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From: Vladimir Mezentsev <>
Subject: Fwd: Werror=format-security issue from gprofng/src/
Date: Fri, 10 Jun 2022 10:20:50 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

  This is 28968 <> 
- gprofng doesn't build with -Werror=format-security

I'm working on it. I'll fix it by Monday/Tuesday.


> Vladimir, can you look at this?
> -------- Forwarded Message --------
> Subject: 	Werror=format-security issue from gprofng/src/
> Date: 	Tue, 7 Jun 2022 10:49:50 -0400
> From: 	Yichao Yu via Gdb<>
> Reply-To: 	Yichao Yu<>
> To:
> I got a format-security werror on gprofng/src/ when trying to
> build the master version of gdb (the compiler flag is added by the
> archlinuxcn build machine).
> While I could disable the flag, I think there might be a real issue
> looking at the code.
> The line that causes the issue is
> which uses a "dynamic" format string without any argument. AFAICT, the
> fmt3 is only ever initialized in
> `er_print_experiment::overview_summary` and if I read it correctly,
> it's initialized to a string with no actual formatting inputs other
> than a `%%`. It is used, however, twice in
> `er_print_experiment::overview_value`, one given two zeros as the
> arguments and one given no arguments so it looks a bit suspicious.
> The git log shows now history of this file so I'm not sure what's the
> intention but my best guess is
> 1. the `fprintf (out_file, fmt3, 0., 0.);` was meant to be using
> `fmt4`. (I assume this is to avoid nan from total_value = 0), or
> 2. since fmt3 is actually a string that's more or less "0.0 (0.0)"
> with padding, the two `0.`s passed to fmt3 are probably bogus and it
> should be the same as the `fprintf (out_file, fmt3);` below
> if my understanding is correct, I think in either case one can simply
> avoid using fmt3 with fprintf by just removing the extra % from it and
> directly write it to the output instead. (i.e.
> Did I miss anything?
> Yichao

  parent reply	other threads:[~2022-06-10 17:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-07 14:49 Yichao Yu
     [not found] ` <>
2022-06-10 17:20   ` Vladimir Mezentsev [this message]
2022-06-12 22:29     ` Yichao Yu

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