Hi Rik, On Wed, Oct 11, 2023 at 12:53:30PM -0400, Rik van Riel wrote: > Sigh, once again I did a git commit --amend without the latest file change being > included. The change below should be good. Working with both git and hg gets me sometimes :/ > ---8<--- > > The execve syscall returns -E2BIG in 3 cases: > - The total length of the command line arguments and environment is too large. > - An argument or environment string is longer than MAX_ARG_STRLEN. I'm still concerned by the wording of this sentence (and the next one). When I (and any user-space programmer, I think) read "string is longer than FOO", I read `strlen(string) > FOO`. Since it's rather `strlen(string) >= FOO`, I think you should clarify. How about this? - An argument or environment string is longer (including the null byte) than MAX_ARG_STRLEN. Thanks, Alex > - The full path to the executable exceeds MAX_ARG_STRLEN. > > Spell out all 3 cases in the -E2BIG section. > > Discovered by moving a too large commandline parameter to an environment > variable, and finding that things still did not work. Examined the code > in fs/exec.c to get the details. > > This simple shell script starts failing at 2^17 on a system with 4kB > page size: > ./exec2big.sh: line 10: /bin/true: Argument list too long > fork failed at loop 17 > > STRING="a" > > for loop in `seq 20`; do > STRING="$STRING$STRING" > export STRING > if /bin/true ; then > : # still under the limit > else > echo "fork failed at loop $loop" > fi > done Thank you very much! > > Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx> > Suggested-by: Matthew House <mattlloydhouse@xxxxxxxxx> > --- > man2/execve.2 | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/man2/execve.2 b/man2/execve.2 > index 0d9582492ad1..b689101771e5 100644 > --- a/man2/execve.2 > +++ b/man2/execve.2 > @@ -449,7 +449,12 @@ The total number of bytes in the environment > .RI ( envp ) > and argument list > .RI ( argv ) > -is too large. > +is too large, > +an argument or environment string is too long, > +or the full > +.I pathname > +of the executable is too long. > +The terminating NUL is counted as part of the string length. > .TP > .B EACCES > Search permission is denied on a component of the path prefix of > -- > 2.41.0 > > -- <https://www.alejandro-colomar.es/>
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