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author | Will Deacon <will.deacon@arm.com> | 2016-07-19 16:07:39 +0200 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-19 18:00:29 +0200 |
commit | 44bd887ce10eb8061f6a137f8a73f823957edd82 (patch) | |
tree | 01c45387b5a4e9b7ec7a0328299d569fe8e05da5 /arch/arm64/kernel/probes | |
parent | kprobes: Add arm64 case in kprobe example module (diff) | |
download | linux-44bd887ce10eb8061f6a137f8a73f823957edd82.tar.xz linux-44bd887ce10eb8061f6a137f8a73f823957edd82.zip |
arm64: kprobes: WARN if attempting to step with PSTATE.D=1
Stepping with PSTATE.D=1 is bad news. The step won't generate a debug
exception and we'll likely walk off into random data structures. This
should never happen, but when it does, it's a PITA to debug. Add a
WARN_ON to shout if we realise this is about to take place.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/probes')
-rw-r--r-- | arch/arm64/kernel/probes/kprobes.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 9c70e8812ea9..c89811d1e294 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -254,6 +254,8 @@ static void __kprobes setup_singlestep(struct kprobe *p, if (kcb->kprobe_status == KPROBE_REENTER) spsr_set_debug_flag(regs, 0); + else + WARN_ON(regs->pstate & PSR_D_BIT); /* IRQs and single stepping do not mix well. */ kprobes_save_local_irqflag(kcb, regs); |