mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
synced 2024-12-27 08:29:31 -05:00
80 lines
2.0 KiB
Diff
80 lines
2.0 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Daniel Micay <danielmicay@gmail.com>
|
|
Date: Sat, 7 Feb 2015 20:14:24 -0500
|
|
Subject: [PATCH] add memory protection for at_quick_exit
|
|
|
|
---
|
|
.../lib/libc/stdlib/quick_exit.c | 40 ++++++++++++++++---
|
|
1 file changed, 35 insertions(+), 5 deletions(-)
|
|
|
|
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c b/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
|
|
index ef8cdb1b4..63b54e3fb 100644
|
|
--- a/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
|
|
+++ b/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
|
|
@@ -28,6 +28,9 @@
|
|
|
|
#include <stdlib.h>
|
|
#include <pthread.h>
|
|
+#include <sys/mman.h>
|
|
+#include <sys/prctl.h>
|
|
+#include <unistd.h>
|
|
|
|
/**
|
|
* Linked list of quick exit handlers. This is simpler than the atexit()
|
|
@@ -39,6 +42,10 @@ struct quick_exit_handler {
|
|
void (*cleanup)(void);
|
|
};
|
|
|
|
+static struct quick_exit_handler *pool_page;
|
|
+static struct quick_exit_handler *pool;
|
|
+static size_t pool_size;
|
|
+
|
|
/**
|
|
* Lock protecting the handlers list.
|
|
*/
|
|
@@ -51,16 +58,39 @@ static struct quick_exit_handler *handlers;
|
|
int
|
|
at_quick_exit(void (*func)(void))
|
|
{
|
|
+ size_t page_size = getpagesize();
|
|
struct quick_exit_handler *h;
|
|
-
|
|
- h = malloc(sizeof(*h));
|
|
|
|
- if (NULL == h)
|
|
- return (1);
|
|
- h->cleanup = func;
|
|
pthread_mutex_lock(&atexit_mutex);
|
|
+
|
|
+ if (pool_size < sizeof(*h)) {
|
|
+ void *ptr = mmap(NULL, page_size, PROT_READ|PROT_WRITE,
|
|
+ MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
|
|
+ if (ptr == MAP_FAILED) {
|
|
+ pthread_mutex_unlock(&atexit_mutex);
|
|
+ return (1);
|
|
+ }
|
|
+ prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, page_size,
|
|
+ "at_quick_exit handlers");
|
|
+ pool_page = pool = ptr;
|
|
+ pool_size = page_size;
|
|
+ } else {
|
|
+ if (mprotect(pool_page, page_size, PROT_READ|PROT_WRITE)) {
|
|
+ pthread_mutex_unlock(&atexit_mutex);
|
|
+ return (1);
|
|
+ }
|
|
+ }
|
|
+
|
|
+ h = pool++;
|
|
+ pool_size -= sizeof(*h);
|
|
+
|
|
+ h->cleanup = func;
|
|
+
|
|
h->next = handlers;
|
|
handlers = h;
|
|
+
|
|
+ mprotect(pool_page, page_size, PROT_READ);
|
|
+
|
|
pthread_mutex_unlock(&atexit_mutex);
|
|
return (0);
|
|
}
|