[sanitizer_common] Fix signal_line.cpp on SPARC (llvm#100535)

rorth · web-flow · commit 94394ca980f8 · 2024-07-30T08:59:12.000+02:00
```
  SanitizerCommon-ubsan-sparc-Linux :: Linux/signal_line.cpp
```
currently `FAIL`s on Linux/sparc64 (32 and 64-bit) for `n == 2`. Instead
of the expected `SIGSEGV`, the test dies with `SIGBUS`. `strace` reveals
that this is due to a unaligned access:
```
--- SIGBUS {si_signo=SIGBUS, si_code=BUS_ADRALN, si_addr=0x1} ---
```
which is to be expected on a strict-alignment target like SPARC. Fixed
by changing the invalid pointer to be better aligned.

Tested on `sparc64-unknown-linux-gnu` and `x86_64-pc-linux-gnu`.
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/signal_line.cpp b/compiler-rt/test/sanitizer_common/TestCases/Linux/signal_line.cpp
@@ -20,7 +20,8 @@ int main(int argc, char **argv) {
   // CHECK1: SUMMARY: [[SAN]]: SEGV {{.*}}signal_line.cpp:[[@LINE-2]]:[[TAB]] in main
 
   if (n == 2)
-    *((volatile int *)0x1) = __LINE__;
+    // Allow for strict-alignment targets that require natural alignment.
+    *((volatile int *)0x8) = __LINE__;
   // CHECK2: #{{[0-9]+ .*}}main {{.*}}signal_line.cpp:[[@LINE-1]]:[[TAB:[0-9]+]]
   // CHECK2: SUMMARY: [[SAN]]: SEGV {{.*}}signal_line.cpp:[[@LINE-2]]:[[TAB]] in main
 }

Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,8 @@ int main(int argc, char **argv) {`
`20`	`20`	`// CHECK1: SUMMARY: [[SAN]]: SEGV {{.*}}signal_line.cpp:[[@LINE-2]]:[[TAB]] in main`
`21`	`21`
`22`	`22`	`if (n == 2)`
`23`		`- ((volatile int )0x1) = __LINE__;`
	`23`	`+ // Allow for strict-alignment targets that require natural alignment.`
	`24`	`+ ((volatile int )0x8) = __LINE__;`
`24`	`25`	`// CHECK2: #{{[0-9]+ .}}main {{.}}signal_line.cpp:[[@LINE-1]]:[[TAB:[0-9]+]]`
`25`	`26`	`// CHECK2: SUMMARY: [[SAN]]: SEGV {{.*}}signal_line.cpp:[[@LINE-2]]:[[TAB]] in main`
`26`	`27`	`}`