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| author | Rich Felker <dalias@aerifal.cx> | 2015-11-02 12:39:28 -0500 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2015-11-02 12:41:49 -0500 |
| commit | cb1bf2f321b45a06447133b3db00621b7300c456 (patch) | |
| tree | 50518595b1f221270ec0a209b5252c85d4ba140c /src/thread | |
| parent | fead7e3fc04729b4cc8a5feec4a172b389395212 (diff) | |
| download | musl-cb1bf2f321b45a06447133b3db00621b7300c456.tar.gz musl-cb1bf2f321b45a06447133b3db00621b7300c456.tar.xz musl-cb1bf2f321b45a06447133b3db00621b7300c456.zip | |
properly access mcontext_t program counter in cancellation handler
using the actual mcontext_t definition rather than an overlaid pointer array both improves correctness/readability and eliminates some ugly hacks for archs with 64-bit registers bit 32-bit program counter. also fix UB due to comparison of pointers not in a common array object.
Diffstat (limited to 'src/thread')
| -rw-r--r-- | src/thread/pthread_cancel.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/thread/pthread_cancel.c b/src/thread/pthread_cancel.c index 0151a1ae..6eaf72c4 100644 --- a/src/thread/pthread_cancel.c +++ b/src/thread/pthread_cancel.c @@ -1,3 +1,4 @@ +#define _GNU_SOURCE #include <string.h> #include "pthread_impl.h" #include "syscall.h" @@ -61,15 +62,15 @@ static void cancel_handler(int sig, siginfo_t *si, void *ctx) { pthread_t self = __pthread_self(); ucontext_t *uc = ctx; - const char *ip = ((char **)&uc->uc_mcontext)[CANCEL_REG_IP]; + uintptr_t pc = uc->uc_mcontext.MC_PC; a_barrier(); if (!self->cancel || self->canceldisable == PTHREAD_CANCEL_DISABLE) return; _sigaddset(&uc->uc_sigmask, SIGCANCEL); - if (self->cancelasync || ip >= __cp_begin && ip < __cp_end) { - ((char **)&uc->uc_mcontext)[CANCEL_REG_IP] = (char *)__cp_cancel; + if (self->cancelasync || pc >= (uintptr_t)__cp_begin && pc < (uintptr_t)__cp_end) { + uc->uc_mcontext.MC_PC = (uintptr_t)__cp_cancel; return; } |