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charset=us-ascii Content-Disposition: inline In-Reply-To: <20240801160110.GC841837@e124191.cambridge.arm.com> X-Rspamd-Queue-Id: 1B76214000D X-Stat-Signature: 3xu5883mdt9azq1fuf81rmomfuumfefc X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1722951233-658816 X-HE-Meta: U2FsdGVkX18gNMxNzpntNxJVSP55SG7JCRanSEl9dl0WDKHUdm2Ud1+tMQ/q3c5ghn+6bDed3StsNr7g3Ltsjp4RYTI0U4P0cybD9BR0FqBhw1kbElZDmiAT37mQG2WMNWdiwD2n/Ui+J2BbyfJE1XD2NjyNdnnXuoasWaTPr2370m+Y5LTmjMhW27fQss4WXI3dyycSuphvzQnp3UeS+YcDvqBBfrb5FZVQ7M/wcvNxCQr2wgKGXonjftUZHJqUJ/bgME8sRrKR0lb/8zmWvRLBZ4RpEIDVPAvONSoESxiv8n+jV6Jo0t6D0Sp6xhjjOUuIv9csocJklb74SM4YRuEcYyYPgahKoYoMU8EahxcNFGtwBIWL0ORpxhqreYVrrzEnuT2kvI/aIs3rWGxWT8P/+kCrNO0FYCGh3laHkeOQIJuhA/fXpTcFTwrKxxE1znSXLaydUtGIzP+LYqhxlybCFv2F7LjEa+SXmdD8YK/o2h490DmGzQOnfKgBnhY9DY3k0iCx9TL8yxFhxpSusDZfzqri4VaIFDl9GhXvy53Q7vVK1ICizE2WhOwIXwwleYIP1U2EmxCMUvW3KI45a5/sQbk61FJBM7qsVqJyIKGwjoKwN8Li0k8EB1igSFfhsTysp1SIzq4hmCW5FNTOQt6hyVVF4HVhwT2dhU3ihVNHsGcPy0imMAK6qMI4/6xoIjSw/OqNsRZ8wS95B/C+TVmKc5Cnb2Ka+STVTdxHjnt9/N9o+IUSK494AyrzsxVJBoke7C+KDynvR3/8q0QAA8SUdeG1nx7/Dk/4x1zYBO5AgNUOlHLCY73oRsSUsjwdWKL+qiLMZFNRBkCr9T8GGj5O/8X5AVOEEFbfcMUdQaNQjGbr/CoANnfT3zdmHhBZBNZLysSWZpNj+MIYWOYEqokzVGro557tHKnwncybtUvfiMDutuU5P7XzhKisg3cL+0Nk3LZnEj4HT80Dbay Vj/Qu6yb kLDIgG7DC1/dtJJktnBizcL5U5AYPlDh+ctM+j+8ZfsPeU/xly15TXkEB8fbJ61z0rMS+23R1CqH+HO2ndUlxskNnv5zqK5LFxX7Gz6r0jPn5eT12G+ZJC0+sKYRWTYzekPDBXy/zjuhFlZdkVGDEPVX2ENPR92Z4ezunPkTZxPFO585GvlRy5tpV7tY9770v+e8+m6pBoK6BrHb+7IdlI5O6xQkWZUVFHG8JjjdQx/9No3ZM+QBq9KXey82JRPQJnY+M4jCXAh+5omg= 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: 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...) > > - 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? > + else > + arm64_force_sig_fault(SIGSEGV, si_code, far, inf->name); Otherwise yes, I think splitting things this way makes sense. Cheers ---Dave