From patchwork Wed Dec 28 07:08:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Chen X-Patchwork-Id: 13082732 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CFFFC46467 for ; Wed, 28 Dec 2022 07:01:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230243AbiL1HBL (ORCPT ); Wed, 28 Dec 2022 02:01:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232081AbiL1HAr (ORCPT ); Wed, 28 Dec 2022 02:00:47 -0500 Received: from 189.cn (ptr.189.cn [183.61.185.104]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3102338F; Tue, 27 Dec 2022 23:00:45 -0800 (PST) HMM_SOURCE_IP: 10.64.8.41:60898.1416967110 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-123.150.8.42 (unknown [10.64.8.41]) by 189.cn (HERMES) with SMTP id 9B43F1002B3; Wed, 28 Dec 2022 15:00:41 +0800 (CST) Received: from ([123.150.8.42]) by gateway-153622-dep-79f476db8-8kzc7 with ESMTP id e2a796c87bf0415ca618d27dfe820380 for rostedt@goodmis.org; Wed, 28 Dec 2022 15:00:41 CST X-Transaction-ID: e2a796c87bf0415ca618d27dfe820380 X-Real-From: chensong_2000@189.cn X-Receive-IP: 123.150.8.42 X-MEDUSA-Status: 0 Sender: chensong_2000@189.cn From: Song Chen To: rostedt@goodmis.org, mhiramat@kernel.org, arnd@arndb.de Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Song Chen Subject: [PATCH v4 1/2] kernel/trace: Introduce trace_probe_print_args and use it in *probes Date: Wed, 28 Dec 2022 15:08:11 +0800 Message-Id: <1672211291-31439-1-git-send-email-chensong_2000@189.cn> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org 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. Signed-off-by: Song Chen Acked-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 5dd0617e5df6..bdb26eee7a0c 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -310,7 +310,7 @@ 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 5a75b039e586..a4ffa864dbb7 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1426,7 +1426,7 @@ 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; @@ -1461,7 +1461,7 @@ 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 36dff277de46..ae13b6b2d5da 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1218,3 +1218,30 @@ 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 de38f1c03776..cfef198013af 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -343,6 +343,8 @@ 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 b3bdb8ddb862..1b57420857e1 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -212,31 +212,3 @@ 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 fb58e86dd117..1ff8f87211a6 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1041,7 +1041,7 @@ 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 patchwork Wed Dec 28 07:08:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Chen X-Patchwork-Id: 13082733 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C42C1C3DA7A for ; Wed, 28 Dec 2022 07:01:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231736AbiL1HBM (ORCPT ); Wed, 28 Dec 2022 02:01:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232272AbiL1HA7 (ORCPT ); Wed, 28 Dec 2022 02:00:59 -0500 Received: from 189.cn (ptr.189.cn [183.61.185.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F26B62B0; Tue, 27 Dec 2022 23:00:56 -0800 (PST) HMM_SOURCE_IP: 10.64.8.31:60298.401377448 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-123.150.8.42 (unknown [10.64.8.31]) by 189.cn (HERMES) with SMTP id 2517B10029D; Wed, 28 Dec 2022 15:00:55 +0800 (CST) Received: from ([123.150.8.42]) by gateway-153622-dep-79f476db8-srhz2 with ESMTP id 9b7ed7b5b3124d83b36a3212303ad65b for rostedt@goodmis.org; Wed, 28 Dec 2022 15:00:56 CST X-Transaction-ID: 9b7ed7b5b3124d83b36a3212303ad65b X-Real-From: chensong_2000@189.cn X-Receive-IP: 123.150.8.42 X-MEDUSA-Status: 0 Sender: chensong_2000@189.cn From: Song Chen To: rostedt@goodmis.org, mhiramat@kernel.org, arnd@arndb.de Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Song Chen Subject: [PATCH v4 2/2] kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h Date: Wed, 28 Dec 2022 15:08:25 +0800 Message-Id: <1672211305-31482-1-git-send-email-chensong_2000@189.cn> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org There are 7 function definitions in trace_probe_tmpl.h, they are: 1, process_fetch_insn 2, fetch_store_strlen 3, fetch_store_string 4, fetch_store_strlen_user 5, fetch_store_string_user 6, probe_mem_read 7, 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). Signed-off-by: Song Chen Reported-by: kernel test robot --- v2: 1, reorganize patchset v3: 1, mark nokprobe_inline for get_event_field 2, remove warnings reported from kernel test robot 3, fix errors reported from kernel test robot v4: 1, reset changes in v3(2) and v3(3), they are not reasonable fix. 2, I intended to introduce a new header file to exclude trace_events_synth.c out of the patch. However, after looking further, i found the errors in [1] are introduced by this patch, but the warning in [1] are not. The errors can be fixed by adding "#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API". [1]:https://lore.kernel.org/lkml/202211301946.pkLE4PDp-lkp@intel.com/ --- kernel/trace/trace_eprobe.c | 144 ------------------------------ kernel/trace/trace_events_synth.c | 7 +- kernel/trace/trace_kprobe.c | 102 --------------------- kernel/trace/trace_probe_kernel.h | 143 +++++++++++++++++++++++++++-- 4 files changed, 141 insertions(+), 255 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index bdb26eee7a0c..60ced4a7a25d 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -319,64 +319,6 @@ 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) -{ - struct ftrace_event_field *field = code->data; - unsigned long val; - void *addr; - - addr = rec + field->offset; - - if (is_string_field(field)) { - switch (field->filter_type) { - case FILTER_DYN_STRING: - val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff)); - break; - case FILTER_RDYN_STRING: - val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff)); - break; - case FILTER_STATIC_STRING: - val = (unsigned long)addr; - break; - case FILTER_PTR_STRING: - val = (unsigned long)(*(char *)addr); - break; - default: - WARN_ON_ONCE(1); - return 0; - } - return val; - } - - switch (field->size) { - case 1: - if (field->is_signed) - val = *(char *)addr; - else - val = *(unsigned char *)addr; - break; - case 2: - if (field->is_signed) - val = *(short *)addr; - else - val = *(unsigned short *)addr; - break; - case 4: - if (field->is_signed) - val = *(int *)addr; - else - val = *(unsigned int *)addr; - break; - default: - if (field->is_signed) - val = *(long *)addr; - else - val = *(unsigned long *)addr; - break; - } - return val; -} - static int get_eprobe_size(struct trace_probe *tp, void *rec) { struct fetch_insn *code; @@ -419,92 +361,6 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec) return ret; } -/* Kprobe specific fetch functions */ - -/* 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, - void *base) -{ - unsigned long val; - - 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; - } - code++; - return process_fetch_insn_bottom(code, val, dest, base); -} -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 e310052dc83c..7460f18ba973 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -18,6 +18,7 @@ #include #include #include "trace_probe.h" +#include "trace_probe_tmpl.h" #include "trace_probe_kernel.h" #include "trace_synth.h" @@ -420,12 +421,12 @@ 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 +474,7 @@ 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 a4ffa864dbb7..c2e0b741ae82 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1218,108 +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, - void *base) -{ - struct pt_regs *regs = rec; - unsigned long val; - -retry: - /* 1st stage: get value from context */ - switch (code->op) { - case FETCH_OP_REG: - val = regs_get_register(regs, code->param); - break; - case FETCH_OP_STACK: - val = regs_get_kernel_stack_nth(regs, code->param); - break; - case FETCH_OP_STACKP: - val = kernel_stack_pointer(regs); - break; - 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); - break; -#endif - case FETCH_NOP_SYMBOL: /* Ignore a place holder */ - code++; - goto retry; - default: - return -EILSEQ; - } - code++; - - return process_fetch_insn_bottom(code, val, dest, base); -} -NOKPROBE_SYMBOL(process_fetch_insn) /* Kprobe handler */ static nokprobe_inline void diff --git a/kernel/trace/trace_probe_kernel.h b/kernel/trace/trace_probe_kernel.h index 77dbd9ff9782..39f44513ec4e 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 +112,135 @@ 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); +} + +static nokprobe_inline unsigned long +get_event_field(struct fetch_insn *code, void *rec) +{ + struct ftrace_event_field *field = code->data; + unsigned long val; + void *addr; + + addr = rec + field->offset; + + if (is_string_field(field)) { + switch (field->filter_type) { + case FILTER_DYN_STRING: + val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_RDYN_STRING: + val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_STATIC_STRING: + val = (unsigned long)addr; + break; + case FILTER_PTR_STRING: + val = (unsigned long)(*(char *)addr); + break; + default: + WARN_ON_ONCE(1); + return 0; + } + return val; + } + + switch (field->size) { + case 1: + if (field->is_signed) + val = *(char *)addr; + else + val = *(unsigned char *)addr; + break; + case 2: + if (field->is_signed) + val = *(short *)addr; + else + val = *(unsigned short *)addr; + break; + case 4: + if (field->is_signed) + val = *(int *)addr; + else + val = *(unsigned int *)addr; + break; + default: + if (field->is_signed) + val = *(long *)addr; + else + val = *(unsigned long *)addr; + break; + } + return val; +} + +/* 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, + void *base) +{ + struct pt_regs *regs = rec; + unsigned long val; + +retry: + /* 1st stage: get value from context */ + switch (code->op) { +#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = regs_get_kernel_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = kernel_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; +#endif + 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); + break; +#endif + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + case FETCH_OP_TP_ARG: + val = get_event_field(code, rec); + break; + default: + return -EILSEQ; + } + code++; + + return process_fetch_insn_bottom(code, val, dest, base); +} +NOKPROBE_SYMBOL(process_fetch_insn) + #endif /* __TRACE_PROBE_KERNEL_H_ */