Messages in this thread | | | From | (Eric W. Biederman) | Date | Thu, 23 May 2019 09:59:20 -0500 | Subject | Re: [REVIEW][PATCH 03/26] signal/arm64: Use force_sig not force_sig_fault for SIGKILL |
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Will Deacon <will.deacon@arm.com> writes:
> On Wed, May 22, 2019 at 07:38:53PM -0500, Eric W. Biederman wrote: >> It really only matters to debuggers but the SIGKILL does not have any >> si_codes that use the fault member of the siginfo union. Correct this >> the simple way and call force_sig instead of force_sig_fault when the >> signal is SIGKILL. >> >> Cc: stable@vger.kernel.org >> Cc: Dave Martin <Dave.Martin@arm.com> >> Cc: James Morse <james.morse@arm.com> >> Cc: Will Deacon <will.deacon@arm.com> >> Fixes: af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals") >> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> >> --- >> arch/arm64/kernel/traps.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c >> index ade32046f3fe..0feb17bdcaa0 100644 >> --- a/arch/arm64/kernel/traps.c >> +++ b/arch/arm64/kernel/traps.c >> @@ -282,6 +282,11 @@ void arm64_notify_die(const char *str, struct pt_regs *regs, >> current->thread.fault_address = 0; >> current->thread.fault_code = err; >> >> + if (signo == SIGKILL) { >> + arm64_show_signal(signo, str); >> + force_sig(signo, current); >> + return; >> + } > > I know it's a bit of a misnomer, but I'd rather do this check inside > arm64_force_sig_fault, since I think we have other callers (e.g. > do_bad_area()) which also blindly pass in SIGKILL here.
Sigh. You are right.
I thought I had checked for that when I made my change there. But do_bad_area will definitely do that, and that was one of the cases that jumped out at me as needing to be fixed, when I skimmed the arm code.
I will respin this patch to move that lower.
> We could rename the thing if necessary.
I would not mind but as long as we aren't misusing the generic bits I won't have alarm bells going of in my head when I look at their users.
Eric
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