Re: [RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
On Sat, 3 Nov 2018 13:43:16 -0400
Steven Rostedt wrote:
> On Sun, 4 Nov 2018 01:03:34 +0900
> Masami Hiramatsu wrote:
>
> > Introduce symbol_offset data structure for avoiding symbol+offset
> > parsing when updating arguments.
> >
> > For kprobe events, "@symbol+offset" is supported, that requires
> > to be updated when new module is loaded because @symbol address
> > can be solved at that point. Currently kprobe events saves
> > the "symbol+offset" string and parse it repeatedly, but that
> > is inefficient.
>
> Do we care if it's inefficient? It's only done on module load and at
> the beginning. That's far from a fast path.
>
> If anything, the original solution saves memory, which is a bigger
> concern than speed in this case.
OK, and original one saves lines too. Please drop it :)
Thank you,
>
> -- Steve
>
>
> > This introduces symbol_offset data structure which can save the
> > offset and symbol separated, so that we don't need to parse it
> > anymore.
> >
> > Signed-off-by: Masami Hiramatsu
> > ---
> > kernel/trace/trace_probe.c | 49
> > +---
> > kernel/trace/trace_probe.h |7 +-
> > 2 files changed, 34 insertions(+), 22 deletions(-)
> >
> > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> > index bd30e9398d2a..0a3af7d6e133 100644
> > --- a/kernel/trace/trace_probe.c
> > +++ b/kernel/trace/trace_probe.c
> > @@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
> > fetch_type *t,
> > return ret;
> > }
> >
> > +static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
> > +{
> > + int ret;
> > + long offset = 0;
> > + struct symbol_offset *sof;
> > +
> > + ret = traceprobe_split_symbol_offset(sym_offs_str, );
> > + if (ret)
> > + return ERR_PTR(ret);
> > +
> > + sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
> > + GFP_KERNEL);
> > + if (!sof)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + sof->offset = offset;
> > + strcpy(sof->symbol, sym_offs_str);
> > + return sof;
> > +}
> > +
> > /* Recursive argument parser */
> > static int
> > parse_probe_arg(char *arg, const struct fetch_type *type,
> > @@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type
> > *type,
> >
> > /* Preserve symbol for updating */
> > code->op = FETCH_NOP_SYMBOL;
> > - code->data = kstrdup(arg + 1, GFP_KERNEL);
> > - if (!code->data)
> > - return -ENOMEM;
> > + code->symoffs = allocate_symbol_offset(arg + 1);
> > + if (IS_ERR(code->symoffs))
> > + return PTR_ERR(code->symoffs);
> > if (++code == end)
> > return -E2BIG;
> >
> > @@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> > if (ret) {
> > for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
> > if (code->op == FETCH_NOP_SYMBOL)
> > - kfree(code->data);
> > + kfree(code->symoffs);
> > }
> > kfree(tmp);
> >
> > @@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> >
> > while (code && code->op != FETCH_OP_END) {
> > if (code->op == FETCH_NOP_SYMBOL)
> > - kfree(code->data);
> > + kfree(code->symoffs);
> > code++;
> > }
> > kfree(arg->code);
> > @@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> > int traceprobe_update_arg(struct probe_arg *arg)
> > {
> > struct fetch_insn *code = arg->code;
> > - long offset;
> > - char *tmp;
> > - char c;
> > - int ret = 0;
> >
> > while (code && code->op != FETCH_OP_END) {
> > if (code->op == FETCH_NOP_SYMBOL) {
> > if (code[1].op != FETCH_OP_IMM)
> > return -EINVAL;
> >
> > - tmp = strpbrk(code->data, "+-");
> > - if (tmp)
> > - c = *tmp;
> > - ret = traceprobe_split_symbol_offset(code->data,
> > -);
> > - if (ret)
> > - return ret;
> > -
> > code[1].immediate =
> > - (unsigned long)kallsyms_lookup_name(code->data);
> > - if (tmp)
> > - *tmp = c;
> > + (unsigned long)kallsyms_lookup_name(
> > + code->symoffs->symbol);
> > if (!code[1].immediate)
> > return -ENOENT;
> > - code[1].immediate += offset;
> > + code[1].immediate += code->symoffs->offset;
> >
Re: [RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
On Sat, 3 Nov 2018 13:43:16 -0400
Steven Rostedt wrote:
> On Sun, 4 Nov 2018 01:03:34 +0900
> Masami Hiramatsu wrote:
>
> > Introduce symbol_offset data structure for avoiding symbol+offset
> > parsing when updating arguments.
