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-rw-r--r--Documentation/trace/kprobetrace.rst10
-rw-r--r--kernel/trace/trace.c4
-rw-r--r--kernel/trace/trace_kprobe.c18
-rw-r--r--kernel/trace/trace_probe.c36
-rw-r--r--kernel/trace/trace_probe.h9
-rw-r--r--kernel/trace/trace_uprobe.c2
6 files changed, 55 insertions, 24 deletions
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index 2dfed7a1ea6f..47e765c2f2c3 100644
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -45,16 +45,18 @@ Synopsis of kprobe_events
@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
$stackN : Fetch Nth entry of stack (N >= 0)
$stack : Fetch stack address.
- $retval : Fetch return value.(*)
+ $argN : Fetch the Nth function argument. (N >= 1) (\*1)
+ $retval : Fetch return value.(\*2)
$comm : Fetch current task comm.
- +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
+ +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(\*3)
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
(u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types
(x8/x16/x32/x64), "string" and bitfield are supported.
- (*) only for return probe.
- (**) this is useful for fetching a field of data structures.
+ (\*1) only for the probe on function entry (offs == 0).
+ (\*2) only for return probe.
+ (\*3) this is useful for fetching a field of data structures.
Types
-----
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e7f99f513959..ec5b21778806 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4625,7 +4625,11 @@ static const char readme_msg[] =
#endif
"\t args: <name>=fetcharg[:type]\n"
"\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+ "\t $stack<index>, $stack, $retval, $comm, $arg<N>\n"
+#else
"\t $stack<index>, $stack, $retval, $comm\n"
+#endif
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
"\t b<bit-width>@<bit-offset>/<container-size>,\n"
"\t <type>\\[<array-size>\\]\n"
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index fdd43f2f1fd1..3faaadbddf54 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -533,13 +533,15 @@ static int create_trace_kprobe(int argc, char **argv)
long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
+ unsigned int flags = TPARG_FL_KERNEL;
/* argc must be >= 1 */
if (argv[0][0] == 'p')
is_return = false;
- else if (argv[0][0] == 'r')
+ else if (argv[0][0] == 'r') {
is_return = true;
- else if (argv[0][0] == '-')
+ flags |= TPARG_FL_RETURN;
+ } else if (argv[0][0] == '-')
is_delete = true;
else {
pr_info("Probe definition must be started with 'p', 'r' or"
@@ -625,8 +627,9 @@ static int create_trace_kprobe(int argc, char **argv)
pr_info("Failed to parse either an address or a symbol.\n");
return ret;
}
- if (offset && is_return &&
- !kprobe_on_func_entry(NULL, symbol, offset)) {
+ if (kprobe_on_func_entry(NULL, symbol, offset))
+ flags |= TPARG_FL_FENTRY;
+ if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
pr_info("Given offset is not valid for return probe.\n");
return -EINVAL;
}
@@ -696,7 +699,7 @@ static int create_trace_kprobe(int argc, char **argv)
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
- is_return, true);
+ flags);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
@@ -932,6 +935,11 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
case FETCH_OP_COMM:
val = (unsigned long)current->comm;
break;
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+ case FETCH_OP_ARG:
+ val = regs_get_kernel_argument(regs, code->param);
+ break;
+#endif
default:
return -EILSEQ;
}
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index dfd096031305..333cda6d2633 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -157,14 +157,13 @@ int traceprobe_split_symbol_offset(char *symbol, 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_insn *code, bool is_return,
- bool is_kprobe)
+ struct fetch_insn *code, unsigned int flags)
{
int ret = 0;
unsigned long param;
if (strcmp(arg, "retval") == 0) {
- if (is_return)
+ if (flags & TPARG_FL_RETURN)
code->op = FETCH_OP_RETVAL;
else
ret = -EINVAL;
@@ -173,7 +172,8 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
code->op = FETCH_OP_STACKP;
