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charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: otcri6tu5amh8r878hq7f8tuqdy3faw7 X-Rspamd-Queue-Id: CCC9A1C0012 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1722951846-954293 X-HE-Meta: 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 BU1nzRnn l8dDOFJXWpP4mq182iOz93uBdeCBxpzTzE3YQd3IHZQS4HHOIrs23w9D0Z53+KqcQ7bYGryVy3YWT4U41VE9aWeGft0iHFayy5uB8EY9wBMRup2Wug589t2dCijrSX3K0AnanIKQZAiFGi2fhWrn0kO0uAtRDxd5MpQ5nkuieViY5DbTAES4vdMW/d7DyngbgbyjSYqquHccxw4M+aOZMeYWgsHtKuZxh1SrUGSTt4+ODbyV3+fi6ESYidZhf16yJAnhZtFQKmYrNm8Q= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 06, 2024 at 02:33:37PM +0100, Dave Martin wrote: > Hi, > > On Thu, Aug 01, 2024 at 05:01:10PM +0100, Joey Gouly wrote: > > On Thu, Jul 25, 2024 at 04:57:09PM +0100, Dave Martin wrote: > > > On Fri, May 03, 2024 at 02:01:33PM +0100, Joey Gouly wrote: > > > > If a memory fault occurs that is due to an overlay/pkey fault, report that to > > > > userspace with a SEGV_PKUERR. > > > > > > > > Signed-off-by: Joey Gouly > > > > Cc: Catalin Marinas > > > > Cc: Will Deacon > > > > --- > > > > arch/arm64/include/asm/traps.h | 1 + > > > > arch/arm64/kernel/traps.c | 12 ++++++-- > > > > arch/arm64/mm/fault.c | 56 ++++++++++++++++++++++++++++++++-- > > > > 3 files changed, 64 insertions(+), 5 deletions(-) > > > > > > > > diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h > > > > index eefe766d6161..f6f6f2cb7f10 100644 > > > > --- a/arch/arm64/include/asm/traps.h > > > > +++ b/arch/arm64/include/asm/traps.h > > > > @@ -25,6 +25,7 @@ try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn) > > > > void force_signal_inject(int signal, int code, unsigned long address, unsigned long err); > > > > void arm64_notify_segfault(unsigned long addr); > > > > void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str); > > > > +void arm64_force_sig_fault_pkey(int signo, int code, unsigned long far, const char *str, int pkey); > > > > void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str); > > > > void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str); > > > > > > > > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > > > > index 215e6d7f2df8..1bac6c84d3f5 100644 > > > > --- a/arch/arm64/kernel/traps.c > > > > +++ b/arch/arm64/kernel/traps.c > > > > @@ -263,16 +263,24 @@ static void arm64_show_signal(int signo, const char *str) > > > > __show_regs(regs); > > > > } > > > > > > > > -void arm64_force_sig_fault(int signo, int code, unsigned long far, > > > > - const char *str) > > > > +void arm64_force_sig_fault_pkey(int signo, int code, unsigned long far, > > > > + const char *str, int pkey) > > > > { > > > > arm64_show_signal(signo, str); > > > > if (signo == SIGKILL) > > > > force_sig(SIGKILL); > > > > + else if (code == SEGV_PKUERR) > > > > + force_sig_pkuerr((void __user *)far, pkey); > > > > > > Is signo definitely SIGSEGV here? It looks to me like we can get in > > > here for SIGBUS, SIGTRAP etc. > > > > > > si_codes are not unique between different signo here, so I'm wondering > > > whether this should this be: > > > > > > else if (signo == SIGSEGV && code == SEGV_PKUERR) > > > > > > ...? > > > > > > > > > > else > > > > force_sig_fault(signo, code, (void __user *)far); > > > > } > > > > > > > > +void arm64_force_sig_fault(int signo, int code, unsigned long far, > > > > + const char *str) > > > > +{ > > > > + arm64_force_sig_fault_pkey(signo, code, far, str, 0); > > > > > > Is there a reason not to follow the same convention as elsewhere, where > > > -1 is passed for "no pkey"? > > > > > > If we think this should never be called with signo == SIGSEGV && > > > code == SEGV_PKUERR and no valid pkey but if it's messy to prove, then > > > maybe a WARN_ON_ONCE() would be worth it here? > > > > > > > Anshuman suggested to separate them out, which I did like below, I think that > > addresses your comments too? > > > > diff --git arch/arm64/kernel/traps.c arch/arm64/kernel/traps.c > > index 215e6d7f2df8..49bac9ae04c0 100644 > > --- arch/arm64/kernel/traps.c > > +++ arch/arm64/kernel/traps.c > > @@ -273,6 +273,13 @@ void arm64_force_sig_fault(int signo, int code, unsigned long far, > > force_sig_fault(signo, code, (void __user *)far); > > } > > > > +void arm64_force_sig_fault_pkey(int signo, int code, unsigned long far, > > + const char *str, int pkey) > > +{ > > + arm64_show_signal(signo, str); > > + force_sig_pkuerr((void __user *)far, pkey); > > +} > > + > > void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, > > const char *str) > > { > > > > diff --git arch/arm64/mm/fault.c arch/arm64/mm/fault.c > > index 451ba7cbd5ad..1ddd46b97f88 100644 > > --- arch/arm64/mm/fault.c > > +++ arch/arm64/mm/fault.c > > (Guessing where this is means to apply, since there is no hunk header > or context...) Sorry I had some other changes and just mashed the bits into a diff-looking-thing. > > > > > - arm64_force_sig_fault(SIGSEGV, si_code, far, inf->name); > > + if (si_code == SEGV_PKUERR) > > + arm64_force_sig_fault_pkey(SIGSEGV, si_code, far, inf->name, pkey); > > Maybe drop the the signo and si_code argument? This would mean that > arm64_force_sig_fault_pkey() can't be called with a signo/si_code > combination that makes no sense. > > I think pkey faults are always going to be SIGSEGV/SEGV_PKUERR, right? > Or are there other combinations that can apply for these faults? Ah yes, I can simplify it even more, thanks. diff --git arch/arm64/kernel/traps.c arch/arm64/kernel/traps.c index 49bac9ae04c0..d9abb8b390c0 100644 --- arch/arm64/kernel/traps.c +++ arch/arm64/kernel/traps.c @@ -273,10 +273,9 @@ void arm64_force_sig_fault(int signo, int code, unsigned long far, force_sig_fault(signo, code, (void __user *)far); } -void arm64_force_sig_fault_pkey(int signo, int code, unsigned long far, - const char *str, int pkey) +void arm64_force_sig_fault_pkey(unsigned long far, const char *str, int pkey) { - arm64_show_signal(signo, str); + arm64_show_signal(SIGSEGV, str); force_sig_pkuerr((void __user *)far, pkey); } > > > > + else > > + arm64_force_sig_fault(SIGSEGV, si_code, far, inf->name); > > Otherwise yes, I think splitting things this way makes sense. > > Cheers > ---Dave