The commit 9aaf5a5("perf probe: Check kprobes blacklist
when adding new events"), perf probe supports checking
the blacklist of the fuctions which can not be probed.
But the checking condition is wrong, that the end_addr
of the symbol which is the start_addr of the next symbol
can't be included.
Signed-off-by: Li Bin <[email protected]>
---
tools/perf/util/probe-event.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index a2670e9..bf7c928 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2373,7 +2373,7 @@ static int kprobe_blacklist__load(struct list_head *blacklist)
struct kprobe_blacklist_node *node;
list_for_each_entry(node, blacklist, list) {
- if (node->start <= address && address <= node->end)
+ if (node->start <= address && address < node->end)
return node;
}
--
1.7.12.4
Em Tue, Aug 29, 2017 at 08:57:23PM +0800, Li Bin escreveu:
> The commit 9aaf5a5("perf probe: Check kprobes blacklist
> when adding new events"), perf probe supports checking
> the blacklist of the fuctions which can not be probed.
> But the checking condition is wrong, that the end_addr
> of the symbol which is the start_addr of the next symbol
> can't be included.
Applied, with the following committer notes added:
Committer notes:
IOW make it match its kernel counterpart in kernel/kprobes.c:
bool within_kprobe_blacklist(unsigned long addr)
Each entry have as its end address not its end address, but the first
address _outside_ that symbol, which for related functions, is the first
address of the next symbol, like these from kernel/trace/trace_probe.c:
0xffffffffbd198df0-0xffffffffbd198e40 print_type_u8
0xffffffffbd198e40-0xffffffffbd198e90 print_type_u16
0xffffffffbd198e90-0xffffffffbd198ee0 print_type_u32
0xffffffffbd198ee0-0xffffffffbd198f30 print_type_u64
0xffffffffbd198f30-0xffffffffbd198f80 print_type_s8
0xffffffffbd198f80-0xffffffffbd198fd0 print_type_s16
0xffffffffbd198fd0-0xffffffffbd199020 print_type_s32
0xffffffffbd199020-0xffffffffbd199070 print_type_s64
0xffffffffbd199070-0xffffffffbd1990c0 print_type_x8
0xffffffffbd1990c0-0xffffffffbd199110 print_type_x16
0xffffffffbd199110-0xffffffffbd199160 print_type_x32
0xffffffffbd199160-0xffffffffbd1991b0 print_type_x64
But not always:
0xffffffffbd1997b0-0xffffffffbd1997c0 fetch_kernel_stack_address (kernel/trace/trace_probe.c)
0xffffffffbd1c57f0-0xffffffffbd1c58b0 __context_tracking_enter (kernel/context_tracking.c)
Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events")
Commit-ID: 2c29461e273abaf149cf8220c3403e9d67dd8b61
Gitweb: http://git.kernel.org/tip/2c29461e273abaf149cf8220c3403e9d67dd8b61
Author: Li Bin <[email protected]>
AuthorDate: Tue, 29 Aug 2017 20:57:23 +0800
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 29 Aug 2017 11:14:12 -0300
perf probe: Fix kprobe blacklist checking condition
The commit 9aaf5a5f479b ("perf probe: Check kprobes blacklist when
adding new events"), 'perf probe' supports checking the blacklist of the
fuctions which can not be probed. But the checking condition is wrong,
that the end_addr of the symbol which is the start_addr of the next
symbol can't be included.
Committer notes:
IOW make it match its kernel counterpart in kernel/kprobes.c:
bool within_kprobe_blacklist(unsigned long addr)
Each entry have as its end address not its end address, but the first
address _outside_ that symbol, which for related functions, is the first
address of the next symbol, like these from kernel/trace/trace_probe.c:
0xffffffffbd198df0-0xffffffffbd198e40 print_type_u8
0xffffffffbd198e40-0xffffffffbd198e90 print_type_u16
0xffffffffbd198e90-0xffffffffbd198ee0 print_type_u32
0xffffffffbd198ee0-0xffffffffbd198f30 print_type_u64
0xffffffffbd198f30-0xffffffffbd198f80 print_type_s8
0xffffffffbd198f80-0xffffffffbd198fd0 print_type_s16
0xffffffffbd198fd0-0xffffffffbd199020 print_type_s32
0xffffffffbd199020-0xffffffffbd199070 print_type_s64
0xffffffffbd199070-0xffffffffbd1990c0 print_type_x8
0xffffffffbd1990c0-0xffffffffbd199110 print_type_x16
0xffffffffbd199110-0xffffffffbd199160 print_type_x32
0xffffffffbd199160-0xffffffffbd1991b0 print_type_x64
But not always:
0xffffffffbd1997b0-0xffffffffbd1997c0 fetch_kernel_stack_address (kernel/trace/trace_probe.c)
0xffffffffbd1c57f0-0xffffffffbd1c58b0 __context_tracking_enter (kernel/context_tracking.c)
Signed-off-by: Li Bin <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Cc: [email protected]
Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/probe-event.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index d7cd114..b7aaf9b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2395,7 +2395,7 @@ kprobe_blacklist__find_by_address(struct list_head *blacklist,
struct kprobe_blacklist_node *node;
list_for_each_entry(node, blacklist, list) {
- if (node->start <= address && address <= node->end)
+ if (node->start <= address && address < node->end)
return node;
}
On Tue, 29 Aug 2017 20:57:23 +0800
Li Bin <[email protected]> wrote:
> The commit 9aaf5a5("perf probe: Check kprobes blacklist
> when adding new events"), perf probe supports checking
> the blacklist of the fuctions which can not be probed.
> But the checking condition is wrong, that the end_addr
> of the symbol which is the start_addr of the next symbol
> can't be included.
Oops, right.
Acked-by: Masami Hiramatsu <[email protected]>
Thanks!
BTW, should we use memory_contains() macro for this check too...
>
> Signed-off-by: Li Bin <[email protected]>
> ---
> tools/perf/util/probe-event.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index a2670e9..bf7c928 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2373,7 +2373,7 @@ static int kprobe_blacklist__load(struct list_head *blacklist)
> struct kprobe_blacklist_node *node;
>
> list_for_each_entry(node, blacklist, list) {
> - if (node->start <= address && address <= node->end)
> + if (node->start <= address && address < node->end)
> return node;
> }
>
> --
> 1.7.12.4
>
--
Masami Hiramatsu <[email protected]>