commit 2d005827b874f27535cda72c80b6558d9d4cd30c (tree)
parent 0cdccff51912359b7ec5afa57fbbd5bb69d8f3a2
Author: Andrew Kelley <andrew@ziglang.org>
Date: Mon, 9 Sep 2024 21:16:06 -0700
make lowest stack an internal libfuzzer detail
This value is useful to help determine run uniqueness in the face of
recursion, however it is not valuable to expose to the fuzzing UI.
Diffstat:
6 files changed, 3 insertions(+), 17 deletions(-)
diff --git a/lib/fuzzer.zig b/lib/fuzzer.zig
@@ -28,7 +28,8 @@ fn logOverride(
f.writer().print(prefix1 ++ prefix2 ++ format ++ "\n", args) catch @panic("failed to write to fuzzer log");
}
-export threadlocal var __sancov_lowest_stack: usize = std.math.maxInt(usize);
+/// Helps determine run uniqueness in the face of recursion.
+export threadlocal var __sancov_lowest_stack: usize = 0;
export fn __sanitizer_cov_trace_const_cmp1(arg1: u8, arg2: u8) void {
handleCmp(@returnAddress(), arg1, arg2);
@@ -220,7 +221,6 @@ const Fuzzer = struct {
.n_runs = 0,
.unique_runs = 0,
.pcs_len = pcs.len,
- .lowest_stack = std.math.maxInt(usize),
};
f.seen_pcs.appendSliceAssumeCapacity(std.mem.asBytes(&header));
f.seen_pcs.appendNTimesAssumeCapacity(0, n_bitset_elems * @sizeOf(usize));
@@ -261,8 +261,8 @@ const Fuzzer = struct {
f.input.appendSliceAssumeCapacity(run.input);
try f.mutate();
- _ = @atomicRmw(usize, &header.lowest_stack, .Min, __sancov_lowest_stack, .monotonic);
@memset(f.pc_counters, 0);
+ __sancov_lowest_stack = std.math.maxInt(usize);
f.coverage.reset();
fuzzer_one(f.input.items.ptr, f.input.items.len);
diff --git a/lib/fuzzer/web/index.html b/lib/fuzzer/web/index.html
@@ -147,7 +147,6 @@
<li>Total Runs: <span id="statTotalRuns"></span></li>
<li>Unique Runs: <span id="statUniqueRuns"></span></li>
<li>Coverage: <span id="statCoverage"></span></li>
- <li>Lowest Stack: <span id="statLowestStack"></span></li>
<li>Entry Points: <ul id="entryPointsList"></ul></li>
</ul>
</div>
diff --git a/lib/fuzzer/web/main.js b/lib/fuzzer/web/main.js
@@ -6,7 +6,6 @@
const domStatTotalRuns = document.getElementById("statTotalRuns");
const domStatUniqueRuns = document.getElementById("statUniqueRuns");
const domStatCoverage = document.getElementById("statCoverage");
- const domStatLowestStack = document.getElementById("statLowestStack");
const domEntryPointsList = document.getElementById("entryPointsList");
let wasm_promise = fetch("main.wasm");
@@ -158,7 +157,6 @@
domStatTotalRuns.innerText = totalRuns;
domStatUniqueRuns.innerText = uniqueRuns + " (" + percent(uniqueRuns, totalRuns) + "%)";
domStatCoverage.innerText = coveredSourceLocations + " / " + totalSourceLocations + " (" + percent(coveredSourceLocations, totalSourceLocations) + "%)";
- domStatLowestStack.innerText = unwrapString(wasm_exports.lowestStack());
const entryPoints = unwrapInt32Array(wasm_exports.entryPoints());
resizeDomList(domEntryPointsList, entryPoints.length, "<li></li>");
diff --git a/lib/fuzzer/web/main.zig b/lib/fuzzer/web/main.zig
@@ -106,13 +106,6 @@ export fn decl_source_html(decl_index: Decl.Index) String {
return String.init(string_result.items);
}
-export fn lowestStack() String {
- const header: *abi.CoverageUpdateHeader = @ptrCast(recent_coverage_update.items[0..@sizeOf(abi.CoverageUpdateHeader)]);
- string_result.clearRetainingCapacity();
- string_result.writer(gpa).print("0x{d}", .{header.lowest_stack}) catch @panic("OOM");
- return String.init(string_result.items);
-}
-
export fn totalSourceLocations() usize {
return coverage_source_locations.items.len;
}
diff --git a/lib/std/Build/Fuzz/WebServer.zig b/lib/std/Build/Fuzz/WebServer.zig
@@ -406,7 +406,6 @@ fn sendCoverageContext(
const seen_pcs = cov_header.seenBits();
const n_runs = @atomicLoad(usize, &cov_header.n_runs, .monotonic);
const unique_runs = @atomicLoad(usize, &cov_header.unique_runs, .monotonic);
- const lowest_stack = @atomicLoad(usize, &cov_header.lowest_stack, .monotonic);
if (prev_unique_runs.* != unique_runs) {
// There has been an update.
if (prev_unique_runs.* == 0) {
@@ -431,7 +430,6 @@ fn sendCoverageContext(
const header: abi.CoverageUpdateHeader = .{
.n_runs = n_runs,
.unique_runs = unique_runs,
- .lowest_stack = lowest_stack,
};
const iovecs: [2]std.posix.iovec_const = .{
makeIov(std.mem.asBytes(&header)),
diff --git a/lib/std/Build/Fuzz/abi.zig b/lib/std/Build/Fuzz/abi.zig
@@ -13,7 +13,6 @@ pub const SeenPcsHeader = extern struct {
n_runs: usize,
unique_runs: usize,
pcs_len: usize,
- lowest_stack: usize,
/// Used for comptime assertions. Provides a mechanism for strategically
/// causing compile errors.
@@ -79,7 +78,6 @@ pub const CoverageUpdateHeader = extern struct {
flags: Flags = .{},
n_runs: u64,
unique_runs: u64,
- lowest_stack: u64,
pub const Flags = packed struct(u64) {
tag: ToClientTag = .coverage_update,
