[PATCH] stat: Use stat64 syscall if available
Khem Raj
raj.khem at gmail.com
Fri Feb 3 00:12:00 UTC 2012
This is needed for stat'ing loop devices > 255
since otherwise kernel returns EOVERFLOW becasue
it needs st_rdev/st_dev to be larger than 16bits but
in kernel it uses __old_kernel_stat for stat
syscall which has st_rdev/st_dev as unsigned short
Add a testcase
Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
libc/sysdeps/linux/common/stat.c | 12 +++++++++---
test/stat/stat-loop256.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+), 3 deletions(-)
create mode 100644 test/stat/stat-loop256.c
diff --git a/libc/sysdeps/linux/common/stat.c b/libc/sysdeps/linux/common/stat.c
index a6ab291..5850266 100644
--- a/libc/sysdeps/linux/common/stat.c
+++ b/libc/sysdeps/linux/common/stat.c
@@ -14,18 +14,24 @@
#define __NR___syscall_stat __NR_stat
#undef stat
-static __inline__ _syscall2(int, __syscall_stat,
- const char *, file_name, struct kernel_stat *, buf)
int stat(const char *file_name, struct stat *buf)
{
int result;
+#ifdef __NR_stat64
+ struct kernel_stat64 kbuf;
+ result = INLINE_SYSCALL(stat64, 2, file_name, &kbuf);
+ if (result == 0) {
+ __xstat32_conv(&kbuf, buf);
+ }
+#else
struct kernel_stat kbuf;
- result = __syscall_stat(file_name, &kbuf);
+ result = INLINE_SYSCALL(stat, 2, file_name, &kbuf);
if (result == 0) {
__xstat_conv(&kbuf, buf);
}
+#endif
return result;
}
libc_hidden_def(stat)
diff --git a/test/stat/stat-loop256.c b/test/stat/stat-loop256.c
new file mode 100644
index 0000000..fad4962
--- /dev/null
+++ b/test/stat/stat-loop256.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+int main()
+{
+ struct stat statbuf;
+ int ret = 0;
+ char* loop255 = "/dev/loop255";
+ char* loop256 = "/dev/loop256";
+ mode_t mode = 0660;
+ mknod(loop255, mode, 0x7ff);
+ mknod(loop256, mode, 0x100700);
+ ret = stat(loop255, &statbuf);
+ if(ret < 0) {
+ printf("stat: Cant stat %s\n",loop255);
+ unlink(loop255);
+ exit(1);
+ }
+ ret = stat(loop256, &statbuf);
+ if(ret < 0) {
+ printf("stat: Cant stat %s\n",loop256);
+ unlink(loop255);
+ unlink(loop256);
+ exit(1);
+ }
+
+ unlink(loop255);
+ unlink(loop256);
+ exit(0);
+}
+
--
1.7.5.4
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