> >
> > For kprobe events, "@symbol+offset" is supported, that requires
> > to be updated when new module is loaded because @symbol address
> > can be solved at that point. Currently kprobe events saves
> > the "symbol+offset" string and parse it repeatedly, but that
> > is inefficient.
>
> Do we care if it's inefficient? It's only done on module load and at
> the beginning. That's far from a fast path.
>
> If anything, the original solution saves memory, which is a bigger
> concern than speed in this case.
OK, and original one saves lines too. Please drop it :)
Thank you,
>
> -- Steve
>
>
> > This introduces symbol_offset data structure which can save the
> > offset and symbol separated, so that we don't need to parse it
> > anymore.
> >
> > Signed-off-by: Masami Hiramatsu
> > ---
> > kernel/trace/trace_probe.c | 49
> > +---
> > kernel/trace/trace_probe.h |7 +-
> > 2 files changed, 34 insertions(+), 22 deletions(-)
> >
> > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> > index bd30e9398d2a..0a3af7d6e133 100644
> > --- a/kernel/trace/trace_probe.c
> > +++ b/kernel/trace/trace_probe.c
> > @@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
> > fetch_type *t,
> > return ret;
> > }
> >
> > +static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
> > +{
> > + int ret;
> > + long offset = 0;
> > + struct symbol_offset *sof;
> > +
> > + ret = traceprobe_split_symbol_offset(sym_offs_str, );
> > + if (ret)
> > + return ERR_PTR(ret);
> > +
> > + sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
> > + GFP_KERNEL);
> > + if (!sof)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + sof->offset = offset;
> > + strcpy(sof->symbol, sym_offs_str);
> > + return sof;
> > +}
> > +
> > /* Recursive argument parser */
> > static int
> > parse_probe_arg(char *arg, const struct fetch_type *type,
> > @@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type
> > *type,
> >
> > /* Preserve symbol for updating */
> > code->op = FETCH_NOP_SYMBOL;
> > - code->data = kstrdup(arg + 1, GFP_KERNEL);
> > - if (!code->data)
> > - return -ENOMEM;
> > + code->symoffs = allocate_symbol_offset(arg + 1);
> > + if (IS_ERR(code->symoffs))
> > + return PTR_ERR(code->symoffs);
> > if (++code == end)
> > return -E2BIG;
> >
> > @@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> > if (ret) {
> > for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
> > if (code->op == FETCH_NOP_SYMBOL)
> > - kfree(code->data);
> > + kfree(code->symoffs);
> > }
> > kfree(tmp);
> >
> > @@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> >
> > while (code && code->op != FETCH_OP_END) {
> > if (code->op == FETCH_NOP_SYMBOL)
> > - kfree(code->data);
> > + kfree(code->symoffs);
> > code++;
> > }
> > kfree(arg->code);
> > @@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> > int traceprobe_update_arg(struct probe_arg *arg)
> > {
> > struct fetch_insn *code = arg->code;
> > - long offset;
> > - char *tmp;
> > - char c;
> > - int ret = 0;
> >
> > while (code && code->op != FETCH_OP_END) {
> > if (code->op == FETCH_NOP_SYMBOL) {
> > if (code[1].op != FETCH_OP_IMM)
> > return -EINVAL;
> >
> > - tmp = strpbrk(code->data, "+-");
> > - if (tmp)
> > - c = *tmp;
> > - ret = traceprobe_split_symbol_offset(code->data,
> > -);
> > - if (ret)
> > - return ret;
> > -
> > code[1].immediate =
> > - (unsigned long)kallsyms_lookup_name(code->data);
> > - if (tmp)
> > - *tmp = c;
> > + (unsigned long)kallsyms_lookup_name(
> > + code->symoffs->symbol);
> > if (!code[1].immediate)
> > return -ENOENT;
> > - code[1].immediate += offset;
> > + code[1].immediate += code->symoffs->offset;
> >
Re: [RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
On Sun, 4 Nov 2018 01:03:34 +0900
Masami Hiramatsu wrote:
> Introduce symbol_offset data structure for avoiding symbol+offset
> parsing when updating arguments.
