[sanitizer] Add the settings of Read and Write flags in SignalContext for LoongArch
The bit-30 in this `__flags` means the address error is due to memory load, and the
bit-31 means the address error is due to memory store. (see SC_ADDRERR_RD
and SC_ADDRERR_WR in kernel arch/loongarch/include/uapi/asm/sigcontext.h).
`illegal_write_test.cpp` and `illegal_read_test.cpp` have been tested and passed.
Reviewed By: SixWeining, xen0n, XiaodongLoong
Differential Revision: https://reviews.llvm.org/D137231
GitOrigin-RevId: 14cd113e69935e2de9c4d300c3ab01cf83c5d4db
diff --git a/lib/sanitizer_common/sanitizer_linux.cpp b/lib/sanitizer_common/sanitizer_linux.cpp
index 5d1bf95..f23ea9d 100644
--- a/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/lib/sanitizer_common/sanitizer_linux.cpp
@@ -1956,6 +1956,13 @@
u64 esr;
if (!Aarch64GetESR(ucontext, &esr)) return Unknown;
return esr & ESR_ELx_WNR ? Write : Read;
+#elif defined(__loongarch__)
+ u32 flags = ucontext->uc_mcontext.__flags;
+ if (flags & SC_ADDRERR_RD)
+ return SignalContext::Read;
+ if (flags & SC_ADDRERR_WR)
+ return SignalContext::Write;
+ return SignalContext::Unknown;
#elif defined(__sparc__)
// Decode the instruction to determine the access type.
// From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
