Re: [PATCH] [RFC V1]s390/perf: fix 'start' address of module's map

From: Songshan Gong
Date: Wed Jul 13 2016 - 02:40:16 EST

å 7/11/2016 8:01 PM, Jiri Olsa åé:
On Mon, Jul 11, 2016 at 07:06:14PM +0800, Songshan Gong wrote:


we have following functions in tools/lib/api/fs to read
single number from file, which I assume you do above:

int sysfs__read_int(const char *entry, int *value);
int sysfs__read_ull(const char *entry, unsigned long long *value);

please check if you could use some of them,
we could add some more generic one if needed

It seems infeasible.
Each value in /sys/module/[module name]/sections/.text is a string like
But the core function 'strtoull(line, NULL, 10)' in sysfs__read_ull is based
on decimal.

Maybe you can introduce a new argument indicating the value is based on hex
or decimal, or binary?

yea we could specify it directly and add something like:

int filename__read_ull(const char *filename, unsigned long long *value, int base)

plus some other higher layer helpers..

but I wonder if we could use the base 0 (like in the attached patch),
the man page says it should be able to detect the base

we'd need to check all the current usage to make sure nothing gets broken


Since your patch havn't pushed to devel branch, my next version patch will still use the origin method to parse value from /sys/.


diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
index 08556cf2c70d..d18ae548468a 100644
--- a/tools/lib/api/fs/fs.c
+++ b/tools/lib/api/fs/fs.c
@@ -292,7 +292,7 @@ int filename__read_ull(const char *filename, unsigned long long *value)
return -1;

if (read(fd, line, sizeof(line)) > 0) {
- *value = strtoull(line, NULL, 10);
+ *value = strtoull(line, NULL, 0);
if (*value != ULLONG_MAX)
err = 0;

SongShan Gong