Hi Pingfan, On Mon, Apr 26, 2021 at 8:06 PM piliu <piliu@xxxxxxxxxx> wrote: > > > > On 4/26/21 7:17 PM, piliu wrote: > > > > Hi Vinayak, > > > > On 3/30/21 9:52 PM, Vinayak Menon wrote: > >> With CONFIG_KASAN_HW_TAGS enabled kvaddr can be tagged > >> and this results in readmem, vtop etc. fail like below. > Sorry for the limited knowledge of this field. I have more question > during the reviewing. > > -1.is this reproducible with SW TAGS? > -2. HW TAGS aims for malloc, while here I see the handling LR, PC. > It seems that they are more related to "Pointer Authentication" I have not tried with SW tags. CONFIG_KASAN_HW_TAGS can be found here in kernel https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/Kconfig.kasan?h=v5.12#n102 The MTE based kasan is used for tagging malloc too. With CONFIG_KASAN_HW_TAGS it is used to tag kernel memory, replacing the regular kasan. > > Thanks, > Pingfan > >> > >> " > >> please wait... (gathering kmem slab cache data) > >> crash: invalid kernel virtual address: f0ffff878000201c type: > >> "kmem_cache objsize/object_size" > >> crash: get_active_set: no tasks found? > >> please wait... (gathering task table data) > >> crash: invalid kernel virtual address: f1ffff87f51e3530 type: > >> "xa_node shift" > >> " > >> > >> Make the mask introduced for pointer authentication generic > >> and use it in vtop and kvaddr validation. > >> > >> Signed-off-by: Vinayak Menon <vinayakm.list@xxxxxxxxx> > >> --- > >> arm64.c | 50 +++++++++++++++++++++++++++++++------------------- > >> defs.h | 2 +- > >> 2 files changed, 32 insertions(+), 20 deletions(-) > >> > >> diff --git a/arm64.c b/arm64.c > >> index 5b59972..bb41cbb 100644 > >> --- a/arm64.c > >> +++ b/arm64.c > >> @@ -85,7 +85,8 @@ static int arm64_get_kvaddr_ranges(struct > >> vaddr_range *); > >> static void arm64_get_crash_notes(void); > >> static void arm64_calc_VA_BITS(void); > >> static int arm64_is_uvaddr(ulong, struct task_context *); > >> -static void arm64_calc_KERNELPACMASK(void); > >> +static int arm64_is_kvaddr(ulong); > >> +static void arm64_calc_KERNELTAGMASK(void); > >> /* > >> @@ -215,7 +216,7 @@ arm64_init(int when) > >> machdep->pagemask = ~((ulonglong)machdep->pageoffset); > >> arm64_calc_VA_BITS(); > >> - arm64_calc_KERNELPACMASK(); > >> + arm64_calc_KERNELTAGMASK(); > >> ms = machdep->machspec; > >> if (ms->VA_BITS_ACTUAL) { > >> ms->page_offset = ARM64_PAGE_OFFSET_ACTUAL; > >> @@ -228,7 +229,7 @@ arm64_init(int when) > >> machdep->kvbase = ARM64_VA_START; > >> ms->userspace_top = ARM64_USERSPACE_TOP; > >> } > >> - machdep->is_kvaddr = generic_is_kvaddr; > >> + machdep->is_kvaddr = arm64_is_kvaddr; > >> machdep->kvtop = arm64_kvtop; > >> if (machdep->flags & NEW_VMEMMAP) { > >> struct syment *sp; > >> @@ -477,7 +478,7 @@ arm64_init(int when) > >> case LOG_ONLY: > >> machdep->machspec = &arm64_machine_specific; > >> arm64_calc_VA_BITS(); > >> - arm64_calc_KERNELPACMASK(); > >> + arm64_calc_KERNELTAGMASK(); > >> arm64_calc_phys_offset(); > >> machdep->machspec->page_offset = ARM64_PAGE_OFFSET; > >> arm64_calc_physvirt_offset(); > >> @@ -608,7 +609,7 @@ arm64_dump_machdep_table(ulong arg) > >> fprintf(fp, " dis_filter: arm64_dis_filter()\n"); > >> fprintf(fp, " cmd_mach: arm64_cmd_mach()\n"); > >> fprintf(fp, " get_smp_cpus: arm64_get_smp_cpus()\n"); > >> - fprintf(fp, " is_kvaddr: generic_is_kvaddr()\n"); > >> + fprintf(fp, " is_kvaddr: arm64_is_kvaddr()\n"); > >> fprintf(fp, " is_uvaddr: arm64_is_uvaddr()\n"); > >> fprintf(fp, " value_to_symbol: > >> generic_machdep_value_to_symbol()\n"); > >> fprintf(fp, " init_kernel_pgd: arm64_init_kernel_pgd\n"); > >> @@ -668,9 +669,9 @@ arm64_dump_machdep_table(ulong arg) > >> fprintf(fp, "%ld\n", ms->VA_BITS_ACTUAL); > >> else > >> fprintf(fp, "(unused)\n"); > >> - fprintf(fp, "CONFIG_ARM64_KERNELPACMASK: "); > >> - if (ms->CONFIG_ARM64_KERNELPACMASK) > >> - fprintf(fp, "%lx\n", ms->CONFIG_ARM64_KERNELPACMASK); > >> + fprintf(fp, "CONFIG_ARM64_KERNELTAGMASK: "); > >> + if (ms->CONFIG_ARM64_KERNELTAGMASK) > >> + fprintf(fp, "%lx\n", ms->CONFIG_ARM64_KERNELTAGMASK); > >> else > >> fprintf(fp, "(unused)\n"); > >> fprintf(fp, " userspace_top: %016lx\n", ms->userspace_top); > >> @@ -1208,6 +1209,9 @@ arm64_kvtop(struct task_context *tc, ulong > >> kvaddr, physaddr_t *paddr, int verbos > >> if (!IS_KVADDR(kvaddr)) > >> return FALSE; > >> + if (kvaddr & (1UL << 63)) > >> + kvaddr |= machdep->machspec->CONFIG_ARM64_KERNELTAGMASK; > >> + > >> if (!vt->vmalloc_start) { > >> *paddr = VTOP(kvaddr); > >> return TRUE; > >> @@ -1828,7 +1832,7 @@ arm64_is_kernel_exception_frame(struct bt_info > >> *bt, ulong stkptr) > >> if (INSTACK(regs->sp, bt) && INSTACK(regs->regs[29], bt) && > >> !(regs->pstate & (0xffffffff00000000ULL | PSR_MODE32_BIT)) && > >> is_kernel_text(regs->pc) && > >> - is_kernel_text(regs->regs[30] | > >> ms->CONFIG_ARM64_KERNELPACMASK)) { > >> + is_kernel_text(regs->regs[30] | > >> ms->CONFIG_ARM64_KERNELTAGMASK)) { > >> switch (regs->pstate & PSR_MODE_MASK) > >> { > >> case PSR_MODE_EL1t: > >> @@ -2198,8 +2202,8 @@ arm64_unwind_frame(struct bt_info *bt, struct > >> arm64_stackframe *frame) > >> frame->sp = fp + 0x10; > >> frame->fp = GET_STACK_ULONG(fp); > >> frame->pc = GET_STACK_ULONG(fp + 8); > >> - if (is_kernel_text(frame->pc | ms->CONFIG_ARM64_KERNELPACMASK)) > >> - frame->pc |= ms->CONFIG_ARM64_KERNELPACMASK; > >> + if (is_kernel_text(frame->pc | ms->CONFIG_ARM64_KERNELTAGMASK)) > >> + frame->pc |= ms->CONFIG_ARM64_KERNELTAGMASK; > >> if ((frame->fp == 0) && (frame->pc == 0)) > >> return FALSE; > >> @@ -2869,8 +2873,8 @@ arm64_print_text_symbols(struct bt_info *bt, > >> struct arm64_stackframe *frame, FIL > >> for (i = (start - bt->stackbase)/sizeof(ulong); i < > >> LONGS_PER_STACK; i++) { > >> up = (ulong *)(&bt->stackbuf[i*sizeof(ulong)]); > >> val = *up; > >> - if (is_kernel_text(val | ms->CONFIG_ARM64_KERNELPACMASK)) { > >> - val |= ms->CONFIG_ARM64_KERNELPACMASK; > >> + if (is_kernel_text(val | ms->CONFIG_ARM64_KERNELTAGMASK)) { > >> + val |= ms->CONFIG_ARM64_KERNELTAGMASK; > >> name = closest_symbol(val); > >> fprintf(ofp, " %s[%s] %s at %lx", > >> bt->flags & BT_ERROR_MASK ? > >> @@ -3205,8 +3209,8 @@ arm64_print_exception_frame(struct bt_info *bt, > >> ulong pt_regs, int mode, FILE *o > >> rows = 4; > >> } else { > >> LR = regs->regs[30]; > >> - if (is_kernel_text (LR | ms->CONFIG_ARM64_KERNELPACMASK)) > >> - LR |= ms->CONFIG_ARM64_KERNELPACMASK; > >> + if (is_kernel_text (LR | ms->CONFIG_ARM64_KERNELTAGMASK)) > >> + LR |= ms->CONFIG_ARM64_KERNELTAGMASK; > >> SP = regs->sp; > >> top_reg = 29; > >> is_64_bit = TRUE; > >> @@ -4102,6 +4106,14 @@ arm64_calc_virtual_memory_ranges(void) > >> } > >> static int > >> +arm64_is_kvaddr(ulong addr) > >> +{ > >> + if (addr & (1UL << 63)) > >> + addr |= machdep->machspec->CONFIG_ARM64_KERNELTAGMASK; > >> + return generic_is_kvaddr(addr); > >> +} > >> + > >> +static int > >> arm64_is_uvaddr(ulong addr, struct task_context *tc) > >> { > >> return (addr < machdep->machspec->userspace_top); > >> @@ -4129,21 +4141,21 @@ arm64_swp_offset(ulong pte) > >> return pte; > >> } > >> -static void arm64_calc_KERNELPACMASK(void) > >> +static void arm64_calc_KERNELTAGMASK(void) > >> { > >> ulong value = 0; > >> char *string; > >> - if ((string = pc->read_vmcoreinfo("NUMBER(KERNELPACMASK)"))) { > >> + if ((string = pc->read_vmcoreinfo("NUMBER(KERNELTAGMASK)"))) { > > > > I git grep 5.12 kernel, but did not find this. Do you plan to do it in > > kernel firstly? > > > > Thanks, > > Pingfan > >> value = htol(string, QUIET, NULL); > >> free(string); > >> } else if (machdep->machspec->tag_mask) { > >> value = machdep->machspec->tag_mask; > >> } > >> - machdep->machspec->CONFIG_ARM64_KERNELPACMASK = value; > >> + machdep->machspec->CONFIG_ARM64_KERNELTAGMASK = value; > >> if (CRASHDEBUG(1)) > >> - fprintf(fp, "CONFIG_ARM64_KERNELPACMASK: %lx\n", value); > >> + fprintf(fp, "CONFIG_ARM64_KERNELTAGMASK: %lx\n", value); > >> } > >> #endif /* ARM64 */ > >> diff --git a/defs.h b/defs.h > >> index d406f5f..770c335 100644 > >> --- a/defs.h > >> +++ b/defs.h > >> @@ -3329,7 +3329,7 @@ struct machine_specific { > >> ulong VA_BITS_ACTUAL; > >> ulong CONFIG_ARM64_VA_BITS; > >> ulong VA_START; > >> - ulong CONFIG_ARM64_KERNELPACMASK; > >> + ulong CONFIG_ARM64_KERNELTAGMASK; > >> ulong physvirt_offset; > >> ulong tag_mask; > >> }; > >> > >> -- > >> Crash-utility mailing list > >> Crash-utility@xxxxxxxxxx > >> https://listman.redhat.com/mailman/listinfo/crash-utility > >> > > > > -- > > Crash-utility mailing list > > Crash-utility@xxxxxxxxxx > > https://listman.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/crash-utility
