diff mbox

[3/6] Avoid reading errno in syscall implementations

Message ID 20150914141910.GC26042@gmail.com
State New, archived
Headers show

Commit Message

H.J. Lu Sept. 14, 2015, 2:19 p.m. UTC
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 mbox

Patch

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;