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BASH PATCH REPORT
=================
Bash-Release: 5.2
Patch-ID: bash52-015
Bug-Reported-by: Frode Nordahl <frode.nordahl@canonical.com>
Bug-Reference-ID: <20221119070714.351759-1-frode.nordahl@canonical.com>
Bug-Reference-URL: https://lists.gnu.org/archive/html/bug-bash/2022-11/msg00078.html
Bug-Description:
There are several cases where bash is too aggressive when optimizing out forks
in subshells. For example, `eval' and traps should never be optimized.
--- a/builtins/common.h
+++ b/builtins/common.h
@@ -51,6 +51,7 @@ do { \
#define SEVAL_FUNCDEF 0x080 /* only allow function definitions */
#define SEVAL_ONECMD 0x100 /* only allow a single command */
#define SEVAL_NOHISTEXP 0x200 /* inhibit history expansion */
+#define SEVAL_NOOPTIMIZE 0x400 /* don't try to set optimization flags */
/* Flags for describe_command, shared between type.def and command.def */
#define CDESC_ALL 0x001 /* type -a */
--- a/builtins/eval.def
+++ b/builtins/eval.def
@@ -53,5 +53,5 @@ eval_builtin (list)
return (EX_USAGE);
list = loptend; /* skip over possible `--' */
- return (list ? evalstring (string_list (list), "eval", SEVAL_NOHIST) : EXECUTION_SUCCESS);
+ return (list ? evalstring (string_list (list), "eval", SEVAL_NOHIST|SEVAL_NOOPTIMIZE) : EXECUTION_SUCCESS);
}
--- a/builtins/evalstring.c
+++ b/builtins/evalstring.c
@@ -132,8 +132,8 @@ optimize_connection_fork (command)
if (command->type == cm_connection &&
(command->value.Connection->connector == AND_AND || command->value.Connection->connector == OR_OR || command->value.Connection->connector == ';') &&
(command->value.Connection->second->flags & CMD_TRY_OPTIMIZING) &&
- ((startup_state == 2 && should_suppress_fork (command->value.Connection->second)) ||
- ((subshell_environment & SUBSHELL_PAREN) && should_optimize_fork (command->value.Connection->second, 0))))
+ (should_suppress_fork (command->value.Connection->second) ||
+ ((subshell_environment & SUBSHELL_PAREN) && should_optimize_fork (command->value.Connection->second, 0))))
{
command->value.Connection->second->flags |= CMD_NO_FORK;
command->value.Connection->second->value.Simple->flags |= CMD_NO_FORK;
@@ -290,6 +290,7 @@ parse_prologue (string, flags, tag)
(flags & SEVAL_NOFREE) -> don't free STRING when finished
(flags & SEVAL_RESETLINE) -> reset line_number to 1
(flags & SEVAL_NOHISTEXP) -> history_expansion_inhibited -> 1
+ (flags & SEVAL_NOOPTIMIZE) -> don't try to turn on optimizing flags
*/
int
@@ -502,7 +503,9 @@ parse_and_execute (string, from_file, fl
if we are at the end of the command string, the last in a
series of connection commands is
command->value.Connection->second. */
- else if (command->type == cm_connection && can_optimize_connection (command))
+ else if (command->type == cm_connection &&
+ (flags & SEVAL_NOOPTIMIZE) == 0 &&
+ can_optimize_connection (command))
{
command->value.Connection->second->flags |= CMD_TRY_OPTIMIZING;
command->value.Connection->second->value.Simple->flags |= CMD_TRY_OPTIMIZING;
--- a/execute_cmd.c
+++ b/execute_cmd.c
@@ -1654,7 +1654,8 @@ execute_in_subshell (command, asynchrono
subshell sets an exit trap, so we set CMD_NO_FORK for simple commands
and set CMD_TRY_OPTIMIZING for simple commands on the right side of an
and-or or `;' list to test for optimizing forks when they are executed. */
