From 2d226c1e1c194a4737bf17ad8432a479e4e7e4a6 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 16 Jan 2020 18:35:46 +0000 Subject: arm64: entry: mark all entry code as notrace Almost all functions in entry-common.c are marked notrace, with el1_undef and el1_inv being the only exceptions. We appear to have done this on the assumption that there were no exception registers that we needed to snapshot, and thus it was safe to run trace code that might result in further exceptions and clobber those registers. However, until we inherit the DAIF flags, our irq flag tracing is stale, and this discrepancy could set off warnings in some configurations. For example if CONFIG_DEBUG_LOCKDEP is selected and a trace function calls into any flag-checking locking routines. Given we don't expect to trigger el1_undef or el1_inv unless something is already wrong, any irqflag warnigns are liable to mask the information we'd actually care about. Let's keep things simple and mark el1_undef and el1_inv as notrace. Developers can trace do_undefinstr and bad_mode if they really want to monitor these cases. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/kernel/entry-common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 5dce5e56995a..67198142a0fc 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -36,14 +36,14 @@ static void notrace el1_pc(struct pt_regs *regs, unsigned long esr) } NOKPROBE_SYMBOL(el1_pc); -static void el1_undef(struct pt_regs *regs) +static void notrace el1_undef(struct pt_regs *regs) { local_daif_inherit(regs); do_undefinstr(regs); } NOKPROBE_SYMBOL(el1_undef); -static void el1_inv(struct pt_regs *regs, unsigned long esr) +static void notrace el1_inv(struct pt_regs *regs, unsigned long esr) { local_daif_inherit(regs); bad_mode(regs, 0, esr); -- cgit v1.2.3