[compiler-rt][test] Don't hard-code page size in leak_check_segv.cpp

[tangyouling]

Summary

Don't hard code the page in leak_check_segv.cpp, this breaks on
e.g. LoongArch which defaults to a 16KiB page size.

[xen0n]

This change is actually platform-agnostic. While it looks good to me (minus one nit) I'd like to leave the approval to someone else more familiar with this code.

compiler-rt/test/asan/TestCases/Linux/leak_check_segv.cpp

14

Given you're touching this code and the use sites below all subtract 1 from the page size for use as bitmask, why not kPageBitsMask = GetPageSize() - 1? We're not going to see non-power-of-2 page sizes anytime soon.

[tangyouling]

compiler-rt/test/asan/TestCases/Linux/leak_check_segv.cpp

14

Ok, i will modify it.

[tangyouling]

Address @xen0n's comments.

[XiaodongLoong]

LGTM.

[XiaodongLoong]

compiler-rt/test/asan/TestCases/Linux/leak_check_segv.cpp

14

As @MaskRay said in D140607,

getpagesize is not recommended. Linux can use getauxval(AT_PAGESZ).

Maybe, you also need to change here.

[tangyouling]

compiler-rt/test/asan/TestCases/Linux/leak_check_segv.cpp

14

Yes, will wait for discussion on D140607.

[SixWeining]

This test has been moved from ASAN to LSAN and the issue was fixed in D148407.

compiler-rt/test/asan/TestCases/Linux/leak_check_segv.cpp

 // Test that SIGSEGV during leak checking does not crash the process.
 // RUN: %clangxx_asan -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
 // REQUIRES: leak-detection
-#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() {
   void *p = malloc(10 * 1024 * 1024);
+  const unsigned long kPageBitsMask = getpagesize() - 1;
   // 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 + kPageBitsMask) & ~kPageBitsMask),
+           16 * 1024, PROT_NONE);
+  mprotect((void *)(((unsigned long)data + kPageBitsMask) & ~kPageBitsMask),
+           16 * 1024, PROT_NONE);
   __lsan_do_leak_check();
   fprintf(stderr, "DONE\n");
 }
 
 // CHECK: Tracer caught signal 11
 // CHECK: LeakSanitizer has encountered a fatal error
 // CHECK: HINT: For debugging, try setting {{.*}} LSAN_OPTIONS
 // CHECK-NOT: DONE