diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2014-04-16 15:27:52 +0530 |
|---|---|---|
| committer | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2014-04-23 13:21:03 +0200 |
| commit | 8f550715c2b211036fc273add3cb5219397ed312 (patch) | |
| tree | b879f37f1ce879c1785c975b5dbdb38db603e71b /libc | |
| parent | 5799194b75b238491501cbb122f5d7025edd3aa2 (diff) | |
LT.old: Make __errno_location/__h_errno_location thread safe
WHY: errno in uClibc is not thread safe
HOW: __errno_location and it's sibling __h_errno_location need to be called
via PLT - even from within libc. That way when linked with pthread,
intra-uClibc callers will also use the thread safe version.
This is achieved by removing the GI alias for these functions,
ensuring that they get called normally (via PLT)
Verified with ARC LT.old and ARM cubieboard2 buildroot (LT.old)
NPTL is unaffected by this bug.
------------ History behind this patch ---------------------
This is a long standing bug (https://bugs.busybox.net/show_bug.cgi?id=2089)
Others have tried to fix it in past (alteast Peter Korsgaard's patch in 2010),
but somehow failed to be merged (or were backed out afterwards).
http://lists.uclibc.org/pipermail/uclibc/2010-July/044176.html
One of the causes could be side effect of atleast one more bug related to
pthreads and static link which has now been fixed.
http://lists.uclibc.org/pipermail/uclibc/2013-October/047958.html
I have solved this w/o looking at other pacthes but would like to give
credit to Peter and others for confirming that it makes sense.
Cc: Christian Ruppert <christian.ruppert@abilis.com>
CC: Francois Bedard <Francois.Bedard@synopsys.com>
Cc: Joern Rennecke <joern.rennecke@embecosm.com>
Cc: Jeremy Bennett <jeremy.bennett@embecosm.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Khem Raj <raj.khem@gmail.com>
Cc: buildroot@busybox.net
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'libc')
| -rw-r--r-- | libc/misc/internals/__errno_location.c | 1 | ||||
| -rw-r--r-- | libc/misc/internals/__h_errno_location.c | 1 | ||||
| -rw-r--r-- | libc/sysdeps/linux/common/bits/errno.h | 3 |
3 files changed, 0 insertions, 5 deletions
diff --git a/libc/misc/internals/__errno_location.c b/libc/misc/internals/__errno_location.c index be7a9093e..9bbc2d779 100644 --- a/libc/misc/internals/__errno_location.c +++ b/libc/misc/internals/__errno_location.c @@ -16,4 +16,3 @@ int *__errno_location(void) { return &errno; } -libc_hidden_weak(__errno_location) diff --git a/libc/misc/internals/__h_errno_location.c b/libc/misc/internals/__h_errno_location.c index 6653681cb..b30859e81 100644 --- a/libc/misc/internals/__h_errno_location.c +++ b/libc/misc/internals/__h_errno_location.c @@ -16,4 +16,3 @@ int *__h_errno_location(void) { return &h_errno; } -libc_hidden_weak(__h_errno_location) diff --git a/libc/sysdeps/linux/common/bits/errno.h b/libc/sysdeps/linux/common/bits/errno.h index 777338fb1..611b83590 100644 --- a/libc/sysdeps/linux/common/bits/errno.h +++ b/libc/sysdeps/linux/common/bits/errno.h @@ -43,11 +43,8 @@ /* Function to get address of global `errno' variable. */ extern int *__errno_location (void) __THROW __attribute__ ((__const__)); # ifdef _LIBC -# if !defined(__UCLIBC_HAS_TLS__) && !defined(__UCLIBC_HAS_THREADS__) extern int weak_const_function *__errno_location(void); -# endif # endif -libc_hidden_proto(__errno_location) # ifdef __UCLIBC_HAS_THREADS__ /* When using threads, errno is a per-thread value. */ |