[Crash-utility] [PATCH 2/2] arm64: make crash CONFIG_KASAN_HW_TAGS aware
Vinayak Menon
vinayakm.list at gmail.com
Tue Mar 30 13:52:35 UTC 2021
With CONFIG_KASAN_HW_TAGS enabled kvaddr can be tagged
and this results in readmem, vtop etc. fail like below.
"
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 at gmail.com>
---
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)"))) {
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;
};
More information about the Crash-utility
mailing list