diff options
Diffstat (limited to 'src/runtime/libfuzzer.go')
| -rw-r--r-- | src/runtime/libfuzzer.go | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/runtime/libfuzzer.go b/src/runtime/libfuzzer.go index 920ac575f5..c136eaf5fe 100644 --- a/src/runtime/libfuzzer.go +++ b/src/runtime/libfuzzer.go @@ -9,6 +9,7 @@ package runtime import "unsafe" func libfuzzerCallWithTwoByteBuffers(fn, start, end *byte) +func libfuzzerCall4(fn *byte, fakePC uintptr, s1, s2 unsafe.Pointer, result uintptr) func libfuzzerCall(fn *byte, arg0, arg1 uintptr) func libfuzzerTraceCmp1(arg0, arg1 uint8) { @@ -59,6 +60,31 @@ func init() { libfuzzerCallWithTwoByteBuffers(&__sanitizer_cov_pcs_init, &pcTables[0], &pcTables[size-1]) } +// We call libFuzzer's __sanitizer_weak_hook_strcmp function +// which takes the following four arguments: +// 1- caller_pc: location of string comparison call site +// 2- s1: first string used in the comparison +// 3- s2: second string used in the comparison +// 4- result: an integer representing the comparison result. Libfuzzer only distinguishes between two cases: +// - 0 means that the strings are equal and the comparison will be ignored by libfuzzer. +// - Any other value means that strings are not equal and libfuzzer takes the comparison into consideration. +// Here, we pass 1 when the strings are not equal. +func libfuzzerHookStrCmp(s1, s2 string, fakePC int) { + if s1 != s2 { + libfuzzerCall4(&__sanitizer_weak_hook_strcmp, uintptr(fakePC), cstring(s1), cstring(s2), uintptr(1)) + } + // if s1 == s2 we could call the hook with a last argument of 0 but this is unnecessary since this case will be then + // ignored by libfuzzer +} + +// This function has now the same implementation as libfuzzerHookStrCmp because we lack better checks +// for case-insensitive string equality in the runtime package. +func libfuzzerHookEqualFold(s1, s2 string, fakePC int) { + if s1 != s2 { + libfuzzerCall4(&__sanitizer_weak_hook_strcmp, uintptr(fakePC), cstring(s1), cstring(s2), uintptr(1)) + } +} + //go:linkname __sanitizer_cov_trace_cmp1 __sanitizer_cov_trace_cmp1 //go:cgo_import_static __sanitizer_cov_trace_cmp1 var __sanitizer_cov_trace_cmp1 byte @@ -106,3 +132,7 @@ var __stop___sancov_cntrs byte //go:linkname __sanitizer_cov_pcs_init __sanitizer_cov_pcs_init //go:cgo_import_static __sanitizer_cov_pcs_init var __sanitizer_cov_pcs_init byte + +//go:linkname __sanitizer_weak_hook_strcmp __sanitizer_weak_hook_strcmp +//go:cgo_import_static __sanitizer_weak_hook_strcmp +var __sanitizer_weak_hook_strcmp byte |