From 196b6389a363e0d7e6b6f2654b9889f9c821b9d3 Mon Sep 17 00:00:00 2001 From: Song Chen Date: Fri, 30 Dec 2022 14:33:19 +0800 Subject: [PATCH 1/3] kernel/trace: Introduce trace_probe_print_args and use it in *probes print_probe_args is currently inplemented in trace_probe_tmpl.h and included by *probes, as a result, each probe has an identical copy. This patch will move it to trace_probe.c as an new API, each probe calls it to print their args in trace file. Link: https://lore.kernel.org/all/1672382000-18304-1-git-send-email-chensong_2000@189.cn/ Signed-off-by: Song Chen Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_eprobe.c | 2 +- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 27 +++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 2 ++ kernel/trace/trace_probe_tmpl.h | 28 ---------------------------- kernel/trace/trace_uprobe.c | 2 +- 6 files changed, 33 insertions(+), 32 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 594ac1d086aa..9d0ebcffb539 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -311,7 +311,7 @@ print_eprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - if (print_probe_args(s, tp->args, tp->nr_args, + if (trace_probe_print_args(s, tp->args, tp->nr_args, (u8 *)&field[1], field) < 0) goto out; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index ee77c8203bd5..086e1e14f89e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1424,7 +1424,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - if (print_probe_args(s, tp->args, tp->nr_args, + if (trace_probe_print_args(s, tp->args, tp->nr_args, (u8 *)&field[1], field) < 0) goto out; @@ -1459,7 +1459,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - if (print_probe_args(s, tp->args, tp->nr_args, + if (trace_probe_print_args(s, tp->args, tp->nr_args, (u8 *)&field[1], field) < 0) goto out; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 11008c098727..20d0c4a97633 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1239,3 +1239,30 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char return ret; } + +int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, + u8 *data, void *field) +{ + void *p; + int i, j; + + for (i = 0; i < nr_args; i++) { + struct probe_arg *a = args + i; + + trace_seq_printf(s, " %s=", a->name); + if (likely(!a->count)) { + if (!a->type->print(s, data + a->offset, field)) + return -ENOMEM; + continue; + } + trace_seq_putc(s, '{'); + p = data + a->offset; + for (j = 0; j < a->count; j++) { + if (!a->type->print(s, p, field)) + return -ENOMEM; + trace_seq_putc(s, j == a->count - 1 ? '}' : ','); + p += a->type->size; + } + } + return 0; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index b4f99553411e..ef8ed3b65d05 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -349,6 +349,8 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b); bool trace_probe_match_command_args(struct trace_probe *tp, int argc, const char **argv); int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)); +int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, + u8 *data, void *field); #define trace_probe_for_each_link(pos, tp) \ list_for_each_entry(pos, &(tp)->event->files, list) diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index 5cea672243f6..bd3e755434eb 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -253,31 +253,3 @@ store_trace_args(void *data, struct trace_probe *tp, void *rec, } } } - -static inline int -print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, - u8 *data, void *field) -{ - void *p; - int i, j; - - for (i = 0; i < nr_args; i++) { - struct probe_arg *a = args + i; - - trace_seq_printf(s, " %s=", a->name); - if (likely(!a->count)) { - if (!a->type->print(s, data + a->offset, field)) - return -ENOMEM; - continue; - } - trace_seq_putc(s, '{'); - p = data + a->offset; - for (j = 0; j < a->count; j++) { - if (!a->type->print(s, p, field)) - return -ENOMEM; - trace_seq_putc(s, j == a->count - 1 ? '}' : ','); - p += a->type->size; - } - } - return 0; -} diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 8d64b6553aed..a39018a0660a 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1042,7 +1042,7 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e data = DATAOF_TRACE_ENTRY(entry, false); } - if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) + if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) goto out; trace_seq_putc(s, '\n'); From 672a2bf84061f0f19acfc5869f5b3689759a55a8 