[PATCH 2/4] Avoid reading errno in syscall implementations
H.J. Lu
hjl.tools@gmail.com
Thu Sep 10 13:13:00 GMT 2015
OK for master?
H.J.
---
Reading errno is expensive for x86 PIC. With INTERNAL_SYSCALL,
INTERNAL_SYSCALL_ERROR_P, INTERNAL_SYSCALL_ERRNO and
INLINE_SYSCALL_ERROR_RETURN, we can avoid reading errno.
* sysdeps/unix/sysv/linux/eventfd.c (eventfd): Use
INTERNAL_SYSCALL, INTERNAL_SYSCALL_ERROR_P and
INTERNAL_SYSCALL_ERRNO to avoid reading errno.
* sysdeps/unix/sysv/linux/fstatfs64.c (__fstatfs64): Likewise.
* sysdeps/unix/sysv/linux/getrlimit64.c (__getrlimit64):
Likewise.
* sysdeps/unix/sysv/linux/setrlimit64.c (setrlimit64):
Likewise.
* sysdeps/unix/sysv/linux/signalfd.c (signalfd): Likewise.
* sysdeps/unix/sysv/linux/statfs64.c (__statfs64): Likewise.
---
sysdeps/unix/sysv/linux/eventfd.c | 10 +++++++---
sysdeps/unix/sysv/linux/fstatfs64.c | 12 ++++++++----
sysdeps/unix/sysv/linux/getrlimit64.c | 7 +++++--
sysdeps/unix/sysv/linux/lxstat64.c | 6 ++++--
sysdeps/unix/sysv/linux/setrlimit64.c | 7 +++++--
sysdeps/unix/sysv/linux/signalfd.c | 11 ++++++++---
sysdeps/unix/sysv/linux/statfs64.c | 13 +++++++++----
7 files changed, 46 insertions(+), 20 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/eventfd.c b/sysdeps/unix/sysv/linux/eventfd.c
index 55406bb..87d78ca 100644
--- a/sysdeps/unix/sysv/linux/eventfd.c
+++ b/sysdeps/unix/sysv/linux/eventfd.c
@@ -25,11 +25,15 @@ int
eventfd (unsigned int count, int flags)
{
#ifdef __NR_eventfd2
- int res = INLINE_SYSCALL (eventfd2, 2, count, flags);
# ifndef __ASSUME_EVENTFD2
- if (res != -1 || errno != ENOSYS)
-# endif
+ INTERNAL_SYSCALL_DECL (err);
+ int res = INTERNAL_SYSCALL (eventfd2, err, 2, count, flags);
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res, err))
+ || INTERNAL_SYSCALL_ERRNO (res, err) != ENOSYS)
return res;
+# else
+ return INLINE_SYSCALL (eventfd2, 2, count, flags);
+# endif
#endif
#ifndef __ASSUME_EVENTFD2
diff --git a/sysdeps/unix/sysv/linux/fstatfs64.c b/sysdeps/unix/sysv/linux/fstatfs64.c
index af83830..eb21d42 100644
--- a/sysdeps/unix/sysv/linux/fstatfs64.c
+++ b/sysdeps/unix/sysv/linux/fstatfs64.c
@@ -35,12 +35,16 @@ __fstatfs64 (int fd, struct statfs64 *buf)
if (! __no_statfs64)
# endif
{
- int result = INLINE_SYSCALL (fstatfs64, 3, fd, sizeof (*buf), buf);
-
# if __ASSUME_STATFS64 == 0
- if (result == 0 || errno != ENOSYS)
-# endif
+ INTERNAL_SYSCALL_DECL (err);
+ int result = INTERNAL_SYSCALL (fstatfs64, err, 3, fd,
+ sizeof (*buf), buf);
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err))
+ || INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
return result;
+# else
+ return INLINE_SYSCALL (fstatfs64, 3, fd, sizeof (*buf), buf);
+# endif
# if __ASSUME_STATFS64 == 0
__no_statfs64 = 1;
diff --git a/sysdeps/unix/sysv/linux/getrlimit64.c b/sysdeps/unix/sysv/linux/getrlimit64.c
index 100ba62..cca1265 100644
--- a/sysdeps/unix/sysv/linux/getrlimit64.c
+++ b/sysdeps/unix/sysv/linux/getrlimit64.c
@@ -30,8 +30,11 @@ __getrlimit64 (enum __rlimit_resource resource, struct rlimit64 *rlimits)
return INLINE_SYSCALL (prlimit64, 4, 0, resource, NULL, rlimits);
#else
# ifdef __NR_prlimit64
- int res = INLINE_SYSCALL (prlimit64, 4, 0, resource, NULL, rlimits);
- if (res == 0 || errno != ENOSYS)
+ INTERNAL_SYSCALL_DECL (err);
+ int res = INTERNAL_SYSCALL (prlimit64, err, 4, 0, resource, NULL,
