2021-02-23 16:04:40

by Andrew Scull

Subject: [PATCH v2 2/4] bug: Factor out a getter for a bug's file line

There is some non-trivial config-based logic to get the file name and
line number associated with a bug. Factor this out to a getter that can
be resused.

Signed-off-by: Andrew Scull <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Steven Rostedt (VMware)" <[email protected]>
---
include/linux/bug.h | 3 +++
lib/bug.c | 27 +++++++++++++++++----------
2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index f639bd0122f3..e3841bee4c8d 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -36,6 +36,9 @@ static inline int is_warning_bug(const struct bug_entry *bug)
return bug->flags & BUGFLAG_WARNING;
}

+void bug_get_file_line(struct bug_entry *bug, const char **file,
+ unsigned int *line);
+
struct bug_entry *find_bug(unsigned long bugaddr);

enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
diff --git a/lib/bug.c b/lib/bug.c
index 4ab398a2de93..f936615176b8 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -130,6 +130,22 @@ static inline struct bug_entry *module_find_bug(unsigned long bugaddr)
}
#endif

+void bug_get_file_line(struct bug_entry *bug, const char **file,
+ unsigned int *line)
+{
+ *file = NULL;
+ *line = 0;
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
+ *file = bug->file;
+#else
+ *file = (const char *)bug + bug->file_disp;
+#endif
+ *line = bug->line;
+#endif
+}
+
struct bug_entry *find_bug(unsigned long bugaddr)
{
struct bug_entry *bug;
@@ -156,17 +172,8 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)

disable_trace_on_warning();

- file = NULL;
- line = 0;
+ bug_get_file_line(bug, &file, &line);

-#ifdef CONFIG_DEBUG_BUGVERBOSE
-#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
- file = bug->file;
-#else
- file = (const char *)bug + bug->file_disp;
-#endif
- line = bug->line;
-#endif
warning = (bug->flags & BUGFLAG_WARNING) != 0;
once = (bug->flags & BUGFLAG_ONCE) != 0;
done = (bug->flags & BUGFLAG_DONE) != 0;
--
2.30.0.617.g56c4b15f3c-goog

2021-02-23 16:39:26

by Steven Rostedt

Subject: Re: [PATCH v2 2/4] bug: Factor out a getter for a bug's file line

On Tue, 23 Feb 2021 15:57:57 +0000
Andrew Scull <[email protected]> wrote:

> There is some non-trivial config-based logic to get the file name and
> line number associated with a bug. Factor this out to a getter that can
> be resused.
>
> Signed-off-by: Andrew Scull <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: "Steven Rostedt (VMware)" <[email protected]>
> ---
> include/linux/bug.h | 3 +++
> lib/bug.c | 27 +++++++++++++++++----------
> 2 files changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/bug.h b/include/linux/bug.h
> index f639bd0122f3..e3841bee4c8d 100644
> --- a/include/linux/bug.h
> +++ b/include/linux/bug.h
> @@ -36,6 +36,9 @@ static inline int is_warning_bug(const struct bug_entry *bug)
> return bug->flags & BUGFLAG_WARNING;
> }
>
> +void bug_get_file_line(struct bug_entry *bug, const char **file,
> + unsigned int *line);
> +
> struct bug_entry *find_bug(unsigned long bugaddr);
>
> enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
> diff --git a/lib/bug.c b/lib/bug.c
> index 4ab398a2de93..f936615176b8 100644
> --- a/lib/bug.c
> +++ b/lib/bug.c
> @@ -130,6 +130,22 @@ static inline struct bug_entry *module_find_bug(unsigned long bugaddr)
> }
> #endif
>
> +void bug_get_file_line(struct bug_entry *bug, const char **file,
> + unsigned int *line)
> +{
> + *file = NULL;
> + *line = 0;
> +
> +#ifdef CONFIG_DEBUG_BUGVERBOSE
> +#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
> + *file = bug->file;
> +#else
> + *file = (const char *)bug + bug->file_disp;
> +#endif
> + *line = bug->line;

Not that it should be part of this patch, as this patch is moving the code
and shouldn't modify it, but as a micro optimization, we could remove the
initialization from the beginning and place it here:

#else
*file = NULL;
*line = 0;

But again, this patch is fine.

Reviewed-by: Steven Rostedt (VMware) <[email protected]>

-- Steve


> +#endif
> +}
> +
> struct bug_entry *find_bug(unsigned long bugaddr)
> {
> struct bug_entry *bug;
> @@ -156,17 +172,8 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
>
> disable_trace_on_warning();
>
> - file = NULL;
> - line = 0;
> + bug_get_file_line(bug, &file, &line);
>
> -#ifdef CONFIG_DEBUG_BUGVERBOSE
> -#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
> - file = bug->file;
> -#else
> - file = (const char *)bug + bug->file_disp;
> -#endif
> - line = bug->line;
> -#endif
> warning = (bug->flags & BUGFLAG_WARNING) != 0;
> once = (bug->flags & BUGFLAG_ONCE) != 0;
> done = (bug->flags & BUGFLAG_DONE) != 0;