Mon Sep 17 00:00:00 2001 From: Song Chen Date: Fri, 30 Dec 2022 14:33:38 +0800 Subject: [PATCH 2/3] kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h There are 6 function definitions in trace_probe_tmpl.h, they are: 1, fetch_store_strlen 2, fetch_store_string 3, fetch_store_strlen_user 4, fetch_store_string_user 5, probe_mem_read 6, probe_mem_read_user Every C file which includes trace_probe_tmpl.h has to implement them, otherwise it gets warnings and errors. However, some of them are identical, like kprobe and eprobe, as a result, there is a lot redundant code in those 2 files. This patch would like to provide default behaviors for those functions which kprobe and eprobe can share by just including trace_probe_kernel.h with trace_probe_tmpl.h together. It removes redundant code, increases readability, and more importantly, makes it easier to introduce a new feature based on trace probe (it's possible). Link: https://lore.kernel.org/all/1672382018-18347-1-git-send-email-chensong_2000@189.cn/ Signed-off-by: Song Chen Reported-by: kernel test robot Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_eprobe.c | 55 ++----------------------------- kernel/trace/trace_events_synth.c | 6 ++-- kernel/trace/trace_kprobe.c | 54 ------------------------------ kernel/trace/trace_probe_kernel.h | 30 +++++++++++++---- 4 files changed, 29 insertions(+), 116 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 9d0ebcffb539..846546395d62 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -320,7 +320,8 @@ print_eprobe_event(struct trace_iterator *iter, int flags, return trace_handle_return(s); } -static unsigned long get_event_field(struct fetch_insn *code, void *rec) +static nokprobe_inline unsigned long +get_event_field(struct fetch_insn *code, void *rec) { struct ftrace_event_field *field = code->data; unsigned long val; @@ -454,58 +455,6 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, } NOKPROBE_SYMBOL(process_fetch_insn) -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen_user(unsigned long addr) -{ - return kern_fetch_store_strlen_user(addr); -} - -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen(unsigned long addr) -{ - return kern_fetch_store_strlen(addr); -} - -/* - * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf - * with max length and relative data location. - */ -static nokprobe_inline int -fetch_store_string_user(unsigned long addr, void *dest, void *base) -{ - return kern_fetch_store_string_user(addr, dest, base); -} - -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max - * length and relative data location. - */ -static nokprobe_inline int -fetch_store_string(unsigned long addr, void *dest, void *base) -{ - return kern_fetch_store_string(addr, dest, base); -} - -static nokprobe_inline int -probe_mem_read_user(void *dest, void *src, size_t size) -{ - const void __user *uaddr = (__force const void __user *)src; - - return copy_from_user_nofault(dest, uaddr, size); -} - -static nokprobe_inline int -probe_mem_read(void *dest, void *src, size_t size) -{ -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if ((unsigned long)src < TASK_SIZE) - return probe_mem_read_user(dest, src, size); -#endif - return copy_from_kernel_nofault(dest, src, size); -} - /* eprobe handler */ static inline void __eprobe_trace_func(struct eprobe_data *edata, void *rec) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 67592eed0be8..76590f50930c 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -420,12 +420,12 @@ static unsigned int trace_string(struct synth_trace_event *entry, data_offset += event->n_u64 * sizeof(u64); data_offset += data_size; - len = kern_fetch_store_strlen((unsigned long)str_val); + len = fetch_store_strlen((unsigned long)str_val); data_offset |= len << 16; *(u32 *)&entry->fields[*n_u64] = data_offset; - ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry); + ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry); (*n_u64)++; } else { @@ -473,7 +473,7 @@ static notrace void trace_event_raw_event_synth(void *__data, val_idx = var_ref_idx[field_pos]; str_val = (char *)(long)var_ref_vals[val_idx]; - len = kern_fetch_store_strlen((unsigned long)str_val); + len = fetch_store_strlen((unsigned long)str_val); fields_size += len; } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 086e1e14f89e..d32c6244ef99 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1218,60 +1218,6 @@ static const struct file_operations kprobe_profile_ops = { .release = seq_release, }; -/* Kprobe specific fetch functions */ - -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen_user(unsigned long addr) -{ - return kern_fetch_store_strlen_user(addr); -} - -/* Return the length of string -- including null terminal byte */ -static nokprobe_inline int -fetch_store_strlen(unsigned long addr) -{ - return kern_fetch_store_strlen(addr); -} - -/* - * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf - * with max length and relative data location. - */ -static nokprobe_inline int -fetch_store_string_user(unsigned long addr, void *dest, void *base) -{ - return kern_fetch_store_string_user(addr, dest, base); -} - -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max - * length and relative data location. - */ -static nokprobe_inline int -fetch_store_string(unsigned long addr, void *dest, void *base) -{ - return kern_fetch_store_string(addr, dest, base); -} - -static nokprobe_inline int -probe_mem_read_user(void *dest, void *src, size_t size) -{ - const void __user *uaddr = (__force const void __user *)src; - - return copy_from_user_nofault(dest, uaddr, size); -} - -static nokprobe_inline int -probe_mem_read(void *dest, void *src, size_t size) -{ -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - if ((unsigned long)src < TASK_SIZE) - return probe_mem_read_user(dest, src, size); -#endif - return copy_from_kernel_nofault(dest, src, size); -} - /* Note that we don't verify it, since the code does not come from user space */ static int process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, diff --git a/kernel/trace/trace_probe_kernel.h b/kernel/trace/trace_probe_kernel.h index 77dbd9ff9782..c4e1d4c03a85 100644 --- a/kernel/trace/trace_probe_kernel.h +++ b/kernel/trace/trace_probe_kernel.h @@ -12,7 +12,7 @@ */ /* Return the length of string -- including null terminal byte */ static nokprobe_inline int -kern_fetch_store_strlen_user(unsigned long addr) +fetch_store_strlen_user(unsigned long addr) { const void __user *uaddr = (__force const void __user *)addr; int ret; @@ -29,14 +29,14 @@ kern_fetch_store_strlen_user(unsigned long addr) /* Return the length of string -- including null terminal byte */ static nokprobe_inline int -kern_fetch_store_strlen(unsigned long addr) +fetch_store_strlen(unsigned long addr) { int ret, len = 0; u8 c; #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if (addr < TASK_SIZE) - return kern_fetch_store_strlen_user(addr); + return fetch_store_strlen_user(addr); #endif do { @@ -63,7 +63,7 @@ static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void * with max length and relative data location. */ static nokprobe_inline int -kern_fetch_store_string_user(unsigned long addr, void *dest, void *base) +fetch_store_string_user(unsigned long addr, void *dest, void *base) { const void __user *uaddr = (__force const void __user *)addr; int maxlen = get_loc_len(*(u32 *)dest); @@ -86,7 +86,7 @@ kern_fetch_store_string_user(unsigned long addr, void *dest, void *base) * length and relative data location. */ static nokprobe_inline int -kern_fetch_store_string(unsigned long addr, void *dest, void *base) +fetch_store_string(unsigned long addr, void *dest, void *base) { int maxlen = get_loc_len(*(u32 *)dest); void *__dest; @@ -94,7 +94,7 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base) #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if ((unsigned long)addr < TASK_SIZE) - return kern_fetch_store_string_user(addr, dest, base); + return fetch_store_string_user(addr, dest, base); #endif if (unlikely(!maxlen)) @@ -112,4 +112,22 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base) return ret; } +static nokprobe_inline int +probe_mem_read_user(void *dest, void *src, size_t size) +{ + const void __user *uaddr = (__force const void __user *)src; + + return copy_from_user_nofault(dest, uaddr, size); +} + +static nokprobe_inline int +probe_mem_read(void *dest, void *src, size_t size) +{ +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if ((unsigned long)src < TASK_SIZE) + return probe_mem_read_user(dest, src, size); +#endif + return copy_from_kernel_nofault(dest, src, size); +} + #endif /* __TRACE_PROBE_KERNEL_H_ */ From bd78acc89d4147aa4897a4c43e2a74c7df999b12 Mon Sep 17 00:00:00 2001 From: Song Chen Date: Fri, 30 Dec 2022 14:33:53 +0800 Subject: [PATCH 3/3] kernel/trace: