Messages in this thread | | | Date | Wed, 13 Apr 2022 22:41:23 +0800 | Subject | Re: [RFC PATCH -next V3 3/6] arm64: add support for machine check error safe | From | Tong Tiangen <> |
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在 2022/4/12 21:08, Kefeng Wang 写道: [...] >> + >> +bool fixup_exception_mc(struct pt_regs *regs) >> +{ >> + const struct exception_table_entry *ex; >> + >> + ex = search_exception_tables(instruction_pointer(regs)); >> + if (!ex) >> + return false; >> + >> + switch (ex->type) { >> + case EX_TYPE_UACCESS_MC: >> + return ex_handler_fixup(ex, regs); >> + } >> + >> + return false; >> +} > > The definition of EX_TYPE_UACCESS_MC is in patch4, please fix it, and if > arm64 exception table
ok, will do next version.
> > is sorted by exception type, we could drop fixup_exception_mc(), right?
In sort_relative_table_with_data(), it seems sorted by insn and data.
> >> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c >> index 77341b160aca..56b13cf8bf1d 100644 >> --- a/arch/arm64/mm/fault.c >> +++ b/arch/arm64/mm/fault.c >> @@ -695,6 +695,30 @@ static int do_bad(unsigned long far, unsigned int >> esr, struct pt_regs *regs) >> return 1; /* "fault" */ >> } >> +static bool arm64_process_kernel_sea(unsigned long addr, unsigned int >> esr, >> + struct pt_regs *regs, int sig, int code) >> +{ >> + if (!IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC)) >> + return false; >> + >> + if (user_mode(regs) || !current->mm) >> + return false; >> + >> + if (apei_claim_sea(regs) < 0) >> + return false; >> + >> + current->thread.fault_address = 0; >> + current->thread.fault_code = esr; >> + > Use set_thread_esr(0, esr) and move it after fixup_exception_mc(); >> + if (!fixup_exception_mc(regs)) >> + return false; >> + >> + arm64_force_sig_fault(sig, code, addr, >> + "Uncorrected hardware memory error in kernel-access\n"); >> + >> + return true; >> +} >> + >> static int do_sea(unsigned long far, unsigned int esr, struct >> pt_regs *regs) >> { >> const struct fault_info *inf; >> @@ -720,6 +744,10 @@ static int do_sea(unsigned long far, unsigned int >> esr, struct pt_regs *regs) >> */ >> siaddr = untagged_addr(far); >> } >> + >> + if (arm64_process_kernel_sea(siaddr, esr, regs, inf->sig, >> inf->code)) >> + return 0; >> + > > Rename arm64_process_kernel_sea() to arm64_do_kernel_sea() > > if (!arm64_do_kernel_sea()) > > arm64_notify_die(); >
Agreed, will do next version.
>> arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, >> esr); >> return 0; >> diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h >> index 546179418ffa..dd952aeecdc1 100644 >> --- a/include/linux/uaccess.h >> +++ b/include/linux/uaccess.h >> @@ -174,6 +174,14 @@ copy_mc_to_kernel(void *dst, const void *src, >> size_t cnt) >> } >> #endif >> +#ifndef copy_mc_to_user >> +static inline unsigned long __must_check >> +copy_mc_to_user(void *dst, const void *src, size_t cnt) >> +{ > Add check_object_size(cnt, src, true); which could make > HARDENED_USERCOPY works.
Agreed, will do next version.
Thanks KeFeng, Tong.
>> + return raw_copy_to_user(dst, src, cnt); >> +} >> +#endif >> + >> static __always_inline void pagefault_disabled_inc(void) >> { >> current->pagefault_disabled++; > .
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