Skip to content

[dfsan] Fix release_shadow_space.c #94770

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 8, 2024
Merged

[dfsan] Fix release_shadow_space.c #94770

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 10 additions & 4 deletions compiler-rt/test/dfsan/release_shadow_space.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,6 @@
// DFSAN_OPTIONS=no_huge_pages_for_shadow=false RUN: %clang_dfsan %s -DORIGIN_TRACKING -mllvm -dfsan-track-origins=1 -o %t && %run %t
// DFSAN_OPTIONS=no_huge_pages_for_shadow=true RUN: %clang_dfsan %s -DORIGIN_TRACKING -mllvm -dfsan-track-origins=1 -o %t && %run %t

// This test is flaky right now: https://github.com/llvm/llvm-project/issues/91287
// UNSUPPORTED: target={{.*}}

#include <assert.h>
#include <sanitizer/dfsan_interface.h>
#include <stdbool.h>
Expand All @@ -26,7 +23,11 @@ size_t get_rss_kb() {
char buf[256];
while (fgets(buf, sizeof(buf), f) != NULL) {
int64_t rss;
if (sscanf(buf, "Rss: %ld kB", &rss) == 1)
// DFSan's sscanf is broken and doesn't check for ordinary characters in
// the format string, hence we use strstr as a secondary check
// (https://github.com/llvm/llvm-project/issues/94769).
if ((sscanf(buf, "Rss: %ld kB", &rss) == 1) &&
(strstr(buf, "Rss: ") != NULL))
ret += rss;
}
assert(feof(f));
Expand Down Expand Up @@ -73,6 +74,11 @@ int main(int argc, char **argv) {
before, after_mmap, after_mmap_and_set_label, after_fixed_mmap,
after_mmap_and_set_label2, after_munmap);

// This is orders of magnitude larger than we expect (typically < 10,000KB).
// It is a quick check to ensure that the RSS calculation function isn't
// egregriously wrong.
assert(before < 1000000);

const size_t mmap_cost_kb = map_size >> 10;
// Shadow space (1:1 with application memory)
const size_t mmap_shadow_cost_kb = sizeof(dfsan_label) * mmap_cost_kb;
Expand Down