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rt: Be more precise with VALGRIND_MAKE_MEM_UNDEFINED

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This commit is contained in:
Brian Anderson 2012-03-03 17:15:51 -08:00
parent c78da1e170
commit cc276fe3c9
3 changed files with 23 additions and 5 deletions
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8
src/rt/rust_stack.cpp
View File

@ -17,13 +17,15 @@ register_valgrind_stack(stk_seg *stk) {
}
void
prepare_valgrind_stack(stk_seg *stk) {
reuse_valgrind_stack(stk_seg *stk, uint8_t *sp) {
#ifndef NVALGRIND
// Establish that the stack is accessible. This must be done when reusing
// old stack segments, since the act of popping the stack previously
// caused valgrind to consider the whole thing inaccessible.
size_t sz = stk->end - (uintptr_t)&stk->data[0];
VALGRIND_MAKE_MEM_UNDEFINED(stk->data, sz);
assert(sp >= stk->data && sp <= (uint8_t*) stk->end
&& "Stack pointer must be inside stack segment");
size_t sz = stk->end - (uintptr_t)sp;
VALGRIND_MAKE_MEM_UNDEFINED(sp, sz);
#endif
}

2
src/rt/rust_stack.h
View File

@ -26,7 +26,7 @@ destroy_stack(memory_region *region, stk_seg *stk);
// Must be called before each time a stack is reused to tell valgrind
// that the stack is accessible.
void
prepare_valgrind_stack(stk_seg *stk);
reuse_valgrind_stack(stk_seg *stk, uint8_t *sp);
// Run a sanity check
void

18
src/rt/rust_task.cpp
View File

@ -571,7 +571,6 @@ rust_task::new_stack(size_t requested_sz) {
LOG(this, mem, "reusing existing stack");
stk = stk->prev;
A(thread, stk->prev == NULL, "Bogus stack ptr");
prepare_valgrind_stack(stk);
return;
} else {
LOG(this, mem, "existing stack is not big enough");
@ -637,12 +636,29 @@ rust_task::del_stack() {
void *
rust_task::next_stack(size_t stk_sz, void *args_addr, size_t args_sz) {
stk_seg *maybe_next_stack = NULL;
if (stk != NULL) {
maybe_next_stack = stk->prev;
}
new_stack(stk_sz + args_sz);
A(thread, stk->end - (uintptr_t)stk->data >= stk_sz + args_sz,
"Did not receive enough stack");
uint8_t *new_sp = (uint8_t*)stk->end;
// Push the function arguments to the new stack
new_sp = align_down(new_sp - args_sz);
// When reusing a stack segment we need to tell valgrind that this area of
// memory is accessible before writing to it, because the act of popping
// the stack previously made all of the stack inaccessible.
if (maybe_next_stack == stk) {
// I don't know exactly where the region ends that valgrind needs us
// to mark accessible. On x86_64 these extra bytes aren't needed, but
// on i386 we get errors without.
int fudge_bytes = 16;
reuse_valgrind_stack(stk, new_sp - fudge_bytes);
}
memcpy(new_sp, args_addr, args_sz);
A(thread, rust_task_thread::get_task() == this,
"Recording the stack limit for the wrong thread");