[compiler-rt] fd9f7b9 - [lsan][test] Obtaining page size using sysconf(_SC_PAGESIZE)

[via llvm-commits]

Author: zhanglimin
Date: 2023-04-24T14:27:41+08:00
New Revision: fd9f7b90109b3fb9a3ac8df5eb4dd966a359c2f4

URL: https://github.com/llvm/llvm-project/commit/fd9f7b90109b3fb9a3ac8df5eb4dd966a359c2f4
DIFF: https://github.com/llvm/llvm-project/commit/fd9f7b90109b3fb9a3ac8df5eb4dd966a359c2f4.diff

LOG: [lsan][test] Obtaining page size using sysconf(_SC_PAGESIZE)

The effectiveness of the mprotect function depends on whether
the first argument is aligned to a page boundary. If mprotect
doesn't work, the kernel will not generate a SIGSEGV signal for
the process when the calling process tries to access memory in
a manner that violates the protection. If so, this test fails.

The problem for this test is that it uses a fixed 4 kB page size
and is aligned. This fails when the page size is not 4 kB. For
example, this fails on LoongArch which uses a 16 kB pagesize.

Reviewed By: SixWeining, xen0n, MaskRay, vitalybuka

Differential Revision: https://reviews.llvm.org/D148407

Added: 
    

Modified: 
    compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp b/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
index 88fb217883fcd..faa15445658be 100644
--- a/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
+++ b/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
@@ -1,18 +1,22 @@
 // Test that SIGSEGV during leak checking does not crash the process.
 // RUN: %clangxx_lsan -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
 // UNSUPPORTED: ppc
-#include <stdlib.h>
+#include <sanitizer/lsan_interface.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/mman.h>
-#include <sanitizer/lsan_interface.h>
+#include <unistd.h>
 
 char data[10 * 1024 * 1024];
 
 int main() {
+  long pagesize_mask = sysconf(_SC_PAGESIZE) - 1;
   void *p = malloc(10 * 1024 * 1024);
   // surprise-surprise!
-  mprotect((void*)(((unsigned long)p + 4095) & ~4095), 16 * 1024, PROT_NONE);
-  mprotect((void*)(((unsigned long)data + 4095) & ~4095), 16 * 1024, PROT_NONE);
+  mprotect((void *)(((unsigned long)p + pagesize_mask) & ~pagesize_mask),
+           16 * 1024, PROT_NONE);
+  mprotect((void *)(((unsigned long)data + pagesize_mask) & ~pagesize_mask),
+           16 * 1024, PROT_NONE);
   __lsan_do_leak_check();
   fprintf(stderr, "DONE\n");
 }