>
> For kprobe events, "@symbol+offset" is supported, that requires
> to be updated when new module is loaded because @symbol address
> can be solved at that point. Currently kprobe events saves
> the "symbol+offset" string and parse it repeatedly, but that
> is inefficient.
Do we care if it's inefficient? It's only done on module load and at
the beginning. That's far from a fast path.
If anything, the original solution saves memory, which is a bigger
concern than speed in this case.
-- Steve
> This introduces symbol_offset data structure which can save the
> offset and symbol separated, so that we don't need to parse it
> anymore.
>
> Signed-off-by: Masami Hiramatsu
> ---
> kernel/trace/trace_probe.c | 49
> +---
> kernel/trace/trace_probe.h |7 +-
> 2 files changed, 34 insertions(+), 22 deletions(-)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index bd30e9398d2a..0a3af7d6e133 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
> fetch_type *t,
> return ret;
> }
>
> +static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
> +{
> + int ret;
> + long offset = 0;
> + struct symbol_offset *sof;
> +
> + ret = traceprobe_split_symbol_offset(sym_offs_str, );
> + if (ret)
> + return ERR_PTR(ret);
> +
> + sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
> + GFP_KERNEL);
> + if (!sof)
> + return ERR_PTR(-ENOMEM);
> +
> + sof->offset = offset;
> + strcpy(sof->symbol, sym_offs_str);
> + return sof;
> +}
> +
> /* Recursive argument parser */
> static int
> parse_probe_arg(char *arg, const struct fetch_type *type,
> @@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
>
> /* Preserve symbol for updating */
> code->op = FETCH_NOP_SYMBOL;
> - code->data = kstrdup(arg + 1, GFP_KERNEL);
> - if (!code->data)
> - return -ENOMEM;
> + code->symoffs = allocate_symbol_offset(arg + 1);
> + if (IS_ERR(code->symoffs))
> + return PTR_ERR(code->symoffs);
> if (++code == end)
> return -E2BIG;
>
> @@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> if (ret) {
> for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
> if (code->op == FETCH_NOP_SYMBOL)
> - kfree(code->data);
> + kfree(code->symoffs);
> }
> kfree(tmp);
>
> @@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
>
> while (code && code->op != FETCH_OP_END) {
> if (code->op == FETCH_NOP_SYMBOL)
> - kfree(code->data);
> + kfree(code->symoffs);
> code++;
> }
> kfree(arg->code);
> @@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> int traceprobe_update_arg(struct probe_arg *arg)
> {
> struct fetch_insn *code = arg->code;
> - long offset;
> - char *tmp;
> - char c;
> - int ret = 0;
>
> while (code && code->op != FETCH_OP_END) {
> if (code->op == FETCH_NOP_SYMBOL) {
> if (code[1].op != FETCH_OP_IMM)
> return -EINVAL;
>
> - tmp = strpbrk(code->data, "+-");
> - if (tmp)
> - c = *tmp;
> - ret = traceprobe_split_symbol_offset(code->data,
> - );
> - if (ret)
> - return ret;
> -
> code[1].immediate =
> - (unsigned long)kallsyms_lookup_name(code->data);
> - if (tmp)
> - *tmp = c;
> + (unsigned long)kallsyms_lookup_name(
> + code->symoffs->symbol);
> if (!code[1].immediate)
> return -ENOENT;
> - code[1].immediate += offset;
> + code[1].immediate += code->symoffs->offset;
> }
> code++;
> }
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 974afc1a3e73..942424d05427 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -103,6 +103,11 @@ enum fetch_op {
Re: [RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
On Sun, 4 Nov 2018 01:03:34 +0900
Masami Hiramatsu wrote:
> Introduce symbol_offset data structure for avoiding symbol+offset
> parsing when updating arguments.
