Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 12/13] tracing/uprobes: Add support for full argument access methods | Date | Wed, 31 Jul 2013 18:03:29 +0900 |
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From: Namhyung Kim <namhyung.kim@lge.com>
Enable to fetch other types of argument for the uprobes. IOW, we can access stack, memory, deref, bitfield and retval from uprobes now.
Original-patch-by: Hyeoncheol Lee <cheol.lee@lge.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- kernel/trace/trace_probe.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index a46c9fd494ff..8ad48ca4e344 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -318,7 +318,7 @@ fail: } /* Special function : only accept unsigned long */ -static __kprobes void fetch_stack_address(struct pt_regs *regs, +static __kprobes void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest, void *priv) { *(unsigned long *)dest = kernel_stack_pointer(regs); @@ -368,7 +368,8 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return) + struct fetch_param *f, bool is_return, + bool is_kprobe) { int ret = 0; unsigned long param; @@ -380,13 +381,18 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, ret = -EINVAL; } else if (strncmp(arg, "stack", 5) == 0) { if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) - f->fn = fetch_stack_address; - else - ret = -EINVAL; + if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR)) + return -EINVAL; + + if (is_kprobe) + f->fn = fetch_kernel_stack_address; + else { + f->fn = t->fetch[FETCH_MTD_stack]; + f->data = (void *)0; + } } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, ¶m); - if (ret || param > PARAM_MAX_STACK) + if (ret || (is_kprobe && param > PARAM_MAX_STACK)) ret = -EINVAL; else { f->fn = t->fetch[FETCH_MTD_stack]; @@ -410,17 +416,13 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, int ret; const struct fetch_type *ttbl; - ttbl = kprobes_fetch_type_table; + ttbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table; ret = 0; - /* Until uprobe_events supports only reg arguments */ - if (!is_kprobe && arg[0] != '%') - return -EINVAL; - switch (arg[0]) { case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return); + ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe); break; case '%': /* named register */ @@ -443,6 +445,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, } else { struct symbol_cache *sc; + /* uprobes don't support symbols */ + if (!is_kprobe) + return -EINVAL; + ret = traceprobe_split_symbol_offset(arg + 1, &offset); if (ret) break; @@ -554,7 +560,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, int ret; const struct fetch_type *ttbl; - ttbl = kprobes_fetch_type_table; + ttbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table; if (strlen(arg) > MAX_ARGSTR_LEN) { pr_info("Argument is too long.: %s\n", arg); -- 1.7.11.7
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