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| author | Amit Daniel Kachhap <amit.kachhap@arm.com> | 2020-09-14 14:06:56 +0530 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-09-14 12:07:03 +0100 |
| commit | 03c9c8fad6cb5e8fdfb40287fa1cdf8ee2db0b67 (patch) | |
| tree | 28016ad28f6ae4f16e8a63da88513080811f4950 /arch/arm64/kernel/probes/decode-insn.c | |
| parent | 6560edca515e53bb2e7c637ab324313680a133f4 (diff) | |
| download | lwn-03c9c8fad6cb5e8fdfb40287fa1cdf8ee2db0b67.tar.gz lwn-03c9c8fad6cb5e8fdfb40287fa1cdf8ee2db0b67.zip | |
arm64: kprobe: clarify the comment of steppable hint instructions
The existing comment about steppable hint instruction is not complete
and only describes NOP instructions as steppable. As the function
aarch64_insn_is_steppable_hint allows all white-listed instruction
to be probed so the comment is updated to reflect this.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-7-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/probes/decode-insn.c')
| -rw-r--r-- | arch/arm64/kernel/probes/decode-insn.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index c541fb48886e..104101f633b1 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -43,8 +43,10 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) != AARCH64_INSN_SPCLREG_DAIF; /* - * The HINT instruction is is problematic when single-stepping, - * except for the NOP case. + * The HINT instruction is steppable only if it is in whitelist + * and the rest of other such instructions are blocked for + * single stepping as they may cause exception or other + * unintended behaviour. */ if (aarch64_insn_is_hint(insn)) return aarch64_insn_is_steppable_hint(insn); |