musl/arch/x32/pthread_arch.h

static inline struct pthread *__pthread_self()
{
	struct pthread *self;
	__asm__ __volatile__ ("mov %%fs:0,%0" : "=r" (self) );
	return self;
}

#define TP_ADJ(p) (p)

#define MC_PC gregs[REG_RIP]

#define CANARY canary2
import vanilla x86_64 code as x32 2014-01-07 21:43:34 +00:00			`static inline struct pthread *__pthread_self()`
			`{`
			`struct pthread *self;`
			`__asm__ __volatile__ ("mov %%fs:0,%0" : "=r" (self) );`
			`return self;`
			`}`

			`#define TP_ADJ(p) (p)`

properly access mcontext_t program counter in cancellation handler using the actual mcontext_t definition rather than an overlaid pointer array both improves correctness/readability and eliminates some ugly hacks for archs with 64-bit registers bit 32-bit program counter. also fix UB due to comparison of pointers not in a common array object. 2015-11-02 17:39:28 +00:00			`#define MC_PC gregs[REG_RIP]`
fix stack protector crashes on x32 & powerpc due to misplaced TLS canary i386, x86_64, x32, and powerpc all use TLS for stack protector canary values in the default stack protector ABI, but the location only matched the ABI on i386 and x86_64. on x32, the expected location for the canary contained the tid, thus producing spurious mismatches (resulting in process termination) upon fork. on powerpc, the expected location contained the stdio_locks list head, so returning from a function after calling flockfile produced spurious mismatches. in both cases, the random canary was not present, and a predictable value was used instead, making the stack protector hardening much less effective than it should be. in the current fix, the thread structure has been expanded to have canary fields at all three possible locations, and archs that use a non-default location must define a macro in pthread_arch.h to choose which location is used. for most archs (which lack TLS canary ABI) the choice does not matter. 2015-05-06 22:37:19 +00:00
			`#define CANARY canary2`