[LU-9830] string truncation from snprintf in libcfs/util/parser.c::Parser_list_commands()

• Type: Bug
• Resolution: Duplicate
• Priority: Minor
• Severity: 3
• Assignee: WC Triage
• Reporter: Oleg Drokin

Description

Modern gcc warns that:

util/parser.c: In function Б─≤Parser_list_commandsБ─≥:
util/parser.c:575:25: error: Б─≤%2dБ─≥ directive output may be truncated writing between 2 and 10 bytes into a region of size 4 [-Werror=format-truncation=]
    snprintf(fmt, 6, "%%-%2ds", char_max - len);
                         ^~~
util/parser.c:575:21: note: directive argument in the range [1, 2147483647]
    snprintf(fmt, 6, "%%-%2ds", char_max - len);
                     ^~~~~~~~~
util/parser.c:575:4: note: Б─≤snprintfБ─≥ output between 6 and 14 bytes into a destination of size 6
    snprintf(fmt, 6, "%%-%2ds", char_max - len);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[4]: *** [autoMakefile:669: libcfsutil_a-parser.o] Error 1
make[4]: Leaving directory '/home/green/smt/git/lustre-release/libcfs/libcfs'

there's some funky business going on with presumed column width so I guess we cannot just increase 6 to 14?

Issue Links

• is related to: LU-16392 Bash completion regressions, lctl and lfs
• is related to: LU-6142 Enforce Linux kernel coding style in all code

Comments

[Peter Jones]

Fixed under LU-16392

[Andreas Dilger]

Fixed in commit v2_15_53-135-gb4cc570ad11c

[Andreas Dilger]

The command truncation was fixed by patch https://review.whamcloud.com/49484 "LU-16392 utils: use --list-commands for bash completion".

[James A Simmons]

Is this resolved ?

[Andreas Dilger]

The compiler problems were fixed with patch https://review.whamcloud.com/35384 "LU-6142 util: Fix style issues for parser.c", but there are still a couple of commands truncated by one character - "changelog_deregister" and "lustre_build_version". The latter could likely be removed - it was superseded in v2_6_50_0-16-g593b6ab6d219 with "lctl get_param version" and "--version", but "changelog_deregister" can't.

It would probably make sense to add a check to prevent new commands > 19 characters in length from being added.