} else if (isdigit(arg[5])) {
ret = kstrtoul(arg + 5, 10, &param);
- if (ret || (is_kprobe && param > PARAM_MAX_STACK))
+ if (ret || ((flags & TPARG_FL_KERNEL) &&
+ param > PARAM_MAX_STACK))
ret = -EINVAL;
else {
code->op = FETCH_OP_STACK;
@@ -183,6 +183,18 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
ret = -EINVAL;
} else if (strcmp(arg, "comm") == 0) {
code->op = FETCH_OP_COMM;
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+ } else if (((flags & TPARG_FL_MASK) ==
+ (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
+ strncmp(arg, "arg", 3) == 0) {
+ if (!isdigit(arg[3]))
+ return -EINVAL;
+ ret = kstrtoul(arg + 3, 10, &param);
+ if (ret || !param || param > PARAM_MAX_STACK)
+ return -EINVAL;
+ code->op = FETCH_OP_ARG;
+ code->param = (unsigned int)param - 1;
+#endif
} else
ret = -EINVAL;
@@ -193,7 +205,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
struct fetch_insn **pcode, struct fetch_insn *end,
- bool is_return, bool is_kprobe)
+ unsigned int flags)
{
struct fetch_insn *code = *pcode;
unsigned long param;
@@ -203,8 +215,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
switch (arg[0]) {
case '$':
- ret = parse_probe_vars(arg + 1, type, code,
- is_return, is_kprobe);
+ ret = parse_probe_vars(arg + 1, type, code, flags);
break;
case '%': /* named register */
@@ -226,7 +237,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->immediate = param;
} else if (arg[1] == '+') {
/* kprobes don't support file offsets */
- if (is_kprobe)
+ if (flags & TPARG_FL_KERNEL)
return -EINVAL;
ret = kstrtol(arg + 2, 0, &offset);
@@ -237,7 +248,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->immediate = (unsigned long)offset; // imm64?
} else {
/* uprobes don't support symbols */
- if (!is_kprobe)
+ if (!(flags & TPARG_FL_KERNEL))
return -EINVAL;
ret = traceprobe_split_symbol_offset(arg + 1, &offset);
@@ -278,8 +289,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
const struct fetch_type *t2 = find_fetch_type(NULL);
*tmp = '\0';
- ret = parse_probe_arg(arg, t2, &code, end, is_return,
- is_kprobe);
+ ret = parse_probe_arg(arg, t2, &code, end, flags);
if (ret)
break;
if (code->op == FETCH_OP_COMM)
@@ -339,7 +349,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
/* String length checking wrapper */
int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
- struct probe_arg *parg, bool is_return, bool is_kprobe)
+ struct probe_arg *parg, unsigned int flags)
{
struct fetch_insn *code, *scode, *tmp = NULL;
char *t, *t2;
@@ -397,7 +407,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
- is_return, is_kprobe);
+ flags);
if (ret)
goto fail;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 1f456fd82483..09f62171cc23 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -23,6 +23,7 @@
#include <linux/stringify.h>
#include <linux/limits.h>
#include <linux/uaccess.h>
+#include <linux/bitops.h>
#include <asm/bitsperlong.h>
#include "trace.h"
@@ -86,6 +87,7 @@ enum fetch_op {
FETCH_OP_RETVAL, /* Return value */
FETCH_OP_IMM, /* Immediate : .immediate */
FETCH_OP_COMM, /* Current comm */
+ FETCH_OP_ARG, /* Function argument : .param */
FETCH_OP_FOFFS, /* File offset: .immediate */
// Stage 2 (dereference) op
FETCH_OP_DEREF, /* Dereference: .offset */
@@ -263,8 +265,13 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
return NULL;
}
+#define TPARG_FL_RETURN BIT(0)
+#define TPARG_FL_KERNEL BIT(1)
+#define TPARG_FL_FENTRY BIT(2)
+#define TPARG_FL_MASK GENMASK(2, 0)
+
extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
- struct probe_arg *parg, bool is_return, bool is_kprobe);
+ struct probe_arg *parg, unsigned int flags);
extern int traceprobe_conflict_field_name(const char *name,
struct probe_arg *args, int narg);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 7154473ffaa4..394b93572506 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -557,7 +557,7 @@ static int create_trace_uprobe(int argc, char **argv)
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
- is_return, false);
+ is_return ? TPARG_FL_RETURN : 0);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-14 04:03:20 +0000