Re: [PATCH 1/4] perf record: Provide detailed information on s390 CPU

[Arnaldo Carvalho de Melo]

Em Fri, Feb 16, 2018 at 01:55:43PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Feb 13, 2018 at 04:14:16PM +0100, Thomas Richter escreveu:
> 
> 
>   49    38.13 ubuntu:16.04-x-s390           : FAIL s390x-linux-gnu-gcc 
> (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609
> 
> 
> Humm, this seems to be the one causing this:
> 
>   LINK     /tmp/build/perf/plugin_hrtimer.so
>   LINK     /tmp/build/perf/plugin_kmem.so
> In file included from /usr/s390x-linux-gnu/include/string.h:635:0,
>                  from arch/s390/util/header.c:16:
> In function 'strncat',
>     inlined from 'get_cpuid' at arch/s390/util/header.c:65:5:
> /usr/s390x-linux-gnu/include/bits/string3.h:156:10: error: call to 
> __builtin___strncat_chk might overflow destination buffer [-Werror]
>    return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));

Ok, now I can build it:

[acme@seventh perf]$ file ../tmp/perf
../tmp/perf: ELF 64-bit MSB shared object, IBM S/390, version 1 (SYSV), 
dynamically linked, interpreter /lib/ld64.so.1, for GNU/Linux 3.2.0, 
BuildID[sha1]=82a8ff9eb04082acd1630a0f4ff3816d68982eb7, with debug_info, not 
stripped
[acme@seventh perf]$

With the following patch, using scnprintf (snprintf also has issues),
please try applying this on top of yours and checking that the end
result is sane.

- Arnaldo

diff --git a/tools/perf/arch/s390/util/header.c 
b/tools/perf/arch/s390/util/header.c
index 3d29ba47edce..a78064c25ced 100644
--- a/tools/perf/arch/s390/util/header.c
+++ b/tools/perf/arch/s390/util/header.c
@@ -32,6 +32,7 @@ int get_cpuid(char *buffer, size_t sz)
 {
        char *cp, *line = NULL, *line2;
        char type[8], model[33], version[8], manufacturer[32], authorization[8];
+       int tpsize = 0, mdsize = 0, vssize = 0, mfsize = 0, atsize = 0;
        int read;
        unsigned long line_sz;
        size_t nbytes;
@@ -61,25 +62,27 @@ int get_cpuid(char *buffer, size_t sz)
                if (!strncmp(line, SYSINFO_MANU, strlen(SYSINFO_MANU))) {
                        line2 = line + strlen(SYSINFO_MANU);
 
-                       while ((cp = strtok_r(line2, "\n ", &line2)))
-                               strncat(manufacturer, cp, sizeof(manufacturer));
+                       while ((cp = strtok_r(line2, "\n ", &line2))) {
+                               mfsize += scnprintf(manufacturer + mfsize,
+                                                   sizeof(manufacturer) - 
mfsize, "%s", cp);
+                       }
                }
 
                if (!strncmp(line, SYSINFO_TYPE, strlen(SYSINFO_TYPE))) {
                        line2 = line + strlen(SYSINFO_TYPE);
 
-                       while ((cp = strtok_r(line2, "\n ", &line2)))
-                               strncat(type, cp, sizeof(type));
+                       while ((cp = strtok_r(line2, "\n ", &line2))) {
+                               tpsize += scnprintf(type + tpsize,
+                                                   sizeof(type) - tpsize, 
"%s", cp);
+                       }
                }
 
                if (!strncmp(line, SYSINFO_MODEL, strlen(SYSINFO_MODEL))) {
                        line2 = line + strlen(SYSINFO_MODEL);
 
                        while ((cp = strtok_r(line2, "\n ", &line2))) {
-                               if (model[0])
-                                       strcat(model, ",");
-                               if (strlen(model) + strlen(cp) < sizeof(model))
-                                       strncat(model, cp, strlen(cp));
+                               mdsize += scnprintf(model + mdsize, 
sizeof(type) - mdsize,
+                                                   "%s%s", model[0] ? "," : 
"", cp);
                        }
                        break;
                }
@@ -108,14 +111,15 @@ int get_cpuid(char *buffer, size_t sz)
                                     strlen(SRVLVL_VERSION))) {
                                char *sep = strchr(cp, '=');
 
-                               strncat(version, sep + 1, sizeof(version));
+                               vssize += scnprintf(version + vssize,
+                                                   sizeof(version) - vssize, 
"%s", sep + 1);
                        }
                        if (!strncmp(cp, SRVLVL_AUTHORIZATION,
                                     strlen(SRVLVL_AUTHORIZATION))) {
                                char *sep = strchr(cp, '=');
 
-                               strncat(authorization, sep + 1,
-                                       sizeof(authorization));
+                               atsize += scnprintf(authorization + atsize,
+                                                   sizeof(authorization) - 
atsize, "%s", sep + 1);
                        }
                }
        }