Fix pthread_attr_getstack under valgrind.
valgrind seems to mess with the stack enough that the kernel will
report "[stack:pid]" rather than "[stack]" in /proc/self/maps, so
switch to the task-specific file instead to force "[stack]". (There
are two conditions in the kernel code that decides which form to
output.)
Bug: 17897476
Change-Id: Iff85ceb6d52e8716251fab4e45d95a27184c5529
diff --git a/libc/bionic/pthread_attr.cpp b/libc/bionic/pthread_attr.cpp
index c93970a..c65ccc1 100644
--- a/libc/bionic/pthread_attr.cpp
+++ b/libc/bionic/pthread_attr.cpp
@@ -31,6 +31,7 @@
#include <inttypes.h>
#include <stdio.h>
#include <sys/resource.h>
+#include <unistd.h>
#include "private/bionic_string_utils.h"
#include "private/ErrnoRestorer.h"
@@ -126,8 +127,12 @@
stack_limit.rlim_cur = 8 * 1024 * 1024;
}
- // It doesn't matter which thread we are; we're just looking for "[stack]".
- FILE* fp = fopen("/proc/self/maps", "re");
+ // It shouldn't matter which thread we are because we're just looking for "[stack]", but
+ // valgrind seems to mess with the stack enough that the kernel will report "[stack:pid]"
+ // instead if you look in /proc/self/maps, so we need to look in /proc/pid/task/pid/maps.
+ char path[64];
+ snprintf(path, sizeof(path), "/proc/self/task/%d/maps", getpid());
+ FILE* fp = fopen(path, "re");
if (fp == NULL) {
return errno;
}
@@ -143,7 +148,7 @@
}
}
}
- __libc_fatal("No [stack] line found in /proc/self/maps!");
+ __libc_fatal("No [stack] line found in \"%s\"!", path);
}
int pthread_attr_getstack(const pthread_attr_t* attr, void** stack_base, size_t* stack_size) {