[PATCH v3 1/3] libc: fix setting return value and errno in fallocate()

Yuriy Kolerov yuriy.kolerov at synopsys.com
Wed Sep 23 12:43:37 UTC 2015


fallocate system call must return 0 on success. On error, -1 is returned
and errno is set to indicate the error.

However there is an error in fallocate which is fixed by this patch - it
does not set errno and returns invalid value on error (it returns error
code instead of -1).

This error is detected in LTP's test kernel/syscalls/fallocate02:

    ----------->8----------
    fallocate(..., 1, 0, 1024) failed, expected errno:9: TEST_ERRNO=0
    fallocate(..., 1, -1024, 1024) failed, expected errno:22: TEST_ERRNO=0
    fallocate(..., 1, 1024, -1024) failed, expected errno:22: TEST_ERRNO=0
    fallocate(..., 1, 12288, 0) failed, expected errno:22: TEST_ERRNO=0
    fallocate(..., 1, 12288, -1024) failed, expected errno:22: TEST_ERRNO=0
    fallocate(..., 1, -24576, 1024) failed, expected errno:22: TEST_ERRNO=0
    ----------->8----------

Signed-off-by: Yuriy Kolerov <yuriy.kolerov at synopsys.com>
---
 libc/sysdeps/linux/common/fallocate.c   | 9 ++++++---
 libc/sysdeps/linux/common/fallocate64.c | 9 ++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/libc/sysdeps/linux/common/fallocate.c b/libc/sysdeps/linux/common/fallocate.c
index b231226..b2309e9 100644
--- a/libc/sysdeps/linux/common/fallocate.c
+++ b/libc/sysdeps/linux/common/fallocate.c
@@ -12,6 +12,7 @@
 #include <fcntl.h>
 #include <bits/kernel-features.h>
 #include <stdint.h>
+#include <errno.h>
 
 #if defined __NR_fallocate
 extern __typeof(fallocate) __libc_fallocate attribute_hidden;
@@ -34,9 +35,11 @@ int attribute_hidden __libc_fallocate(int fd, int mode, __off_t offset, __off_t
 # else
 # error your machine is neither 32 bit or 64 bit ... it must be magical
 # endif
-	if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err)))
-		return INTERNAL_SYSCALL_ERRNO (ret, err);
-	return 0;
+	if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err))) {
+		__set_errno(INTERNAL_SYSCALL_ERRNO (ret, err));
+		ret = -1;
+	}
+	return ret;
 }
 
 # if defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU
diff --git a/libc/sysdeps/linux/common/fallocate64.c b/libc/sysdeps/linux/common/fallocate64.c
index cf75693..1aa351e 100644
--- a/libc/sysdeps/linux/common/fallocate64.c
+++ b/libc/sysdeps/linux/common/fallocate64.c
@@ -13,6 +13,7 @@
 #include <fcntl.h>
 #include <bits/kernel-features.h>
 #include <stdint.h>
+#include <errno.h>
 
 #if defined __NR_fallocate
 
@@ -27,9 +28,11 @@ int attribute_hidden __libc_fallocate64(int fd, int mode, __off64_t offset,
 	INTERNAL_SYSCALL_DECL(err);
 	ret = (int) (INTERNAL_SYSCALL(fallocate, err, 6, fd, mode,
 		OFF64_HI_LO (offset), OFF64_HI_LO (len)));
-	if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err)))
-		return INTERNAL_SYSCALL_ERRNO (ret, err);
-	return 0;
+	if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err))) {
+		__set_errno(INTERNAL_SYSCALL_ERRNO (ret, err));
+		ret = -1;
+	}
+	return ret;
 }
 
 #  if defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU
-- 
2.2.0



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