>
> For kprobe events, "@symbol+offset" is supported, that requires
> to be updated when new module is loaded because @symbol address
> can be solved at that point. Currently kprobe events saves
> the "symbol+offset" string and parse it repeatedly, but that
> is inefficient.
Do we care if it's inefficient? It's only done on module load and at
the beginning. That's far from a fast path.
If anything, the original solution saves memory, which is a bigger
concern than speed in this case.
-- Steve
> This introduces symbol_offset data structure which can save the
> offset and symbol separated, so that we don't need to parse it
> anymore.
>
> Signed-off-by: Masami Hiramatsu
> ---
> kernel/trace/trace_probe.c | 49
> +---
> kernel/trace/trace_probe.h |7 +-
> 2 files changed, 34 insertions(+), 22 deletions(-)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index bd30e9398d2a..0a3af7d6e133 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
> fetch_type *t,
> return ret;
> }
>
> +static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
> +{
> + int ret;
> + long offset = 0;
> + struct symbol_offset *sof;
> +
> + ret = traceprobe_split_symbol_offset(sym_offs_str, );
> + if (ret)
> + return ERR_PTR(ret);
> +
> + sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
> + GFP_KERNEL);
> + if (!sof)
> + return ERR_PTR(-ENOMEM);
> +
> + sof->offset = offset;
> + strcpy(sof->symbol, sym_offs_str);
> + return sof;
> +}
> +
> /* Recursive argument parser */
> static int
> parse_probe_arg(char *arg, const struct fetch_type *type,
> @@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
>
> /* Preserve symbol for updating */
> code->op = FETCH_NOP_SYMBOL;
> - code->data = kstrdup(arg + 1, GFP_KERNEL);
> - if (!code->data)
> - return -ENOMEM;
> + code->symoffs = allocate_symbol_offset(arg + 1);
> + if (IS_ERR(code->symoffs))
> + return PTR_ERR(code->symoffs);
> if (++code == end)
> return -E2BIG;
>
> @@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> if (ret) {
> for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
> if (code->op == FETCH_NOP_SYMBOL)
> - kfree(code->data);
> + kfree(code->symoffs);
> }
> kfree(tmp);
>
> @@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
>
> while (code && code->op != FETCH_OP_END) {
> if (code->op == FETCH_NOP_SYMBOL)
> - kfree(code->data);
> + kfree(code->symoffs);
> code++;
> }
> kfree(arg->code);
> @@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
> int traceprobe_update_arg(struct probe_arg *arg)
> {
> struct fetch_insn *code = arg->code;
> - long offset;
> - char *tmp;
> - char c;
> - int ret = 0;
>
> while (code && code->op != FETCH_OP_END) {
> if (code->op == FETCH_NOP_SYMBOL) {
> if (code[1].op != FETCH_OP_IMM)
> return -EINVAL;
>
> - tmp = strpbrk(code->data, "+-");
> - if (tmp)
> - c = *tmp;
> - ret = traceprobe_split_symbol_offset(code->data,
> - );
> - if (ret)
> - return ret;
> -
> code[1].immediate =
> - (unsigned long)kallsyms_lookup_name(code->data);
> - if (tmp)
> - *tmp = c;
> + (unsigned long)kallsyms_lookup_name(
> + code->symoffs->symbol);
> if (!code[1].immediate)
> return -ENOENT;
> - code[1].immediate += offset;
> + code[1].immediate += code->symoffs->offset;
> }
> code++;
> }
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 974afc1a3e73..942424d05427 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -103,6 +103,11 @@ enum fetch_op {
[RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
Introduce symbol_offset data structure for avoiding symbol+offset
parsing when updating arguments.
