Unverified Commit 4ec98e6d authored by Asahi Lina's avatar Asahi Lina Committed by Arnd Bergmann
Browse files

soc: apple: rtkit: Do not copy the reg state structure to the stack 



The register state struct is 848 bytes, which ends up bloating the
apple_rtkit_crashlog_dump_regs stack frame beyond 1024 on some
32-bit platforms, triggering compile warnings.

This doesn't matter for 64BIT/ARM64, but there's also no good reason to
copy the structure to the stack in this case. We can use __packed to
avoid alignment issues, there are no double-read hazards, and this is a
fatal error path so performance does not matter.

Fixes: 22991d8d ("soc: apple: rtkit: Add register dump decoding to crashlog")
Signed-off-by: default avatarAsahi Lina <lina@asahilina.net>
Reviewed-by: default avatarEric Curtin <ecurtin@redhat.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 68907175

drivers/soc/apple/rtkit-crashlog.c

+13 −13
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ struct apple_rtkit_crashlog_regs { 
	u64 unk_X;

	u64 esr;

	u64 unk_Z;

};

} __packed;

static_assert(sizeof(struct apple_rtkit_crashlog_regs) == 0x350);



static void apple_rtkit_crashlog_dump_str(struct apple_rtkit *rtk, u8 *bfr,
@@ -126,18 +126,18 @@ static void apple_rtkit_crashlog_dump_mailbox(struct apple_rtkit *rtk, u8 *bfr, 
static void apple_rtkit_crashlog_dump_regs(struct apple_rtkit *rtk, u8 *bfr,

					   size_t size)

{

	struct apple_rtkit_crashlog_regs regs;

	struct apple_rtkit_crashlog_regs *regs;

	const char *el;

	int i;



	if (size < sizeof(regs)) {

	if (size < sizeof(*regs)) {

		dev_warn(rtk->dev, "RTKit: Regs section too small: 0x%zx", size);

		return;

	}



	memcpy(&regs, bfr, sizeof(regs));

	regs = (struct apple_rtkit_crashlog_regs *)bfr;



	switch (regs.psr & PSR_MODE_MASK) {

	switch (regs->psr & PSR_MODE_MASK) {

	case PSR_MODE_EL0t:

		el = "EL0t";

		break;
@@ -160,11 +160,11 @@ static void apple_rtkit_crashlog_dump_regs(struct apple_rtkit *rtk, u8 *bfr, 


	dev_warn(rtk->dev, "RTKit: Exception dump:");

	dev_warn(rtk->dev, "  == Exception taken from %s ==", el);

	dev_warn(rtk->dev, "  PSR    = 0x%llx", regs.psr);

	dev_warn(rtk->dev, "  PC     = 0x%llx\n", regs.pc);

	dev_warn(rtk->dev, "  ESR    = 0x%llx\n", regs.esr);

	dev_warn(rtk->dev, "  FAR    = 0x%llx\n", regs.far);

	dev_warn(rtk->dev, "  SP     = 0x%llx\n", regs.sp);

	dev_warn(rtk->dev, "  PSR    = 0x%llx", regs->psr);

	dev_warn(rtk->dev, "  PC     = 0x%llx\n", regs->pc);

	dev_warn(rtk->dev, "  ESR    = 0x%llx\n", regs->esr);

	dev_warn(rtk->dev, "  FAR    = 0x%llx\n", regs->far);

	dev_warn(rtk->dev, "  SP     = 0x%llx\n", regs->sp);

	dev_warn(rtk->dev, "\n");



	for (i = 0; i < 31; i += 4) {
@@ -172,12 +172,12 @@ static void apple_rtkit_crashlog_dump_regs(struct apple_rtkit *rtk, u8 *bfr, 
			dev_warn(rtk->dev,

					 "  x%02d-x%02d = %016llx %016llx %016llx %016llx\n",

					 i, i + 3,

					 regs.regs[i], regs.regs[i + 1],

					 regs.regs[i + 2], regs.regs[i + 3]);

					 regs->regs[i], regs->regs[i + 1],

					 regs->regs[i + 2], regs->regs[i + 3]);

		else

			dev_warn(rtk->dev,

					 "  x%02d-x%02d = %016llx %016llx %016llx\n", i, i + 3,

					 regs.regs[i], regs.regs[i + 1], regs.regs[i + 2]);

					 regs->regs[i], regs->regs[i + 1], regs->regs[i + 2]);

	}



	dev_warn(rtk->dev, "\n");