+ rlimits);
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res, err))
+ || INTERNAL_SYSCALL_ERRNO (res, err) != ENOSYS)
return res;
# endif
struct rlimit rlimits32;
diff --git a/sysdeps/unix/sysv/linux/lxstat64.c b/sysdeps/unix/sysv/linux/lxstat64.c
index 5d0c051..8afddfd 100644
--- a/sysdeps/unix/sysv/linux/lxstat64.c
+++ b/sysdeps/unix/sysv/linux/lxstat64.c
@@ -30,8 +30,10 @@
int
___lxstat64 (int vers, const char *name, struct stat64 *buf)
{
- int result;
- result = INLINE_SYSCALL (lstat64, 2, name, buf);
+ INTERNAL_SYSCALL_DECL (err);
+ int result = INTERNAL_SYSCALL (lstat64, err, 2, name, buf);
+ if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err)))
+ return INLINE_SYSCALL_ERROR_RETURN (INTERNAL_SYSCALL_ERRNO (result, err));
#if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
if (__builtin_expect (!result, 1) && buf->__st_ino != (__ino_t) buf->st_ino)
buf->st_ino = buf->__st_ino;
diff --git a/sysdeps/unix/sysv/linux/setrlimit64.c b/sysdeps/unix/sysv/linux/setrlimit64.c
index 17f95cb..33e1500 100644
--- a/sysdeps/unix/sysv/linux/setrlimit64.c
+++ b/sysdeps/unix/sysv/linux/setrlimit64.c
@@ -33,8 +33,11 @@ setrlimit64 (resource, rlimits)
return INLINE_SYSCALL (prlimit64, 4, 0, resource, rlimits, NULL);
#else
# ifdef __NR_prlimit64
- int res = INLINE_SYSCALL (prlimit64, 4, 0, resource, rlimits, NULL);
- if (res == 0 || errno != ENOSYS)
+ INTERNAL_SYSCALL_DECL (err);
+ int res = INTERNAL_SYSCALL (prlimit64, err, 4, 0, resource, rlimits,
+ NULL);
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res, err))
+ || INTERNAL_SYSCALL_ERRNO (res, err) != ENOSYS)
return res;
# endif
struct rlimit rlimits32;
diff --git a/sysdeps/unix/sysv/linux/signalfd.c b/sysdeps/unix/sysv/linux/signalfd.c
index 1e242a4..b3c541c 100644
--- a/sysdeps/unix/sysv/linux/signalfd.c
+++ b/sysdeps/unix/sysv/linux/signalfd.c
@@ -26,11 +26,16 @@ int
signalfd (int fd, const sigset_t *mask, int flags)
{
#ifdef __NR_signalfd4
- int res = INLINE_SYSCALL (signalfd4, 4, fd, mask, _NSIG / 8, flags);
# ifndef __ASSUME_SIGNALFD4
- if (res != -1 || errno != ENOSYS)
-# endif
+ INTERNAL_SYSCALL_DECL (err);
+ int res = INTERNAL_SYSCALL (signalfd4, err, 4, fd, mask, _NSIG / 8,
+ flags);
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res, err))
+ || INTERNAL_SYSCALL_ERRNO (res, err) != ENOSYS)
return res;
+# else
+ return INLINE_SYSCALL (signalfd4, 4, fd, mask, _NSIG / 8, flags);
+# endif
#endif
#ifndef __ASSUME_SIGNALFD4
diff --git a/sysdeps/unix/sysv/linux/statfs64.c b/sysdeps/unix/sysv/linux/statfs64.c
index ac5c33f..fdd1667 100644
--- a/sysdeps/unix/sysv/linux/statfs64.c
+++ b/sysdeps/unix/sysv/linux/statfs64.c
@@ -37,12 +37,17 @@ __statfs64 (const char *file, struct statfs64 *buf)
if (! __no_statfs64)
# endif
{
- int result = INLINE_SYSCALL (statfs64, 3, file, sizeof (*buf), buf);
-
# if __ASSUME_STATFS64 == 0
- if (result == 0 || errno != ENOSYS)
-# endif
+ INTERNAL_SYSCALL_DECL (err);
+ int result = INTERNAL_SYSCALL (statfs64, err, 3, file,
+ sizeof (*buf), buf);
+
+ if (!__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err))
+ || INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
return result;
+# else
+ return INLINE_SYSCALL (statfs64, 3, file, sizeof (*buf), buf);
+# endif
# if __ASSUME_STATFS64 == 0
__no_statfs64 = 1;
--
2.4.3
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