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authorLinus Torvalds <torvalds@linux-foundation.org>2021-01-23 00:51:17 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-01-23 00:51:17 +0300
commit1c304c77f7cfc92572cd45cbf045ac2443423ea1 (patch)
treeb70cae1d55f4b2fe56991d2f0ed6d2c781c1a369
parenta9034304ff7b3569af4f159d0c1d4ba33d86cf47 (diff)
parent75bd4bff300b3c5252d4a0e7a959569c62d1dbae (diff)
downloadlinux-1c304c77f7cfc92572cd45cbf045ac2443423ea1.tar.xz
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas: - Correctly mask out bits 63:60 in a kernel tag check fault address (specified as unknown by the architecture). Previously they were just zeroed but for kernel pointers they need to be all ones. - Fix a panic (unexpected kernel BRK exception) caused by kprobes being reentered due to an interrupt. * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kprobes: Fix Uexpected kernel BRK exception at EL1 kasan, arm64: fix pointer tags in KASAN reports
-rw-r--r--arch/arm64/kernel/probes/kprobes.c4
-rw-r--r--arch/arm64/mm/fault.c7
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 89c64ada8732..66aac2881ba8 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -352,8 +352,8 @@ kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned int esr)
unsigned long addr = instruction_pointer(regs);
struct kprobe *cur = kprobe_running();
- if (cur && (kcb->kprobe_status == KPROBE_HIT_SS)
- && ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {
+ if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&
+ ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {
kprobes_restore_local_irqflag(kcb, regs);
post_kprobe_handler(cur, kcb, regs);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 3c40da479899..35d75c60e2b8 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -709,10 +709,11 @@ static int do_tag_check_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
/*
- * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN for tag
- * check faults. Mask them out now so that userspace doesn't see them.
+ * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN
+ * for tag check faults. Set them to corresponding bits in the untagged
+ * address.
*/
- far &= (1UL << 60) - 1;
+ far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK);
do_bad_area(far, esr, regs);
return 0;
}