diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-05-15 14:38:30 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-05-25 23:04:42 -0400 |
| commit | 88903c464321cdbc2d473c24cbf311f576cf05bc (patch) | |
| tree | 79d0b37b1ac3b805d67651687f9ca866e5df059a /kernel/trace/trace_probe.c | |
| parent | 3d7081822f7f9eab867d9bcc8fd635208ec438e0 (diff) | |
tracing/probe: Add ustring type for user-space string
Add "ustring" type for fetching user-space string from kprobe event.
User can specify ustring type at uprobe event, and it is same as
"string" for uprobe.
Note that probe-event provides this option but it doesn't choose the
correct type automatically since we have not way to decide the address
is in user-space or not on some arch (and on some other arch, you can
fetch the string by "string" type). So user must carefully check the
target code (e.g. if you see __user on the target variable) and
use this new type.
Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_probe.c')
| -rw-r--r-- | kernel/trace/trace_probe.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index a347faced959..5a0470f7b9de 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -78,6 +78,8 @@ static const struct fetch_type probe_fetch_types[] = { /* Special types */ __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, "__data_loc char[]"), + __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, + "__data_loc char[]"), /* Basic types */ ASSIGN_FETCH_TYPE(u8, u8, 0), ASSIGN_FETCH_TYPE(u16, u16, 0), @@ -569,7 +571,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, goto fail; /* Store operation */ - if (!strcmp(parg->type->name, "string")) { + if (!strcmp(parg->type->name, "string") || + !strcmp(parg->type->name, "ustring")) { if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM) { trace_probe_log_err(offset + (t ? (t - arg) : 0), @@ -590,7 +593,11 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, goto fail; } } - code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ + /* If op == DEREF, replace it with STRING */ + if (!strcmp(parg->type->name, "ustring")) + code->op = FETCH_OP_ST_USTRING; + else + code->op = FETCH_OP_ST_STRING; code->size = parg->type->size; parg->dynamic = true; } else if (code->op == FETCH_OP_DEREF) { @@ -618,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, /* Loop(Array) operation */ if (parg->count) { if (scode->op != FETCH_OP_ST_MEM && - scode->op != FETCH_OP_ST_STRING) { + scode->op != FETCH_OP_ST_STRING && + scode->op != FETCH_OP_ST_USTRING) { trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_STRING); ret = -EINVAL; |