Commit 2b79eb73 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 

Pull kprobes updates from Masami Hiramatsu:

 - Skip negative return code check for snprintf in eprobe

 - Add recursive call test cases for kprobe unit test

 - Add 'char' type to probe events to show it as the character instead
   of value

 - Update kselftest kprobe-event testcase to ignore '__pfx_' symbols

 - Fix kselftest to check filter on eprobe event correctly

 - Add filter on eprobe to the README file in tracefs

 - Fix optprobes to check whether there is 'under unoptimizing' optprobe
   when optimizing another kprobe correctly

 - Fix optprobe to check whether there is 'under unoptimizing' optprobe
   when fetching the original instruction correctly

 - Fix optprobe to free 'forcibly unoptimized' optprobe correctly

* tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/eprobe: no need to check for negative ret value for snprintf
  test_kprobes: Add recursed kprobe test case
  tracing/probe: add a char type to show the character value of traced arguments
  selftests/ftrace: Fix probepoint testcase to ignore __pfx_* symbols
  selftests/ftrace: Fix eprobe syntax test case to check filter support
  tracing/eprobe: Fix to add filter on eprobe description in README file
  x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
  x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
  kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
parents 0df82189 c96abaec

Documentation/trace/kprobetrace.rst

+3 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ Synopsis of kprobe_events 
  NAME=FETCHARG : Set NAME as the argument name of FETCHARG.

  FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types

		  (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types

		  (x8/x16/x32/x64), "string", "ustring", "symbol", "symstr"

		  (x8/x16/x32/x64), "char", "string", "ustring", "symbol", "symstr"

                  and bitfield are supported.



  (\*1) only for the probe on function entry (offs == 0).
@@ -82,6 +82,8 @@ Note that the array can be applied to memory type fetchargs, you can not 
apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is

wrong, but '+8($stack):x8[8]' is OK.)



Char type can be used to show the character value of traced arguments.



String type is a special type, which fetches a "null-terminated" string from

kernel space. This means it will fail and store NULL if the string container

has been paged out. "ustring" type is an alternative of string for user-space.

arch/x86/kernel/kprobes/opt.c

+3 −3
Original line number Diff line number Diff line
@@ -46,8 +46,8 @@ unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr) 
		/* This function only handles jump-optimized kprobe */

		if (kp && kprobe_optimized(kp)) {

			op = container_of(kp, struct optimized_kprobe, kp);

			/* If op->list is not empty, op is under optimizing */

			if (list_empty(&op->list))

			/* If op is optimized or under unoptimizing */

			if (list_empty(&op->list) || optprobe_queued_unopt(op))

				goto found;

		}

	}
@@ -353,7 +353,7 @@ int arch_check_optimized_kprobe(struct optimized_kprobe *op) 


	for (i = 1; i < op->optinsn.size; i++) {

		p = get_kprobe(op->kp.addr + i);

		if (p && !kprobe_disabled(p))

		if (p && !kprobe_disarmed(p))

			return -EEXIST;

	}

include/linux/kprobes.h

+2 −0
Original line number Diff line number Diff line
@@ -378,6 +378,8 @@ extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); 
DEFINE_INSN_CACHE_OPS(optinsn);



extern void wait_for_kprobe_optimizer(void);

bool optprobe_queued_unopt(struct optimized_kprobe *op);

bool kprobe_disarmed(struct kprobe *p);

#else /* !CONFIG_OPTPROBES */

static inline void wait_for_kprobe_optimizer(void) { }

#endif /* CONFIG_OPTPROBES */

kernel/kprobes.c

+12 −15
Original line number Diff line number Diff line
@@ -458,7 +458,7 @@ static inline int kprobe_optready(struct kprobe *p) 
}



/* Return true if the kprobe is disarmed. Note: p must be on hash list */

static inline bool kprobe_disarmed(struct kprobe *p)

bool kprobe_disarmed(struct kprobe *p)

{

	struct optimized_kprobe *op;
@@ -555,17 +555,15 @@ static void do_unoptimize_kprobes(void) 
	/* See comment in do_optimize_kprobes() */

	lockdep_assert_cpus_held();



	/* Unoptimization must be done anytime */

	if (list_empty(&unoptimizing_list))

		return;



	if (!list_empty(&unoptimizing_list))

		arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);

	/* Loop on 'freeing_list' for disarming */



	/* Loop on 'freeing_list' for disarming and removing from kprobe hash list */

	list_for_each_entry_safe(op, tmp, &freeing_list, list) {

		/* Switching from detour code to origin */

		op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;

		/* Disarm probes if marked disabled */

		if (kprobe_disabled(&op->kp))

		/* Disarm probes if marked disabled and not gone */

		if (kprobe_disabled(&op->kp) && !kprobe_gone(&op->kp))

			arch_disarm_kprobe(&op->kp);

		if (kprobe_unused(&op->kp)) {

			/*
@@ -662,7 +660,7 @@ void wait_for_kprobe_optimizer(void) 
	mutex_unlock(&kprobe_mutex);

}



static bool optprobe_queued_unopt(struct optimized_kprobe *op)

bool optprobe_queued_unopt(struct optimized_kprobe *op)

{

	struct optimized_kprobe *_op;
@@ -797,14 +795,13 @@ static void kill_optimized_kprobe(struct kprobe *p) 
	op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;



	if (kprobe_unused(p)) {

		/* Enqueue if it is unused */

		list_add(&op->list, &freeing_list);

		/*

		 * Remove unused probes from the hash list. After waiting

		 * for synchronization, this probe is reclaimed.

		 * (reclaiming is done by do_free_cleaned_kprobes().)

		 * Unused kprobe is on unoptimizing or freeing list. We move it

		 * to freeing_list and let the kprobe_optimizer() remove it from

		 * the kprobe hash list and free it.

		 */

		hlist_del_rcu(&op->kp.hlist);

		if (optprobe_queued_unopt(op))

			list_move(&op->list, &freeing_list);

	}



	/* Don't touch the code, because it is already freed. */

kernel/trace/trace.c

+2 −2
Original line number Diff line number Diff line
@@ -5646,7 +5646,7 @@ static const char readme_msg[] = 
#ifdef CONFIG_HIST_TRIGGERS

	"\t           s:[synthetic/]<event> <field> [<field>]\n"

#endif

	"\t           e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>]\n"

	"\t           e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>] [if <filter>]\n"

	"\t           -:[<group>/][<event>]\n"

#ifdef CONFIG_KPROBE_EVENTS

	"\t    place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
@@ -5663,7 +5663,7 @@ static const char readme_msg[] = 
	"\t           $stack<index>, $stack, $retval, $comm,\n"

#endif

	"\t           +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"

	"\t     type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"

	"\t     type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n"

	"\t           b<bit-width>@<bit-offset>/<container-size>, ustring,\n"

	"\t           symstr, <type>\\[<array-size>\\]\n"

#ifdef CONFIG_HIST_TRIGGERS