diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index 0d10307..651f9ab 100644 --- a/Documentation/trace/kprobetrace.rst +++ b/Documentation/trace/kprobetrace.rst @@ -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. diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index e57e07b..57b0037 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -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; } diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index a0b92be..85a64cb 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -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 */ diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1c18ecf..00e177d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -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); - 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. */ diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0fa59ac..45551c7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5646,7 +5646,7 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS "\t s:[synthetic/] []\n" #endif - "\t e[:[/][]] . []\n" + "\t e[:[/][]] . [] [if ]\n" "\t -:[/][]\n" #ifdef CONFIG_KPROBE_EVENTS "\t place: [:][+]|\n" @@ -5663,7 +5663,7 @@ static const char readme_msg[] = "\t $stack, $stack, $retval, $comm,\n" #endif "\t +|-[u](), \\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@/, ustring,\n" "\t symstr, \\[\\]\n" #ifdef CONFIG_HIST_TRIGGERS diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 352b65e..594ac1d 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -923,17 +923,13 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch p = ep->filter_str; for (i = 0; i < argc; i++) { - ret = snprintf(p, len, "%s ", argv[i]); - if (ret < 0) - goto error; - if (ret > len) { - ret = -E2BIG; - goto error; - } + if (i) + ret = snprintf(p, len, " %s", argv[i]); + else + ret = snprintf(p, len, "%s", argv[i]); p += ret; len -= ret; } - p[-1] = '\0'; /* * Ensure the filter string can be parsed correctly. Note, this diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 01ebabb..11008c0 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -50,6 +50,7 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") +DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) { @@ -95,6 +96,7 @@ static const struct fetch_type probe_fetch_types[] = { ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), ASSIGN_FETCH_TYPE_END diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 23acfd1..b4f9955 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -166,6 +166,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x16); DECLARE_BASIC_PRINT_TYPE_FUNC(x32); DECLARE_BASIC_PRINT_TYPE_FUNC(x64); +DECLARE_BASIC_PRINT_TYPE_FUNC(char); DECLARE_BASIC_PRINT_TYPE_FUNC(string); DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c index 1c95e57..0648f71 100644 --- a/lib/test_kprobes.c +++ b/lib/test_kprobes.c @@ -14,6 +14,7 @@ static u32 rand1, preh_val, posth_val; static u32 (*target)(u32 value); +static u32 (*recursed_target)(u32 value); static u32 (*target2)(u32 value); static struct kunit *current_test; @@ -27,18 +28,27 @@ static noinline u32 kprobe_target(u32 value) return (value / div_factor); } +static noinline u32 kprobe_recursed_target(u32 value) +{ + return (value / div_factor); +} + static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs) { KUNIT_EXPECT_FALSE(current_test, preemptible()); - preh_val = (rand1 / div_factor); + + preh_val = recursed_target(rand1); return 0; } static void kp_post_handler(struct kprobe *p, struct pt_regs *regs, unsigned long flags) { + u32 expval = recursed_target(rand1); + KUNIT_EXPECT_FALSE(current_test, preemptible()); - KUNIT_EXPECT_EQ(current_test, preh_val, (rand1 / div_factor)); + KUNIT_EXPECT_EQ(current_test, preh_val, expval); + posth_val = preh_val + div_factor; } @@ -136,6 +146,29 @@ static void test_kprobes(struct kunit *test) unregister_kprobes(kps, 2); } +static struct kprobe kp_missed = { + .symbol_name = "kprobe_recursed_target", + .pre_handler = kp_pre_handler, + .post_handler = kp_post_handler, +}; + +static void test_kprobe_missed(struct kunit *test) +{ + current_test = test; + preh_val = 0; + posth_val = 0; + + KUNIT_EXPECT_EQ(test, 0, register_kprobe(&kp_missed)); + + recursed_target(rand1); + + KUNIT_EXPECT_EQ(test, 2, kp_missed.nmissed); + KUNIT_EXPECT_NE(test, 0, preh_val); + KUNIT_EXPECT_NE(test, 0, posth_val); + + unregister_kprobe(&kp_missed); +} + #ifdef CONFIG_KRETPROBES static u32 krph_val; @@ -336,6 +369,7 @@ static int kprobes_test_init(struct kunit *test) { target = kprobe_target; target2 = kprobe_target2; + recursed_target = kprobe_recursed_target; stacktrace_target = kprobe_stacktrace_target; internal_target = kprobe_stacktrace_internal_target; stacktrace_driver = kprobe_stacktrace_driver; @@ -346,6 +380,7 @@ static int kprobes_test_init(struct kunit *test) static struct kunit_case kprobes_testcases[] = { KUNIT_CASE(test_kprobe), KUNIT_CASE(test_kprobes), + KUNIT_CASE(test_kprobe_missed), #ifdef CONFIG_KRETPROBES KUNIT_CASE(test_kretprobe), KUNIT_CASE(test_kretprobes), diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/eprobes_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/eprobes_syntax_errors.tc index fc1daac..4f5e8c6 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/eprobes_syntax_errors.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/eprobes_syntax_errors.tc @@ -22,6 +22,8 @@ check_error 'e:foo/^bar.1 syscalls/sys_enter_openat' # BAD_EVENT_NAME check_error 'e:foo/bar syscalls/sys_enter_openat arg=^dfd' # BAD_FETCH_ARG check_error 'e:foo/bar syscalls/sys_enter_openat ^arg=$foo' # BAD_ATTACH_ARG -check_error 'e:foo/bar syscalls/sys_enter_openat if ^' # NO_EP_FILTER +if grep -q '\..*\[if \]' README; then + check_error 'e:foo/bar syscalls/sys_enter_openat if ^' # NO_EP_FILTER +fi exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc new file mode 100644 index 0000000..285b477 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc @@ -0,0 +1,47 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event char type argument +# requires: kprobe_events + +case `uname -m` in +x86_64) + ARG1=%di +;; +i[3456]86) + ARG1=%ax +;; +aarch64) + ARG1=%x0 +;; +arm*) + ARG1=%r0 +;; +ppc64*) + ARG1=%r3 +;; +ppc*) + ARG1=%r3 +;; +s390*) + ARG1=%r2 +;; +mips*) + ARG1=%r4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +: "Test get argument (1)" +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +echo "p:test $FUNCTION_FORK" >> kprobe_events +grep -qe "testprobe.* arg1='t'" trace + +echo 0 > events/kprobes/testprobe/enable +: "Test get argument (2)" +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +echo "p:test $FUNCTION_FORK" >> kprobe_events +grep -qe "testprobe.* arg1='t' arg2={'t','e','s','t'}" trace diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/probepoint.tc b/tools/testing/selftests/ftrace/test.d/kprobe/probepoint.tc index 624269c..6842598 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/probepoint.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/probepoint.tc @@ -21,7 +21,7 @@ set_offs() { # prev target next # We have to decode symbol addresses to get correct offsets. # If the offset is not an instruction boundary, it cause -EILSEQ. -set_offs `grep -A1 -B1 ${TARGET_FUNC} /proc/kallsyms | cut -f 1 -d " " | xargs` +set_offs `grep -v __pfx_ /proc/kallsyms | grep -A1 -B1 ${TARGET_FUNC} | cut -f 1 -d " " | xargs` UINT_TEST=no # printf "%x" -1 returns (unsigned long)-1.