For kprobe events, "@symbol+offset" is supported, that requires
to be updated when new module is loaded because @symbol address
can be solved at that point. Currently kprobe events saves
the "symbol+offset" string and parse it repeatedly, but that
is inefficient.
This introduces symbol_offset data structure which can save the
offset and symbol separated, so that we don't need to parse it
anymore.
Signed-off-by: Masami Hiramatsu
---
kernel/trace/trace_probe.c | 49 +---
kernel/trace/trace_probe.h |7 +-
2 files changed, 34 insertions(+), 22 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index bd30e9398d2a..0a3af7d6e133 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
fetch_type *t,
return ret;
}
+static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
+{
+ int ret;
+ long offset = 0;
+ struct symbol_offset *sof;
+
+ ret = traceprobe_split_symbol_offset(sym_offs_str, );
+ if (ret)
+ return ERR_PTR(ret);
+
+ sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
+ GFP_KERNEL);
+ if (!sof)
+ return ERR_PTR(-ENOMEM);
+
+ sof->offset = offset;
+ strcpy(sof->symbol, sym_offs_str);
+ return sof;
+}
+
/* Recursive argument parser */
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
@@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
/* Preserve symbol for updating */
code->op = FETCH_NOP_SYMBOL;
- code->data = kstrdup(arg + 1, GFP_KERNEL);
- if (!code->data)
- return -ENOMEM;
+ code->symoffs = allocate_symbol_offset(arg + 1);
+ if (IS_ERR(code->symoffs))
+ return PTR_ERR(code->symoffs);
if (++code == end)
return -E2BIG;
@@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
if (ret) {
for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
if (code->op == FETCH_NOP_SYMBOL)
- kfree(code->data);
+ kfree(code->symoffs);
}
kfree(tmp);
@@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
while (code && code->op != FETCH_OP_END) {
if (code->op == FETCH_NOP_SYMBOL)
- kfree(code->data);
+ kfree(code->symoffs);
code++;
}
kfree(arg->code);
@@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
int traceprobe_update_arg(struct probe_arg *arg)
{
struct fetch_insn *code = arg->code;
- long offset;
- char *tmp;
- char c;
- int ret = 0;
while (code && code->op != FETCH_OP_END) {
if (code->op == FETCH_NOP_SYMBOL) {
if (code[1].op != FETCH_OP_IMM)
return -EINVAL;
- tmp = strpbrk(code->data, "+-");
- if (tmp)
- c = *tmp;
- ret = traceprobe_split_symbol_offset(code->data,
-);
- if (ret)
- return ret;
-
code[1].immediate =
- (unsigned long)kallsyms_lookup_name(code->data);
- if (tmp)
- *tmp = c;
+ (unsigned long)kallsyms_lookup_name(
+ code->symoffs->symbol);
if (!code[1].immediate)
return -ENOENT;
- code[1].immediate += offset;
+ code[1].immediate += code->symoffs->offset;
}
code++;
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 974afc1a3e73..942424d05427 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -103,6 +103,11 @@ enum fetch_op {
FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
};
+struct symbol_offset {
+ long offset;
+ char symbol[];
+};
+
struct fetch_insn {
enum fetch_op op;
union {
@@ -117,7 +122,7 @@ struct fetch_insn {
unsigned char rshift;
};
unsigned long immediate;
- void *data;
+
[RFC PATCH] tracing/kprobes: Avoid parsing symbol+offset when updating arguments
Introduce symbol_offset data structure for avoiding symbol+offset
parsing when updating arguments.
