| author |  Andrew Kelley <andrew@ziglang.org> 2024-08-07 21:05:26-07:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2024-08-08 21:46:36-07:00 |
| log | 4e32edbff5d34dfc779797d73bb61d32ffa02953 |
| tree | 6641a92b99f5488d1891bfb7ef52f3104cc52053 |
| parent | 2cfad202045632945b5007e1d42c2f8a326be44a |
fuzzing: comptime assertions to protect the ABI
compile errors are nice3 files changed, 21 insertions(+), 1 deletions(-)
lib- fuzzer.zig
- std
- Build
lib/fuzzer.zig+7
| ... | ... | @@ -214,6 +214,9 @@ const Fuzzer = struct { |
| 214 | 214 | }); |
| 215 | 215 | defer coverage_file.close(); |
| 216 | 216 | const n_bitset_elems = (flagged_pcs.len + 7) / 8; |
| 217 | comptime assert(SeenPcsHeader.trailing[0] == .pc_addr); | |
| 218 | comptime assert(SeenPcsHeader.trailing[1][0] == .pc_bits); | |
| 219 | comptime assert(SeenPcsHeader.trailing[1][1] == u8); | |
| 217 | 220 | const bytes_len = @sizeOf(SeenPcsHeader) + flagged_pcs.len * @sizeOf(usize) + n_bitset_elems; |
| 218 | 221 | const existing_len = coverage_file.getEndPos() catch |err| { |
| 219 | 222 | fatal("unable to check len of coverage file: {s}", .{@errorName(err)}); |
| ... | ... | @@ -301,6 +304,10 @@ const Fuzzer = struct { |
| 301 | 304 | |
| 302 | 305 | // Track code coverage from all runs. |
| 303 | 306 | { |
| 307 | comptime assert(SeenPcsHeader.trailing[0] == .pc_addr); | |
| 308 | comptime assert(SeenPcsHeader.trailing[1][0] == .pc_bits); | |
| 309 | comptime assert(SeenPcsHeader.trailing[1][1] == u8); | |
| 310 | ||
| 304 | 311 | const seen_pcs = f.seen_pcs.items[@sizeOf(SeenPcsHeader) + f.flagged_pcs.len * @sizeOf(usize) ..]; |
| 305 | 312 | for (seen_pcs, 0..) |*elem, i| { |
| 306 | 313 | const byte_i = i * 8; |
lib/std/Build/Fuzz/WebServer.zig+6
| ... | ... | @@ -7,6 +7,7 @@ const Step = std.Build.Step; |
| 7 | 7 | const Coverage = std.debug.Coverage; |
| 8 | 8 | const abi = std.Build.Fuzz.abi; |
| 9 | 9 | const log = std.log; |
| 10 | const assert = std.debug.assert; | |
| 10 | 11 | |
| 11 | 12 | const WebServer = @This(); |
| 12 | 13 | |
| ... | ... | @@ -383,7 +384,10 @@ fn sendCoverageContext( |
| 383 | 384 | // TODO: make each events URL correspond to one coverage map |
| 384 | 385 | const coverage_map = &coverage_maps[0]; |
| 385 | 386 | const cov_header: *const abi.SeenPcsHeader = @ptrCast(coverage_map.mapped_memory[0..@sizeOf(abi.SeenPcsHeader)]); |
| 387 | comptime assert(abi.SeenPcsHeader.trailing[0] == .pc_addr); | |
| 386 | 388 | const seen_pcs = coverage_map.mapped_memory[@sizeOf(abi.SeenPcsHeader) + coverage_map.source_locations.len * @sizeOf(usize) ..]; |
| 389 | comptime assert(abi.SeenPcsHeader.trailing[1][0] == .pc_bits); | |
| 390 | comptime assert(abi.SeenPcsHeader.trailing[1][1] == u8); | |
| 387 | 391 | const n_runs = @atomicLoad(usize, &cov_header.n_runs, .monotonic); |
| 388 | 392 | const unique_runs = @atomicLoad(usize, &cov_header.unique_runs, .monotonic); |
| 389 | 393 | const lowest_stack = @atomicLoad(usize, &cov_header.lowest_stack, .monotonic); |
| ... | ... | @@ -630,6 +634,7 @@ fn prepareTables( |
| 630 | 634 | gop.value_ptr.mapped_memory = mapped_memory; |
| 631 | 635 | |
| 632 | 636 | const header: *const abi.SeenPcsHeader = @ptrCast(mapped_memory[0..@sizeOf(abi.SeenPcsHeader)]); |
| 637 | comptime assert(abi.SeenPcsHeader.trailing[0] == .pc_addr); | |
| 633 | 638 | const pcs_bytes = mapped_memory[@sizeOf(abi.SeenPcsHeader)..][0 .. header.pcs_len * @sizeOf(usize)]; |
| 634 | 639 | const pcs = std.mem.bytesAsSlice(usize, pcs_bytes); |
| 635 | 640 | const source_locations = try gpa.alloc(Coverage.SourceLocation, pcs.len); |
| ... | ... | @@ -649,6 +654,7 @@ fn addEntryPoint(ws: *WebServer, coverage_id: u64, addr: u64) error{ AlreadyRepo |
| 649 | 654 | |
| 650 | 655 | const coverage_map = ws.coverage_files.getPtr(coverage_id).?; |
| 651 | 656 | const ptr = coverage_map.mapped_memory; |
| 657 | comptime assert(abi.SeenPcsHeader.trailing[0] == .pc_addr); | |
| 652 | 658 | const pcs_bytes = ptr[@sizeOf(abi.SeenPcsHeader)..][0 .. coverage_map.source_locations.len * @sizeOf(usize)]; |
| 653 | 659 | const pcs: []const usize = @alignCast(std.mem.bytesAsSlice(usize, pcs_bytes)); |
| 654 | 660 | const index = std.sort.upperBound(usize, pcs, addr, struct { |
lib/std/Build/Fuzz/abi.zig+8-1
| ... | ... | @@ -8,12 +8,19 @@ |
| 8 | 8 | /// |
| 9 | 9 | /// Trailing: |
| 10 | 10 | /// * pc_addr: usize for each pcs_len |
| 11 | /// * 1 bit per pc_addr, usize elements | |
| 11 | /// * 1 bit per pc_addr, u8 elements | |
| 12 | 12 | pub const SeenPcsHeader = extern struct { |
| 13 | 13 | n_runs: usize, |
| 14 | 14 | unique_runs: usize, |
| 15 | 15 | pcs_len: usize, |
| 16 | 16 | lowest_stack: usize, |
| 17 | ||
| 18 | /// Used for comptime assertions. Provides a mechanism for strategically | |
| 19 | /// causing compile errors. | |
| 20 | pub const trailing = .{ | |
| 21 | .pc_addr, | |
| 22 | .{ .pc_bits, u8 }, | |
| 23 | }; | |
| 17 | 24 | }; |
| 18 | 25 | |
| 19 | 26 | pub const ToClientTag = enum(u8) { |