- if (user_subshell && command->type == cm_subshell)
+ if (user_subshell && command->type == cm_subshell &&
+ (command->flags & (CMD_TIME_PIPELINE|CMD_INVERT_RETURN)) == 0)
optimize_subshell_command (command->value.Subshell->command);
/* Do redirections, then dispose of them before recursive call. */
--- a/jobs.c
+++ b/jobs.c
@@ -4220,7 +4220,7 @@ run_sigchld_trap (nchild)
jobs_list_frozen = 1;
for (i = 0; i < nchild; i++)
{
- parse_and_execute (savestring (trap_command), "trap", SEVAL_NOHIST|SEVAL_RESETLINE);
+ parse_and_execute (savestring (trap_command), "trap", SEVAL_NOHIST|SEVAL_RESETLINE|SEVAL_NOOPTIMIZE);
}
run_unwind_frame ("SIGCHLD trap");
--- a/parse.y
+++ b/parse.y
@@ -2827,7 +2827,7 @@ execute_variable_command (command, vname
if (last_lastarg)
last_lastarg = savestring (last_lastarg);
- parse_and_execute (savestring (command), vname, SEVAL_NONINT|SEVAL_NOHIST);
+ parse_and_execute (savestring (command), vname, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_NOOPTIMIZE);
restore_parser_state (&ps);
bind_variable ("_", last_lastarg, 0);
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -25,6 +25,6 @@
regexp `^#define[ ]*PATCHLEVEL', since that's what support/mkversion.sh
looks for to find the patch level (for the sccs version string). */
-#define PATCHLEVEL 14
+#define PATCHLEVEL 15
#endif /* _PATCHLEVEL_H_ */
--- a/trap.c
+++ b/trap.c
@@ -304,6 +304,7 @@ run_pending_traps ()
sh_parser_state_t pstate;
volatile int save_return_catch_flag, function_code;
procenv_t save_return_catch;
+ char *trap_command, *old_trap;
#if defined (ARRAY_VARS)
ARRAY *ps;
#endif
@@ -419,6 +420,9 @@ run_pending_traps ()
}
else
{
+ old_trap = trap_list[sig];
+ trap_command = savestring (old_trap);
+
save_parser_state (&pstate);
save_subst_varlist = subst_assign_varlist;
subst_assign_varlist = 0;
@@ -441,7 +445,8 @@ run_pending_traps ()
}
if (function_code == 0)
- x = parse_and_execute (savestring (trap_list[sig]), "trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE);
+ /* XXX is x always last_command_exit_value? */
+ x = parse_and_execute (trap_command, "trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE|SEVAL_NOOPTIMIZE);
else
{
parse_and_execute_cleanup (sig + 1); /* XXX - could use -1 */
@@ -1002,7 +1007,7 @@ run_exit_trap ()
if (code == 0 && function_code == 0)
{
reset_parser ();
- parse_and_execute (trap_command, "exit trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE);
+ parse_and_execute (trap_command, "exit trap", SEVAL_NONINT|SEVAL_NOHIST|SEVAL_RESETLINE|SEVAL_NOOPTIMIZE);
}
else if (code == ERREXIT)
retval = last_command_exit_value;
@@ -1109,7 +1114,7 @@ _run_trap_internal (sig, tag)
function_code = setjmp_nosigs (return_catch);
}
- flags = SEVAL_NONINT|SEVAL_NOHIST;
+ flags = SEVAL_NONINT|SEVAL_NOHIST|SEVAL_NOOPTIMIZE;
if (sig != DEBUG_TRAP && sig != RETURN_TRAP && sig != ERROR_TRAP)
flags |= SEVAL_RESETLINE;
evalnest++;
--- a/y.tab.c
+++ b/y.tab.c
@@ -5138,7 +5138,7 @@ execute_variable_command (command, vname
if (last_lastarg)
last_lastarg = savestring (last_lastarg);
- parse_and_execute (savestring (command), vname, SEVAL_NONINT|SEVAL_NOHIST);
+ parse_and_execute (savestring (command), vname, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_NOOPTIMIZE);
restore_parser_state (&ps);
bind_variable ("_", last_lastarg, 0);
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