diff options
author | Namhyung Kim <namhyung.kim@lge.com> | 2013-11-25 04:42:47 (GMT) |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2014-01-03 01:57:05 (GMT) |
commit | b7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9 (patch) | |
tree | 0831ae7ab363f3789c5cb14bbf4973bfe17287bc /kernel | |
parent | 72fd293aa9ae8f4f48d6042be43fe81551c639f2 (diff) | |
download | linux-b7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9.tar.xz |
tracing/uprobes: Add @+file_offset fetch method
Enable to fetch data from a file offset. Currently it only supports
fetching from same binary uprobe set. It'll translate the file offset
to a proper virtual address in the process.
The syntax is "@+OFFSET" as it does similar to normal memory fetching
(@ADDR) which does no address translation.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/trace_kprobe.c | 8 | ||||
-rw-r--r-- | kernel/trace/trace_probe.c | 13 | ||||
-rw-r--r-- | kernel/trace/trace_probe.h | 2 | ||||
-rw-r--r-- | kernel/trace/trace_uprobe.c | 40 |
4 files changed, 62 insertions, 1 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f94a569..ce0ed8a 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -239,6 +239,14 @@ DEFINE_BASIC_FETCH_FUNCS(symbol) DEFINE_FETCH_symbol(string) DEFINE_FETCH_symbol(string_size) +/* kprobes don't support file_offset fetch methods */ +#define fetch_file_offset_u8 NULL +#define fetch_file_offset_u16 NULL +#define fetch_file_offset_u32 NULL +#define fetch_file_offset_u64 NULL +#define fetch_file_offset_string NULL +#define fetch_file_offset_string_size NULL + /* Fetch type information table */ const struct fetch_type kprobes_fetch_type_table[] = { /* Special types */ diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index a130d61..8364a42 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -374,7 +374,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, } break; - case '@': /* memory or symbol */ + case '@': /* memory, file-offset or symbol */ if (isdigit(arg[1])) { ret = kstrtoul(arg + 1, 0, ¶m); if (ret) @@ -382,6 +382,17 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, f->fn = t->fetch[FETCH_MTD_memory]; f->data = (void *)param; + } else if (arg[1] == '+') { + /* kprobes don't support file offsets */ + if (is_kprobe) + return -EINVAL; + + ret = kstrtol(arg + 2, 0, &offset); + if (ret) + break; + + f->fn = t->fetch[FETCH_MTD_file_offset]; + f->data = (void *)offset; } else { /* uprobes don't support symbols */ if (!is_kprobe) diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2d5b8f5..e29d743 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -106,6 +106,7 @@ enum { FETCH_MTD_symbol, FETCH_MTD_deref, FETCH_MTD_bitfield, + FETCH_MTD_file_offset, FETCH_MTD_END, }; @@ -217,6 +218,7 @@ ASSIGN_FETCH_FUNC(memory, ftype), \ ASSIGN_FETCH_FUNC(symbol, ftype), \ ASSIGN_FETCH_FUNC(deref, ftype), \ ASSIGN_FETCH_FUNC(bitfield, ftype), \ +ASSIGN_FETCH_FUNC(file_offset, ftype), \ } \ } diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 794e8bc..1fdea6d 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -70,6 +70,11 @@ static int unregister_uprobe_event(struct trace_uprobe *tu); static DEFINE_MUTEX(uprobe_lock); static LIST_HEAD(uprobe_list); +struct uprobe_dispatch_data { + struct trace_uprobe *tu; + unsigned long bp_addr; +}; + static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); static int uretprobe_dispatcher(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs); @@ -175,6 +180,29 @@ static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, #define fetch_symbol_string NULL #define fetch_symbol_string_size NULL +static unsigned long translate_user_vaddr(void *file_offset) +{ + unsigned long base_addr; + struct uprobe_dispatch_data *udd; + + udd = (void *) current->utask->vaddr; + + base_addr = udd->bp_addr - udd->tu->offset; + return base_addr + (unsigned long)file_offset; +} + +#define DEFINE_FETCH_file_offset(type) \ +static __kprobes void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,\ + void *offset, void *dest) \ +{ \ + void *vaddr = (void *)translate_user_vaddr(offset); \ + \ + FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \ +} +DEFINE_BASIC_FETCH_FUNCS(file_offset) +DEFINE_FETCH_file_offset(string) +DEFINE_FETCH_file_offset(string_size) + /* Fetch type information table */ const struct fetch_type uprobes_fetch_type_table[] = { /* Special types */ @@ -1106,11 +1134,17 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) { struct trace_uprobe *tu; + struct uprobe_dispatch_data udd; int ret = 0; tu = container_of(con, struct trace_uprobe, consumer); tu->nhit++; + udd.tu = tu; + udd.bp_addr = instruction_pointer(regs); + + current->utask->vaddr = (unsigned long) &udd; + if (tu->tp.flags & TP_FLAG_TRACE) ret |= uprobe_trace_func(tu, regs); @@ -1125,9 +1159,15 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) { struct trace_uprobe *tu; + struct uprobe_dispatch_data udd; tu = container_of(con, struct trace_uprobe, consumer); + udd.tu = tu; + udd.bp_addr = func; + + current->utask->vaddr = (unsigned long) &udd; + if (tu->tp.flags & TP_FLAG_TRACE) uretprobe_trace_func(tu, func, regs); |