all: prevent fakePC overflow on 386 in libfuzzer mode

fakePC uses hash.Sum32, which returns an uint32. However, libfuzzer
trace/hook functions declare fakePC argument as int, causing overflow on
386 archs.

Fixing this by changing fakePC argument to uint to prevent the overflow.

Fixes #56141

Change-Id: I3994c461319983ab70065f90bf61539a363e0a2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/441996
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/src/runtime/libfuzzer.go b/src/runtime/libfuzzer.go
index 6bfaef823b..013e7165b2 100644
--- a/src/runtime/libfuzzer.go
+++ b/src/runtime/libfuzzer.go
@@ -20,49 +20,49 @@ const retSledSize = 512
 // This may result in these functions having callers that are nosplit. That is why they must be nosplit.
 //
 //go:nosplit
-func libfuzzerTraceCmp1(arg0, arg1 uint8, fakePC int) {
+func libfuzzerTraceCmp1(arg0, arg1 uint8, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_cmp1, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceCmp2(arg0, arg1 uint16, fakePC int) {
+func libfuzzerTraceCmp2(arg0, arg1 uint16, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_cmp2, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceCmp4(arg0, arg1 uint32, fakePC int) {
+func libfuzzerTraceCmp4(arg0, arg1 uint32, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_cmp4, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceCmp8(arg0, arg1 uint64, fakePC int) {
+func libfuzzerTraceCmp8(arg0, arg1 uint64, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_cmp8, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceConstCmp1(arg0, arg1 uint8, fakePC int) {
+func libfuzzerTraceConstCmp1(arg0, arg1 uint8, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_const_cmp1, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceConstCmp2(arg0, arg1 uint16, fakePC int) {
+func libfuzzerTraceConstCmp2(arg0, arg1 uint16, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_const_cmp2, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceConstCmp4(arg0, arg1 uint32, fakePC int) {
+func libfuzzerTraceConstCmp4(arg0, arg1 uint32, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_const_cmp4, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }
 
 //go:nosplit
-func libfuzzerTraceConstCmp8(arg0, arg1 uint64, fakePC int) {
+func libfuzzerTraceConstCmp8(arg0, arg1 uint64, fakePC uint) {
 	fakePC = fakePC % retSledSize
 	libfuzzerCallTraceIntCmp(&__sanitizer_cov_trace_const_cmp8, uintptr(arg0), uintptr(arg1), uintptr(fakePC))
 }