From 4ec98e6db9f24a9f4716685c62c9f6c348fec45b Mon Sep 17 00:00:00 2001 From: Asahi Lina Date: Sat, 11 Feb 2023 18:13:02 +0900 Subject: [PATCH] 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: 22991d8d5725 ("soc: apple: rtkit: Add register dump decoding to crashlog") Signed-off-by: Asahi Lina Reviewed-by: Eric Curtin Signed-off-by: Arnd Bergmann --- drivers/soc/apple/rtkit-crashlog.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/soc/apple/rtkit-crashlog.c b/drivers/soc/apple/rtkit-crashlog.c index dfa74b3..8319e36 100644 --- a/drivers/soc/apple/rtkit-crashlog.c +++ b/drivers/soc/apple/rtkit-crashlog.c @@ -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(®s, 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"); -- 2.7.4