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Enhance support for NetBSD in SafeStack 

Summary:
Always try to detect and call internal or real libc symbols instead of
locally installed interceptors.

This covers:
 - GetTid()
 - TgKill()
 - Mmap()
 - Munmap()
 - Mprotect()

This cherry-picks code from sanitizer_common/sanitizer_netbsd.cc.

Reviewers: vitalybuka

Reviewed By: vitalybuka

Subscribers: llvm-commits, mgorny, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D57179

llvm-svn: 352154
This commit is contained in:
Kamil Rytarowski 2019-01-25 02:18:01 +00:00
parent 63bd4e9cd1
commit 63bd043a12
1 changed files with 37 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
compiler-rt/lib/safestack/safestack_platform.h
View File

@ -13,9 +13,13 @@
#ifndef SAFESTACK_PLATFORM_H
#define SAFESTACK_PLATFORM_H
#include "safestack_util.h"
#include "sanitizer_common/sanitizer_platform.h"
#include <dlfcn.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
@ -27,6 +31,8 @@
#if SANITIZER_NETBSD
#include <lwp.h>
extern "C" void *__mmap(void *, size_t, int, int, int, int, off_t);
#endif
#if SANITIZER_FREEBSD
@ -35,11 +41,34 @@
namespace safestack {
#if SANITIZER_NETBSD
static void *GetRealLibcAddress(const char *symbol) {
void *real = dlsym(RTLD_NEXT, symbol);
if (!real)
real = dlsym(RTLD_DEFAULT, symbol);
if (!real) {
fprintf(stderr, "safestack GetRealLibcAddress failed for symbol=%s",
symbol);
abort();
}
return real;
}
#define _REAL(func, ...) real##_##func(__VA_ARGS__)
#define DEFINE__REAL(ret_type, func, ...) \
static ret_type (*real_##func)(__VA_ARGS__) = NULL; \
if (!real_##func) { \
real_##func = (ret_type(*)(__VA_ARGS__))GetRealLibcAddress(#func); \
} \
SFS_CHECK(real_##func);
#endif
using ThreadId = uint64_t;
inline ThreadId GetTid() {
#if SANITIZER_NETBSD
return _lwp_self();
DEFINE__REAL(int, _lwp_self);
return _REAL(_lwp_self);
#elif SANITIZER_FREEBSD
long Tid;
thr_self(&Tid);
@ -51,8 +80,9 @@ inline ThreadId GetTid() {
inline int TgKill(pid_t pid, ThreadId tid, int sig) {
#if SANITIZER_NETBSD
DEFINE__REAL(int, _lwp_kill, int a, int b);
(void)pid;
return _lwp_kill(tid, sig);
return _REAL(_lwp_kill, tid, sig);
#elif SANITIZER_FREEBSD
return syscall(SYS_thr_kill2, pid, tid, sig);
#else
@ -63,7 +93,7 @@ inline int TgKill(pid_t pid, ThreadId tid, int sig) {
inline void *Mmap(void *addr, size_t length, int prot, int flags, int fd,
off_t offset) {
#if SANITIZER_NETBSD
return mmap(addr, length, prot, flags, fd, offset);
return __mmap(addr, length, prot, flags, fd, 0, offset);
#elif defined(__x86_64__) && (SANITIZER_FREEBSD)
return (void *)__syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
#else
@ -73,7 +103,8 @@ inline void *Mmap(void *addr, size_t length, int prot, int flags, int fd,
inline int Munmap(void *addr, size_t length) {
#if SANITIZER_NETBSD
return munmap(addr, length);
DEFINE__REAL(int, munmap, void *a, size_t b);
return _REAL(munmap, addr, length);
#else
return syscall(SYS_munmap, addr, length);
#endif
@ -81,7 +112,8 @@ inline int Munmap(void *addr, size_t length) {
inline int Mprotect(void *addr, size_t length, int prot) {
#if SANITIZER_NETBSD
return mprotect(addr, length, prot);
DEFINE__REAL(int, mprotect, void *a, size_t b, int c);
return _REAL(mprotect, addr, length, prot);
#else
return syscall(SYS_mprotect, addr, length, prot);
#endif