SafeStack: Use correct unsafe stack sizes
Summary:
When deallocating thread stacks, we use one thread's unsafe stack size
to deallocate another thread's unsafe stack; however, the two sizes may
differ. Record an unsafe stack's size in the thread stack linked list.
Reviewers: pcc, eugenis
Reviewed By: eugenis
Subscribers: delcypher, llvm-commits, #sanitizers, kcc
Differential Revision: https://reviews.llvm.org/D51016
llvm-svn: 340308
diff --git a/compiler-rt/lib/safestack/safestack.cc b/compiler-rt/lib/safestack/safestack.cc
index 920b89b..673f5fd 100644
--- a/compiler-rt/lib/safestack/safestack.cc
+++ b/compiler-rt/lib/safestack/safestack.cc
@@ -152,6 +152,7 @@
struct thread_stack_ll {
struct thread_stack_ll *next;
void *stack_base;
+ size_t size;
pid_t pid;
tid_t tid;
};
@@ -183,7 +184,7 @@
while (*stackp) {
thread_stack_ll *stack = *stackp;
if (stack->pid != pid || TgKill(stack->pid, stack->tid, 0) == -ESRCH) {
- UnmapOrDie(stack->stack_base, unsafe_stack_size + unsafe_stack_guard);
+ UnmapOrDie(stack->stack_base, stack->size);
*stackp = stack->next;
free(stack);
} else
@@ -193,6 +194,7 @@
thread_stack_ll *cur_stack =
(thread_stack_ll *)malloc(sizeof(thread_stack_ll));
cur_stack->stack_base = (char *)unsafe_stack_start - unsafe_stack_guard;
+ cur_stack->size = unsafe_stack_size + unsafe_stack_guard;
cur_stack->pid = pid;
cur_stack->tid = tid;