Re: [dmidecode] [patch #8989] Output "Invalid entry length.. Fixed up" warning to stderr

[Jean Delvare]

Hi Kevin,

On Thu, 28 Apr 2016 18:56:26 -0700, Kevin Bowling wrote:
> dmidecode 3.0 breaks DMI values of some tools like SaltStack that read
> stdout for specific values to populate data structures about a host on some
> hardware because of a warning like "Invalid entry length (16). Fixed up to
> 11."
> 
> My proposed fix is to simply move it to stderr
> http://savannah.nongnu.org/patch/?8989

I've generalized it after seeing another related bug report. Can you
try the following patch?

From: Jean Delvare <address@hidden>
Subject: dmidecode: Move error messages to stderr

Consistently write error messages to stderr, to avoid messing up the
output of "dmidecode -s". Based on preliminary patches by
Kevin Bowling and Simon Rettberg.

Fixes bug #47274:
https://savannah.nongnu.org/bugs/?47274
Fixes bug #48158:
https://savannah.nongnu.org/bugs/?48158
Supersedes patch #8989:
https://savannah.nongnu.org/patch/?8989
---
 dmidecode.c |   37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

--- dmidecode.orig/dmidecode.c  2016-07-04 11:36:36.961481311 +0200
+++ dmidecode/dmidecode.c       2016-07-04 12:06:51.529344282 +0200
@@ -2958,7 +2958,8 @@ static void dmi_fixup_type_34(struct dmi
         && is_printable(p + 0x0B, 0x10 - 0x0B))
        {
                if (!(opt.flags & FLAG_QUIET) && display)
-                       printf("Invalid entry length (%u). Fixed up to %u.\n",
+                       fprintf(stderr,
+                               "Invalid entry length (%u). Fixed up to %u.\n",
                                0x10, 0x0B);
                h->length = 0x0B;
        }
@@ -4427,9 +4428,14 @@ static void dmi_table_decode(u8 *buf, u3
                 */
                if (h.length < 4)
                {
-                       printf("Invalid entry length (%u). DMI table is "
-                              "broken! Stop.\n\n", (unsigned int)h.length);
-                       opt.flags |= FLAG_QUIET;
+                       if (!(opt.flags & FLAG_QUIET))
+                       {
+                               fprintf(stderr,
+                                       "Invalid entry length (%u). DMI table "
+                                       "is broken! Stop.\n\n",
+                                       (unsigned int)h.length);
+                               opt.flags |= FLAG_QUIET;
+                       }
                        break;
                }
 
@@ -4490,11 +4496,11 @@ static void dmi_table_decode(u8 *buf, u3
        if (!(opt.flags & FLAG_QUIET))
        {
                if (num && i != num)
-                       printf("Wrong DMI structures count: %d announced, "
+                       fprintf(stderr, "Wrong DMI structures count: %d 
announced, "
                                "only %d decoded.\n", num, i);
                if ((unsigned long)(data - buf) > len
                 || (num && (unsigned long)(data - buf) < len))
-                       printf("Wrong DMI structures length: %u bytes "
+                       fprintf(stderr, "Wrong DMI structures length: %u bytes "
                                "announced, structures occupy %lu bytes.\n",
                                len, (unsigned long)(data - buf));
        }
@@ -4539,7 +4545,7 @@ static void dmi_table(off_t base, u32 le
                buf = read_file(&size, devmem);
                if (!(opt.flags & FLAG_QUIET) && num && size != (size_t)len)
                {
-                       printf("Wrong DMI structures length: %u bytes "
+                       fprintf(stderr, "Wrong DMI structures length: %u bytes "
                                "announced, only %lu bytes available.\n",
                                len, (unsigned long)size);
                }
@@ -4652,14 +4658,16 @@ static int smbios_decode(u8 *buf, const
                case 0x021F:
                case 0x0221:
                        if (!(opt.flags & FLAG_QUIET))
-                               printf("SMBIOS version fixup (2.%d -> 2.%d).\n",
-                                      ver & 0xFF, 3);
+                               fprintf(stderr,
+                                       "SMBIOS version fixup (2.%d -> 
2.%d).\n",
+                                       ver & 0xFF, 3);
                        ver = 0x0203;
                        break;
                case 0x0233:
                        if (!(opt.flags & FLAG_QUIET))
-                               printf("SMBIOS version fixup (2.%d -> 2.%d).\n",
-                                      51, 6);
+                               fprintf(stderr,
+                                       "SMBIOS version fixup (2.%d -> 
2.%d).\n",
+                                       51, 6);
                        ver = 0x0206;
                        break;
        }
@@ -4771,6 +4779,13 @@ int main(int argc, char * const argv[])
        int efi;
        u8 *buf;
 
+       /*
+        * We don't want stdout and stderr to be mixed up if both are
+        * redirected to the same file.
+        */
+       setlinebuf(stdout);
+       setlinebuf(stderr);
+
        if (sizeof(u8) != 1 || sizeof(u16) != 2 || sizeof(u32) != 4 || '\0' != 
0)
        {
                fprintf(stderr, "%s: compiler incompatibility\n", argv[0]);


-- 
Jean Delvare
SUSE L3 Support