extract common part in process_fetch_insn Each probe has an instance of process_fetch_insn respectively, but they have something in common. This patch aims to extract the common part into process_common_fetch_insn which can be shared by each probe, and they only need to focus on their special cases. Signed-off-by: Song Chen Suggested-by: Masami Hiramatsu Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu --- kernel/trace/trace_eprobe.c | 26 ++++++-------------------- kernel/trace/trace_kprobe.c | 14 ++++---------- kernel/trace/trace_probe_tmpl.h | 20 ++++++++++++++++++++ kernel/trace/trace_uprobe.c | 11 ++++------- 4 files changed, 34 insertions(+), 37 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 846546395d62..67e854979d53 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -396,20 +396,12 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec) case FETCH_OP_TP_ARG: val = get_event_field(code, rec); break; - case FETCH_OP_IMM: - val = code->immediate; - break; - case FETCH_OP_COMM: - val = (unsigned long)current->comm; - break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; case FETCH_NOP_SYMBOL: /* Ignore a place holder */ code++; goto retry; default: - continue; + if (process_common_fetch_insn(code, &val) < 0) + continue; } code++; len = process_fetch_insn_bottom(code, val, NULL, NULL); @@ -429,26 +421,20 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, void *base) { unsigned long val; + int ret; retry: switch (code->op) { case FETCH_OP_TP_ARG: val = get_event_field(code, rec); break; - case FETCH_OP_IMM: - val = code->immediate; - break; - case FETCH_OP_COMM: - val = (unsigned long)current->comm; - break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; case FETCH_NOP_SYMBOL: /* Ignore a place holder */ code++; goto retry; default: - return -EILSEQ; + ret = process_common_fetch_insn(code, &val); + if (ret < 0) + return ret; } code++; return process_fetch_insn_bottom(code, val, dest, base); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index d32c6244ef99..59cda19a9033 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1225,6 +1225,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, { struct pt_regs *regs = rec; unsigned long val; + int ret; retry: /* 1st stage: get value from context */ @@ -1241,15 +1242,6 @@ retry: case FETCH_OP_RETVAL: val = regs_return_value(regs); break; - case FETCH_OP_IMM: - val = code->immediate; - break; - case FETCH_OP_COMM: - val = (unsigned long)current->comm; - break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API case FETCH_OP_ARG: val = regs_get_kernel_argument(regs, code->param); @@ -1259,7 +1251,9 @@ retry: code++; goto retry; default: - return -EILSEQ; + ret = process_common_fetch_insn(code, &val); + if (ret < 0) + return ret; } code++; diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index bd3e755434eb..00707630788d 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -98,6 +98,26 @@ fetch_store_symstring(unsigned long addr, void *dest, void *base) return sprint_symbol(__dest, addr); } +/* common part of process_fetch_insn*/ +static nokprobe_inline int +process_common_fetch_insn(struct fetch_insn *code, unsigned long *val) +{ + switch (code->op) { + case FETCH_OP_IMM: + *val = code->immediate; + break; + case FETCH_OP_COMM: + *val = (unsigned long)current->comm; + break; + case FETCH_OP_DATA: + *val = (unsigned long)code->data; + break; + default: + return -EILSEQ; + } + return 0; +} + /* From the 2nd stage, routine is same */ static nokprobe_inline int process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val, diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index a39018a0660a..8b92e34ff0c8 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -220,6 +220,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, { struct pt_regs *regs = rec; unsigned long val; + int ret; /* 1st stage: get value from context */ switch (code->op) { @@ -235,20 +236,16 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, case FETCH_OP_RETVAL: val = regs_return_value(regs); break; - case FETCH_OP_IMM: - val = code->immediate; - break; case FETCH_OP_COMM: val = FETCH_TOKEN_COMM; break; - case FETCH_OP_DATA: - val = (unsigned long)code->data; - break; case FETCH_OP_FOFFS: val = translate_user_vaddr(code->immediate); break; default: - return -EILSEQ; + ret = process_common_fetch_insn(code, &val); + if (ret < 0) + return ret; } code++;