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From b813377f6c746118a9d2625e6b29ffeec4233663 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Fri, 3 Feb 2012 20:06:55 -0800
Subject: [PATCH 3/4] lstat/stat/fstat: Use 64bit version of syscall if
available
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@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
---
libc/sysdeps/linux/common/fstat.c | 18 ++++++++++++++----
libc/sysdeps/linux/common/lstat.c | 19 ++++++++++++++-----
libc/sysdeps/linux/common/stat.c | 18 ++++++++++++++----
test/stat/stat-loop256.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 74 insertions(+), 13 deletions(-)
create mode 100644 test/stat/stat-loop256.c
diff --git a/libc/sysdeps/linux/common/fstat.c b/libc/sysdeps/linux/common/fstat.c
index acc639b..4726a68 100644
--- a/libc/sysdeps/linux/common/fstat.c
+++ b/libc/sysdeps/linux/common/fstat.c
@@ -12,18 +12,28 @@
#include <sys/stat.h>
#include "xstatconv.h"
-#define __NR___syscall_fstat __NR_fstat
-static __inline__ _syscall2(int, __syscall_fstat, int, fd, struct kernel_stat *, buf)
-
int fstat(int fd, struct stat *buf)
{
int result;
+#ifdef __NR_fstat64
+ /* normal stat call has limited values for various stat elements
+ * e.g. uid device major/minor etc.
+ * so we use 64 variant if available
+ * in order to get newer versions of stat elements
+ */
+ struct kernel_stat64 kbuf;
+ result = INLINE_SYSCALL(fstat64, 2, fd, &kbuf);
+ if (result == 0) {
+ __xstat32_conv(&kbuf, buf);
+ }
+#else
struct kernel_stat kbuf;
- result = __syscall_fstat(fd, &kbuf);
+ result = INLINE_SYSCALL(fstat, 2, fd, &kbuf);
if (result == 0) {
__xstat_conv(&kbuf, buf);
}
+#endif
return result;
}
libc_hidden_def(fstat)
diff --git a/libc/sysdeps/linux/common/lstat.c b/libc/sysdeps/linux/common/lstat.c
index aa77447..db72d1f 100644
--- a/libc/sysdeps/linux/common/lstat.c
+++ b/libc/sysdeps/linux/common/lstat.c
@@ -12,19 +12,28 @@
#include <sys/stat.h>
#include "xstatconv.h"
-#define __NR___syscall_lstat __NR_lstat
-static __inline__ _syscall2(int, __syscall_lstat,
- const char *, file_name, struct kernel_stat *, buf)
-
int lstat(const char *file_name, struct stat *buf)
{
int result;
+#ifdef __NR_lstat64
+ /* normal stat call has limited values for various stat elements
+ * e.g. uid device major/minor etc.
+ * so we use 64 variant if available
+ * in order to get newer versions of stat elements
+ */
+ struct kernel_stat64 kbuf;
+ result = INLINE_SYSCALL(lstat64, 2, file_name, &kbuf);
+ if (result == 0) {
+ __xstat32_conv(&kbuf, buf);
+ }
+#else
struct kernel_stat kbuf;
- result = __syscall_lstat(file_name, &kbuf);
+ result = INLINE_SYSCALL(lstat, 2, file_name, &kbuf);
if (result == 0) {
__xstat_conv(&kbuf, buf);
}
+#endif
return result;
}
libc_hidden_def(lstat)
diff --git a/libc/sysdeps/linux/common/stat.c b/libc/sysdeps/linux/common/stat.c
index a6ab291..829f35a 100644
--- a/libc/sysdeps/linux/common/stat.c
+++ b/libc/sysdeps/linux/common/stat.c
@@ -12,20 +12,30 @@
#include <sys/stat.h>
#include "xstatconv.h"
-#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
+ /* normal stat call has limited values for various stat elements
+ * e.g. uid device major/minor etc.
+ * so we use 64 variant if available
+ * in order to get newer versions of stat elements
+ */
+ 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..14284c1
--- /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);
+}
+
--
1.7.8.3
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