Commit 99fec39e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull kprobe fixes from Steven Rostedt:
 "The documentation for kprobe events says that symbol offets can take
  both a + and - sign to get to befor and after the symbol address.

  But in actuality, the code does not support the minus. This fixes that
  issue, and adds a few more selftests to kprobe events"

* tag 'trace-v4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests: ftrace: Add a testcase for probepoint
  selftests: ftrace: Add a testcase for string type with kprobe_event
  selftests: ftrace: Add probe event argument syntax testcase
  tracing: probeevent: Fix to support minus offset from symbol
parents 86d043d4 dfa453bc

kernel/trace/trace_kprobe.c

+2 −2
Original line number Diff line number Diff line
@@ -659,7 +659,7 @@ static int create_trace_kprobe(int argc, char **argv) 
	char *symbol = NULL, *event = NULL, *group = NULL;

	int maxactive = 0;

	char *arg;

	unsigned long offset = 0;

	long offset = 0;

	void *addr = NULL;

	char buf[MAX_EVENT_NAME_LEN];
@@ -747,7 +747,7 @@ static int create_trace_kprobe(int argc, char **argv) 
		symbol = argv[1];

		/* TODO: support .init module functions */

		ret = traceprobe_split_symbol_offset(symbol, &offset);

		if (ret) {

		if (ret || offset < 0 || offset > UINT_MAX) {

			pr_info("Failed to parse either an address or a symbol.\n");

			return ret;

		}

kernel/trace/trace_probe.c

+3 −5
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, 
}



/* Split symbol and offset. */

int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)

int traceprobe_split_symbol_offset(char *symbol, long *offset)

{

	char *tmp;

	int ret;
@@ -328,13 +328,11 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) 
	if (!offset)

		return -EINVAL;



	tmp = strchr(symbol, '+');

	tmp = strpbrk(symbol, "+-");

	if (tmp) {

		/* skip sign because kstrtoul doesn't accept '+' */

		ret = kstrtoul(tmp + 1, 0, offset);

		ret = kstrtol(tmp, 0, offset);

		if (ret)

			return ret;



		*tmp = '\0';

	} else

		*offset = 0;

kernel/trace/trace_probe.h

+1 −1
Original line number Diff line number Diff line
@@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, 
extern void traceprobe_update_arg(struct probe_arg *arg);

extern void traceprobe_free_probe_arg(struct probe_arg *arg);



extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);

extern int traceprobe_split_symbol_offset(char *symbol, long *offset);



/* Sum up total data length for dynamic arraies (strings) */

static nokprobe_inline int

tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc

0 → 100644
+46 −0
Original line number Diff line number Diff line 
#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Kprobe event string type argument



[ -f kprobe_events ] || exit_unsupported # this is configurable



echo 0 > events/enable

echo > kprobe_events



case `uname -m` in

x86_64)

  ARG2=%si

  OFFS=8

;;

i[3456]86)

  ARG2=%cx

  OFFS=4

;;

aarch64)

  ARG2=%x1

  OFFS=8

;;

arm*)

  ARG2=%r1

  OFFS=4

;;

*)

  echo "Please implement other architecture here"

  exit_untested

esac



: "Test get argument (1)"

echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string" > kprobe_events

echo 1 > events/kprobes/testprobe/enable

! echo test >> kprobe_events

tail -n 1 trace | grep -qe "testprobe.* arg1=\"test\""



echo 0 > events/kprobes/testprobe/enable

: "Test get argument (2)"

echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string arg2=+0(+${OFFS}(${ARG2})):string" > kprobe_events

echo 1 > events/kprobes/testprobe/enable

! echo test1 test2 >> kprobe_events

tail -n 1 trace | grep -qe "testprobe.* arg1=\"test1\" arg2=\"test2\""



echo 0 > events/enable

echo > kprobe_events

tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_syntax.tc

0 → 100644
+97 −0
Original line number Diff line number Diff line 
#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Kprobe event argument syntax



[ -f kprobe_events ] || exit_unsupported # this is configurable



grep "x8/16/32/64" README > /dev/null || exit_unsupported # version issue



echo 0 > events/enable

echo > kprobe_events



PROBEFUNC="vfs_read"

GOODREG=

BADREG=

GOODSYM="_sdata"

if ! grep -qw ${GOODSYM} /proc/kallsyms ; then

  GOODSYM=$PROBEFUNC

fi

BADSYM="deaqswdefr"

SYMADDR=0x`grep -w ${GOODSYM} /proc/kallsyms | cut -f 1 -d " "`

GOODTYPE="x16"

BADTYPE="y16"



case `uname -m` in

x86_64|i[3456]86)

  GOODREG=%ax

  BADREG=%ex

;;

aarch64)

  GOODREG=%x0

  BADREG=%ax

;;

arm*)

  GOODREG=%r0

  BADREG=%ax

;;

esac



test_goodarg() # Good-args

{

  while [ "$1" ]; do

    echo "p ${PROBEFUNC} $1" > kprobe_events

    shift 1

  done;

}



test_badarg() # Bad-args

{

  while [ "$1" ]; do

    ! echo "p ${PROBEFUNC} $1" > kprobe_events

    shift 1

  done;

}



echo > kprobe_events



: "Register access"

test_goodarg ${GOODREG}

test_badarg ${BADREG}



: "Symbol access"

test_goodarg "@${GOODSYM}" "@${SYMADDR}" "@${GOODSYM}+10" "@${GOODSYM}-10"

test_badarg "@" "@${BADSYM}" "@${GOODSYM}*10" "@${GOODSYM}/10" \

	    "@${GOODSYM}%10" "@${GOODSYM}&10" "@${GOODSYM}|10"



: "Stack access"

test_goodarg "\$stack" "\$stack0" "\$stack1"

test_badarg "\$stackp" "\$stack0+10" "\$stack1-10"



: "Retval access"

echo "r ${PROBEFUNC} \$retval" > kprobe_events

! echo "p ${PROBEFUNC} \$retval" > kprobe_events



: "Comm access"

test_goodarg "\$comm"



: "Indirect memory access"

test_goodarg "+0(${GOODREG})" "-0(${GOODREG})" "+10(\$stack)" \

	"+0(\$stack1)" "+10(@${GOODSYM}-10)" "+0(+10(+20(\$stack)))"

test_badarg "+(${GOODREG})" "(${GOODREG}+10)" "-(${GOODREG})" "(${GOODREG})" \

	"+10(\$comm)" "+0(${GOODREG})+10"



: "Name assignment"

test_goodarg "varname=${GOODREG}"

test_badarg "varname=varname2=${GOODREG}"



: "Type syntax"

test_goodarg "${GOODREG}:${GOODTYPE}"

test_badarg "${GOODREG}::${GOODTYPE}" "${GOODREG}:${BADTYPE}" \

	"${GOODTYPE}:${GOODREG}"



: "Combination check"



test_goodarg "\$comm:string" "+0(\$stack):string"

test_badarg "\$comm:x64" "\$stack:string" "${GOODREG}:string"



echo > kprobe_events

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