Em Wed, Jan 24, 2018 at 02:54:11PM -0600, Josh Poimboeuf escreveu:
> On Tue, Jan 23, 2018 at 07:38:37PM -0500, Arvind Sankar wrote:
> > We inherited this hack with the original code from the Git project. The
> > select call is invalid as the two fd_set pointers should not be aliased.
> >
> > We could fix it, but the Git project removed this hack in 2012 in commit
> > e8320f3 (pager: drop "wait for output to run less" hack). The bug it
> > worked around was apparently fixed in less back in June 2007.
> >
> > So remove the hack from here as well.
> >
> > Signed-off-by: Arvind Sankar <nived...@alum.mit.edu>
>
> Looks good to me.
>
> Acked-by: Josh Poimboeuf <jpoim...@redhat.com>
>
> Libsubcmd is used by perf and objtool, so adding the perf maintainers to
> CC. Arnaldo, do you want to pick this one up?
Sure, I'll put it in my perf/core branch.
- Arnaldo
> > ---
> > tools/lib/subcmd/pager.c | 17 -----------------
> > tools/lib/subcmd/run-command.c | 2 --
> > tools/lib/subcmd/run-command.h | 1 -
> > 3 files changed, 20 deletions(-)
> >
> > diff --git a/tools/lib/subcmd/pager.c b/tools/lib/subcmd/pager.c
> > index 5ba754d17952..94d61d9b511f 100644
> > --- a/tools/lib/subcmd/pager.c
> > +++ b/tools/lib/subcmd/pager.c
> > @@ -1,5 +1,4 @@
> > // SPDX-License-Identifier: GPL-2.0
> > -#include <sys/select.h>
> > #include <stdlib.h>
> > #include <stdio.h>
> > #include <string.h>
> > @@ -23,21 +22,6 @@ void pager_init(const char *pager_env)
> > subcmd_config.pager_env = pager_env;
> > }
> >
> > -static void pager_preexec(void)
> > -{
> > - /*
> > - * Work around bug in "less" by not starting it until we
> > - * have real input
> > - */
> > - fd_set in;
> > -
> > - FD_ZERO(&in);
> > - FD_SET(0, &in);
> > - select(1, &in, NULL, &in, NULL);
> > -
> > - setenv("LESS", "FRSX", 0);
> > -}
> > -
> > static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
> > static struct child_process pager_process;
> >
> > @@ -84,7 +68,6 @@ void setup_pager(void)
> > pager_argv[2] = pager;
> > pager_process.argv = pager_argv;
> > pager_process.in = -1;
> > - pager_process.preexec_cb = pager_preexec;
> >
> > if (start_command(&pager_process))
> > return;
> > diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c
> > index 5cdac2162532..9e9dca717ed7 100644
> > --- a/tools/lib/subcmd/run-command.c
> > +++ b/tools/lib/subcmd/run-command.c
> > @@ -120,8 +120,6 @@ int start_command(struct child_process *cmd)
> > unsetenv(*cmd->env);
> > }
> > }
> > - if (cmd->preexec_cb)
> > - cmd->preexec_cb();
> > if (cmd->exec_cmd) {
> > execv_cmd(cmd->argv);
> > } else {
> > diff --git a/tools/lib/subcmd/run-command.h b/tools/lib/subcmd/run-command.h
> > index 17d969c6add3..6256268802b5 100644
> > --- a/tools/lib/subcmd/run-command.h
> > +++ b/tools/lib/subcmd/run-command.h
> > @@ -46,7 +46,6 @@ struct child_process {
> > unsigned no_stderr:1;
> > unsigned exec_cmd:1; /* if this is to be external sub-command */
> > unsigned stdout_to_stderr:1;
> > - void (*preexec_cb)(void);
> > };
> >
> > int start_command(struct child_process *);
> > --
> > 2.13.6
> >
>
> --
> Josh
