Bug 1957362 - Revert MOZ_CRASH() behavior in ASAN builds to use regular null-pointer accesses r=glandium

ASAN builds should crash the same way as regular builds when encountering a MOZ_CRASH() macro. Changing
this to abort() raised a SIGILL signal instead, which caused the ASAN crash signatures to become
different from regular ones in turn causing confusion in automation.

Differential Revision: https://phabricator.services.mozilla.com/D243658
This commit is contained in:
Gabriele Svelto
2025-04-02 14:24:24 +00:00
parent fdff94954d
commit 8d294334e4

View File

@@ -241,47 +241,41 @@ MOZ_NoReturn(int aLine) {
* MOZ_CrashSequence() executes a sequence that causes the process to crash by
* writing the line number specified in the `aLine` parameter to the address
* provide by `aAddress`. The store is implemented as volatile assembly code to
* ensure it's always included in the output and always executed. This does not
* apply to ASAN builds where we use `__builtin_trap()` instead, as an illegal
* access would trip ASAN's checks.
* ensure it's always included in the output and always executed.
*/
# if !defined(MOZ_ASAN)
static inline void MOZ_CrashSequence(void* aAddress, intptr_t aLine) {
# if defined(__i386__) || defined(__x86_64__)
# if defined(__i386__) || defined(__x86_64__)
asm volatile(
"mov %1, (%0);\n" // Write the line number to the crashing address
: // no output registers
: "r"(aAddress), "r"(aLine));
# elif defined(__arm__) || defined(__aarch64__)
# elif defined(__arm__) || defined(__aarch64__)
asm volatile(
"str %1,[%0];\n" // Write the line number to the crashing address
: // no output registers
: "r"(aAddress), "r"(aLine));
# elif defined(__riscv) && (__riscv_xlen == 64)
# elif defined(__riscv) && (__riscv_xlen == 64)
asm volatile(
"sd %1,0(%0);\n" // Write the line number to the crashing address
: // no output registers
: "r"(aAddress), "r"(aLine));
# elif defined(__sparc__) && defined(__arch64__)
# elif defined(__sparc__) && defined(__arch64__)
asm volatile(
"stx %1,[%0];\n" // Write the line number to the crashing address
: // no output registers
: "r"(aAddress), "r"(aLine));
# elif defined(__loongarch64)
# elif defined(__loongarch64)
asm volatile(
"st.d %1,%0,0;\n" // Write the line number to the crashing address
: // no output registers
: "r"(aAddress), "r"(aLine));
# else
# warning \
"Unsupported architecture, replace the code below with assembly suitable to crash the process"
# else
# warning \
"Unsupported architecture, replace the code below with assembly suitable to crash the process"
asm volatile("" ::: "memory");
*((volatile int*)aAddress) = aLine; /* NOLINT */
# endif
}
# else
# define MOZ_CrashSequence(x, y) __builtin_trap()
# endif
}
/*
* MOZ_CRASH_WRITE_ADDR is the address to be used when performing a forced
@@ -294,7 +288,7 @@ static inline void MOZ_CrashSequence(void* aAddress, intptr_t aLine) {
* SEGV at 0x0.
*/
# ifdef MOZ_UBSAN
# define MOZ_CRASH_WRITE_ADDR 0x1
# define MOZ_CRASH_WRITE_ADDR ((void*)0x1)
# else
# define MOZ_CRASH_WRITE_ADDR NULL
# endif