fd, &iov, 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EINVAL || errno == ENOTSUP);
+ }
+
+ {
+ /* An invalid iovec buffer should trigger an invalid memory access
+ or an error (Linux for instance returns EFAULT). */
+ struct iovec iov[IOV_MAX+1] = { 0 };
+
+ TEST_VERIFY (preadv2 (temp_fd, iov, IOV_MAX + 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EINVAL || errno == ENOTSUP);
+ TEST_VERIFY (pwritev2 (temp_fd, iov, IOV_MAX + 1, 0, RWF_HIPRI) == -1);
+ TEST_VERIFY (errno == EINVAL || errno == ENOTSUP);
+ }
+}
+
static void
do_test_with_invalid_flags (void)
{
-#define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT)
/* Set the next bit from the mask of all supported flags. */
int invalid_flag = __builtin_clz (RWF_SUPPORTED);
invalid_flag = 0x1 << ((sizeof (int) * CHAR_BIT) - invalid_flag);
diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
index 225f5e59c1..bebd2e56d6 100644
--- a/misc/tst-preadvwritev2.c
+++ b/misc/tst-preadvwritev2.c
@@ -30,6 +30,8 @@ do_test (void)
{
do_test_with_invalid_flags ();
do_test_without_offset ();
+ do_test_with_invalid_fd ();
+ do_test_with_invalid_iov ();
return do_test_with_offset (0);
}
diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
index facdbdca61..3d03e32484 100644
--- a/misc/tst-preadvwritev64v2.c
+++ b/misc/tst-preadvwritev64v2.c
@@ -32,6 +32,8 @@ do_test (void)
{
do_test_with_invalid_flags ();
do_test_without_offset ();
+ do_test_with_invalid_fd ();
+ do_test_with_invalid_iov ();
return do_test_with_offset (0);
}
diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
index a7a3aeeee6..c7f91025f2 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 53c946861c..4dbea0a8d4 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 17677df98d..a33ed56c55 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 f5753eede5..f0ffd2f1f6 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:
--
2.17.1
prev parent reply other threads:[~2018-09-28 19:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-01 0:00 [2.26 COMMITTED 1/2] preadv2/pwritev2: Handle offset == -1 [BZ #22753] Adhemerval Zanella
2018-01-01 0:00 ` Adhemerval Zanella [this message]
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