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[PATCH] tile: use better variable naming in INLINE_SYSCALL
- From: Chris Metcalf <cmetcalf at ezchip dot com>
- To: Carlos O'Donell <carlos at redhat dot com>, Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, GNU C Library <libc-alpha at sourceware dot org>
- Cc: Chris Metcalf <cmetcalf at ezchip dot com>
- Date: Tue, 26 May 2015 14:19:15 -0400
- Subject: [PATCH] tile: use better variable naming in INLINE_SYSCALL
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- Authentication-results: spf=fail (sender IP is 12.216.194.146) smtp.mailfrom=ezchip.com; ezchip.com; dkim=none (message not signed) header.d=none;
At issue for INLINE_SYSCALL was that it used "err" and "val"
as variable names in a #define, so that if it was used in a context
where the "caller" was also using "err" or "val", and those
variables were passed in to INLINE_SYSCALL, we would end up
referencing the internal shadowed variables instead.
For example, "char val" in check_may_shrink_heap() in
sysdeps/unix/sysv/linux/malloc-sysdep.h was being shadowed by
the syscall return "val" in INLINE_SYSCALL, causing the "char val"
not to get updated at all, and may_shrink_heap ended up always false.
A similar fix was made to INTERNAL_VSYSCALL_CALL.
---
I will commit this shortly unless someone raises a concern.
ChangeLog | 6 ++++++
sysdeps/unix/sysv/linux/tile/sysdep.h | 29 +++++++++++++++--------------
2 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index f06cb9487d8a..2b11c7fc64e7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-05-26 Chris Metcalf <cmetcalf@ezchip.com>
+
+ * sysdeps/unix/sysv/linux/tile/sysdep.h (INLINE_SYSCALL):
+ Avoid using variables in #defines that might cause shadowing.
+ (INTERNAL_VSYSCALL_CALL): Likewise.
+
2015-05-26 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (HAVE_VSYSCALL):
diff --git a/sysdeps/unix/sysv/linux/tile/sysdep.h b/sysdeps/unix/sysv/linux/tile/sysdep.h
index 30d52e32c9a7..6568dc803485 100644
--- a/sysdeps/unix/sysv/linux/tile/sysdep.h
+++ b/sysdeps/unix/sysv/linux/tile/sysdep.h
@@ -78,16 +78,17 @@
/* Define a macro which expands inline into the wrapper code for a system
call. */
# undef INLINE_SYSCALL
-# define INLINE_SYSCALL(name, nr, args...) \
+# define INLINE_SYSCALL(name, nr, args...) \
({ \
- INTERNAL_SYSCALL_DECL (err); \
- unsigned long val = INTERNAL_SYSCALL (name, err, nr, args); \
- if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (val, err), 0)) \
- { \
- __set_errno (INTERNAL_SYSCALL_ERRNO (val, err)); \
- val = -1; \
- } \
- (long) val; })
+ INTERNAL_SYSCALL_DECL (_sys_err); \
+ unsigned long _sys_val = INTERNAL_SYSCALL (name, _sys_err, nr, args); \
+ if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_val, _sys_err), 0)) \
+ { \
+ __set_errno (INTERNAL_SYSCALL_ERRNO (_sys_val, _sys_err)); \
+ _sys_val = -1; \
+ } \
+ (long) _sys_val; \
+ })
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err, nr, args...) \
@@ -203,11 +204,11 @@
"=R05" (_clobber_r5), "=R10" (_clobber_r10)
-#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
- ({ \
- struct syscall_return_value rv = funcptr (args); \
- err = rv.error; \
- rv.value; \
+#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
+ ({ \
+ struct syscall_return_value _sys_rv = funcptr (args); \
+ err = _sys_rv.error; \
+ _sys_rv.value; \
})
/* List of system calls which are supported as vsyscalls. */
--
2.1.2