Misc fixes to kprobes and the faddr2line script, plus a cleanup.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes to kprobes and the faddr2line script, plus a cleanup"

* tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix ';;' typo
  scripts/faddr2line: Add CONFIG_DEBUG_INFO check
  scripts/faddr2line: Fix vmlinux detection on arm64
  x86/kprobes: Update kcb status flag after singlestepping
  kprobes: Forbid probing on trampoline and BPF code areas

arch/x86/kernel/kprobes/core.c

@@ -814,16 +814,20 @@ set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 static void kprobe_post_process(struct kprobe *cur, struct pt_regs *regs,
 			       struct kprobe_ctlblk *kcb)
 {
-	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
-		kcb->kprobe_status = KPROBE_HIT_SSDONE;
-		cur->post_handler(cur, regs, 0);
-	}
-
 	/* Restore back the original saved kprobes variables and continue. */
-	if (kcb->kprobe_status == KPROBE_REENTER)
+	if (kcb->kprobe_status == KPROBE_REENTER) {
+		/* This will restore both kcb and current_kprobe */
 		restore_previous_kprobe(kcb);
-	else
+	} else {
+		/*
+		 * Always update the kcb status because
+		 * reset_curent_kprobe() doesn't update kcb.
+		 */
+		kcb->kprobe_status = KPROBE_HIT_SSDONE;
+		if (cur->post_handler)
+			cur->post_handler(cur, regs, 0);
 		reset_current_kprobe();
+	}
 }
 NOKPROBE_SYMBOL(kprobe_post_process);
 

kernel/events/core.c

@@ -4457,7 +4457,7 @@ int perf_event_read_local(struct perf_event *event, u64 *value,
 
 	*value = local64_read(&event->count);
 	if (enabled || running) {
-		u64 __enabled, __running, __now;;
+		u64 __enabled, __running, __now;
 
 		calc_timer_values(event, &__now, &__enabled, &__running);
 		if (enabled)

kernel/kprobes.c

@@ -1560,7 +1560,8 @@ static int check_kprobe_address_safe(struct kprobe *p,
 	preempt_disable();
 
 	/* Ensure it is not in reserved area nor out of text */
-	if (!kernel_text_address((unsigned long) p->addr) ||
+	if (!(core_kernel_text((unsigned long) p->addr) ||
+	    is_module_text_address((unsigned long) p->addr)) ||
 	    within_kprobe_blacklist((unsigned long) p->addr) ||
 	    jump_label_text_reserved(p->addr, p->addr) ||
 	    static_call_text_reserved(p->addr, p->addr) ||

scripts/faddr2line

@@ -61,6 +61,7 @@ die() {
 READELF="${CROSS_COMPILE:-}readelf"
 ADDR2LINE="${CROSS_COMPILE:-}addr2line"
 AWK="awk"
+GREP="grep"
 
 command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed"
 command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed"
@@ -112,7 +113,9 @@ __faddr2line() {
 	# section offsets.
 	local file_type=$(${READELF} --file-header $objfile |
 		${AWK} '$1 == "Type:" { print $2; exit }')
-	[[ $file_type = "EXEC" ]] && is_vmlinux=1
+	if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
+		is_vmlinux=1
+	fi
 
 	# Go through each of the object's symbols which match the func name.
 	# In rare cases there might be duplicates, in which case we print all
@@ -269,6 +272,8 @@ LIST=0
 [[ ! -f $objfile ]] && die "can't find objfile $objfile"
 shift
 
+${READELF} --section-headers --wide $objfile | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+
 DIR_PREFIX=supercalifragilisticexpialidocious
 find_dir_prefix $objfile