generic-library/bionic
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Merge "Revert "Improve stack overflow diagnostics.""

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This commit is contained in:
Guang Zhu
2013-07-17 03:17:19 +00:00
committed by Gerrit Code Review
parent 8c1b96681a d14dc3b87f
commit 2cf5a6f662
3 changed files with 33 additions and 57 deletions
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8
libc/bionic/pthread_attr.cpp
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@@ -30,16 +30,12 @@
#include "pthread_internal.h"
// Traditionally we give threads a 1MiB stack. When we started allocating per-thread
// alternate signal stacks to ease debugging of stack overflows, we subtracted the
// same amount we were using there from the default thread stack size. This should
// keep memory usage roughly constant.
#define DEFAULT_THREAD_STACK_SIZE ((1 * 1024 * 1024) - SIGSTKSZ)
#define DEFAULT_STACK_SIZE (1024 * 1024)
int pthread_attr_init(pthread_attr_t* attr) {
attr->flags = 0;
attr->stack_base = NULL;
attr->stack_size = DEFAULT_THREAD_STACK_SIZE;
attr->stack_size = DEFAULT_STACK_SIZE;
attr->guard_size = PAGE_SIZE;
attr->sched_policy = SCHED_NORMAL;
attr->sched_priority = 0;

21
libc/bionic/pthread_create.cpp
View File

@@ -62,15 +62,6 @@ void __init_tls(pthread_internal_t* thread) {
thread->tls[i] = NULL;
}
// Create and set an alternate signal stack.
stack_t ss;
ss.ss_sp = mmap(NULL, SIGSTKSZ, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
if (ss.ss_sp != MAP_FAILED) {
ss.ss_size = SIGSTKSZ;
ss.ss_flags = 0;
sigaltstack(&ss, NULL);
}
// Slot 0 must point to itself. The x86 Linux kernel reads the TLS from %fs:0.
thread->tls[TLS_SLOT_SELF] = thread->tls;
thread->tls[TLS_SLOT_THREAD_ID] = thread;
@@ -80,9 +71,7 @@ void __init_tls(pthread_internal_t* thread) {
__set_tls(thread->tls);
}
// This trampoline is called from the assembly _pthread_clone function.
// Our 'tls' and __pthread_clone's 'child_stack' are one and the same, just growing in
// opposite directions.
// This trampoline is called from the assembly _pthread_clone() function.
extern "C" void __thread_entry(void* (*func)(void*), void* arg, void** tls) {
// Wait for our creating thread to release us. This lets it have time to
// notify gdb about this thread before we start doing anything.
@@ -198,12 +187,8 @@ int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
thread->attr.flags |= PTHREAD_ATTR_FLAG_USER_STACK;
}
// Make room for the TLS area.
// The child stack is the same address, just growing in the opposite direction.
// At offsets >= 0, we have the TLS slots.
// At offsets < 0, we have the child stack.
// Make room for TLS.
void** tls = (void**)((uint8_t*)(thread->attr.stack_base) + thread->attr.stack_size - BIONIC_TLS_SLOTS * sizeof(void*));
void* child_stack = tls;
// Create a mutex for the thread in TLS_SLOT_SELF to wait on once it starts so we can keep
// it from doing anything until after we notify the debugger about it
@@ -219,7 +204,7 @@ int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
int flags = CLONE_FILES | CLONE_FS | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM;
int tid = __pthread_clone(start_routine, child_stack, flags, arg);
int tid = __pthread_clone(start_routine, tls, flags, arg);
if (tid < 0) {
int clone_errno = errno;
if ((thread->attr.flags & PTHREAD_ATTR_FLAG_USER_STACK) == 0) {