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[libiberty patch] Fix PGO bootstrap

Browse source 
https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01386.html
	PR driver/87056
	* pex-unix.c (pex_unix_exec_child): Duplicate bad_fn into local
	scopes to avoid potential clobber.

Co-Authored-By: Martin Liska <mliska@suse.cz>

From-SVN: r263807
This commit is contained in:
Nathan Sidwell 2018-08-23 10:21:21 +00:00 • committed by Nathan Sidwell
parent ebdb6f2377
commit 832c74d935
2 changed files with 89 additions and 79 deletions
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7
libiberty/ChangeLog
View file

@ -1,3 +1,10 @@
2018-08-23 Nathan Sidwell <nathan@acm.org>
Martin Liska <mliska@suse.cz>
PR driver/87056
* pex-unix.c (pex_unix_exec_child): Duplicate bad_fn into local
scopes to avoid potential clobber.
2018-08-20 Nathan Sidwell <nathan@acm.org>
* pex-unix.c (pex_child_error): Delete.

161
libiberty/pex-unix.c
View file

@ -582,8 +582,6 @@ pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
issues. */
char **save_environ = environ;
const char *bad_fn = NULL;
for (retries = 0; retries < 4; ++retries)
{
pid = vfork ();
@ -602,62 +600,64 @@ pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
case 0:
/* Child process. */
if (!bad_fn && in != STDIN_FILE_NO)
{
if (dup2 (in, STDIN_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (in) < 0)
bad_fn = "close";
}
if (!bad_fn && out != STDOUT_FILE_NO)
{
if (dup2 (out, STDOUT_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (out) < 0)
bad_fn = "close";
}
if (!bad_fn && errdes != STDERR_FILE_NO)
{
if (dup2 (errdes, STDERR_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (errdes) < 0)
bad_fn = "close";
}
if (!bad_fn && toclose >= 0)
{
if (close (toclose) < 0)
bad_fn = "close";
}
if (!bad_fn && (flags & PEX_STDERR_TO_STDOUT) != 0)
{
if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0)
bad_fn = "dup2";
}
if (!bad_fn)
{
if (env)
/* NOTE: In a standard vfork implementation this clobbers
the parent's copy of environ "too" (in reality there's
only one copy). This is ok as we restore it below. */
environ = (char**) env;
if ((flags & PEX_SEARCH) != 0)
{
execvp (executable, to_ptr32 (argv));
bad_fn = "execvp";
}
else
{
execv (executable, to_ptr32 (argv));
bad_fn = "execv";
}
}
/* Something failed, report an error. We don't use stdio
routines, because we might be here due to a vfork call. */
{
ssize_t retval = 0;
int err = errno;
const char *bad_fn = NULL;
if (!bad_fn && in != STDIN_FILE_NO)
{
if (dup2 (in, STDIN_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (in) < 0)
bad_fn = "close";
}
if (!bad_fn && out != STDOUT_FILE_NO)
{
if (dup2 (out, STDOUT_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (out) < 0)
bad_fn = "close";
}
if (!bad_fn && errdes != STDERR_FILE_NO)
{
if (dup2 (errdes, STDERR_FILE_NO) < 0)
bad_fn = "dup2";
else if (close (errdes) < 0)
bad_fn = "close";
}
if (!bad_fn && toclose >= 0)
{
if (close (toclose) < 0)
bad_fn = "close";
}
if (!bad_fn && (flags & PEX_STDERR_TO_STDOUT) != 0)
{
if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0)
bad_fn = "dup2";
}
if (!bad_fn)
{
if (env)
/* NOTE: In a standard vfork implementation this clobbers
the parent's copy of environ "too" (in reality there's
only one copy). This is ok as we restore it below. */
environ = (char**) env;
if ((flags & PEX_SEARCH) != 0)
{
execvp (executable, to_ptr32 (argv));
bad_fn = "execvp";
}
else
{
execv (executable, to_ptr32 (argv));
bad_fn = "execv";
}
}
/* Something failed, report an error. We don't use stdio
routines, because we might be here due to a vfork call. */
ssize_t retval = 0;
int eno = errno;
#define writeerr(s) (retval |= write (STDERR_FILE_NO, s, strlen (s)))
writeerr (obj->pname);
writeerr (": error trying to exec '");
@ -665,7 +665,7 @@ pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
writeerr ("': ");
writeerr (bad_fn);
writeerr (": ");
writeerr (xstrerror (err));
writeerr (xstrerror (eno));
writeerr ("\n");
#undef writeerr
@ -677,30 +677,33 @@ pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
default:
/* Parent process. */
{
const char *bad_fn = NULL;
/* Restore environ. Note that the parent either doesn't run
until the child execs/exits (standard vfork behaviour), or
if it does run then vfork is behaving more like fork. In
either case we needn't worry about clobbering the child's
copy of environ. */
environ = save_environ;
/* Restore environ.
Note that the parent either doesn't run until the child execs/exits
(standard vfork behaviour), or if it does run then vfork is behaving
more like fork. In either case we needn't worry about clobbering
the child's copy of environ. */
environ = save_environ;
if (!bad_fn && in != STDIN_FILE_NO)
if (close (in) < 0)
bad_fn = "close";
if (!bad_fn && out != STDOUT_FILE_NO)
if (close (out) < 0)
bad_fn = "close";
if (!bad_fn && errdes != STDERR_FILE_NO)
if (close (errdes) < 0)
bad_fn = "close";
if (!bad_fn && in != STDIN_FILE_NO)
if (close (in) < 0)
bad_fn = "close";
if (!bad_fn && out != STDOUT_FILE_NO)
if (close (out) < 0)
bad_fn = "close";
if (!bad_fn && errdes != STDERR_FILE_NO)
if (close (errdes) < 0)
bad_fn = "close";
if (bad_fn)
{
*err = errno;
*errmsg = bad_fn;
return (pid_t) -1;
}
if (bad_fn)
{
*err = errno;
*errmsg = bad_fn;
return (pid_t) -1;
}
}
return pid;
}