For kprobe events, "@symbol+offset" is supported, that requires
to be updated when new module is loaded because @symbol address
can be solved at that point. Currently kprobe events saves
the "symbol+offset" string and parse it repeatedly, but that
is inefficient.
This introduces symbol_offset data structure which can save the
offset and symbol separated, so that we don't need to parse it
anymore.
Signed-off-by: Masami Hiramatsu
---
kernel/trace/trace_probe.c | 49 +---
kernel/trace/trace_probe.h |7 +-
2 files changed, 34 insertions(+), 22 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index bd30e9398d2a..0a3af7d6e133 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -201,6 +201,26 @@ static int parse_probe_vars(char *arg, const struct
fetch_type *t,
return ret;
}
+static struct symbol_offset *allocate_symbol_offset(char *sym_offs_str)
+{
+ int ret;
+ long offset = 0;
+ struct symbol_offset *sof;
+
+ ret = traceprobe_split_symbol_offset(sym_offs_str, );
+ if (ret)
+ return ERR_PTR(ret);
+
+ sof = kzalloc(sizeof(struct symbol_offset) + strlen(sym_offs_str) + 1,
+ GFP_KERNEL);
+ if (!sof)
+ return ERR_PTR(-ENOMEM);
+
+ sof->offset = offset;
+ strcpy(sof->symbol, sym_offs_str);
+ return sof;
+}
+
/* Recursive argument parser */
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
@@ -253,9 +273,9 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
/* Preserve symbol for updating */
code->op = FETCH_NOP_SYMBOL;
- code->data = kstrdup(arg + 1, GFP_KERNEL);
- if (!code->data)
- return -ENOMEM;
+ code->symoffs = allocate_symbol_offset(arg + 1);
+ if (IS_ERR(code->symoffs))
+ return PTR_ERR(code->symoffs);
if (++code == end)
return -E2BIG;
@@ -483,7 +503,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
if (ret) {
for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
if (code->op == FETCH_NOP_SYMBOL)
- kfree(code->data);
+ kfree(code->symoffs);
}
kfree(tmp);
@@ -513,7 +533,7 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
while (code && code->op != FETCH_OP_END) {
if (code->op == FETCH_NOP_SYMBOL)
- kfree(code->data);
+ kfree(code->symoffs);
code++;
}
kfree(arg->code);
@@ -525,31 +545,18 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
int traceprobe_update_arg(struct probe_arg *arg)
{
struct fetch_insn *code = arg->code;
- long offset;
- char *tmp;
- char c;
- int ret = 0;
while (code && code->op != FETCH_OP_END) {
if (code->op == FETCH_NOP_SYMBOL) {
if (code[1].op != FETCH_OP_IMM)
return -EINVAL;
- tmp = strpbrk(code->data, "+-");
- if (tmp)
- c = *tmp;
- ret = traceprobe_split_symbol_offset(code->data,
-);
- if (ret)
- return ret;
-
code[1].immediate =
- (unsigned long)kallsyms_lookup_name(code->data);
- if (tmp)
- *tmp = c;
+ (unsigned long)kallsyms_lookup_name(
+ code->symoffs->symbol);
if (!code[1].immediate)
return -ENOENT;
- code[1].immediate += offset;
+ code[1].immediate += code->symoffs->offset;
}
code++;
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 974afc1a3e73..942424d05427 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -103,6 +103,11 @@ enum fetch_op {
FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
};
+struct symbol_offset {
+ long offset;
+ char symbol[];
+};
+
struct fetch_insn {
enum fetch_op op;
union {
@@ -117,7 +122,7 @@ struct fetch_insn {
unsigned char rshift;
};
unsigned long immediate;
- void *data;
+
