42c4b2e3b
Denys Vlasenko
2010-05-18
Subject
ash: fix var_leak.tests so that it actually catches the NOFORK bug
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/ash.c +14 -8shell/ash_test/ash-vars/var_leak.right +1 -0shell/ash_test/ash-vars/var_leak.tests +6 -1
shell/ash.c+14 -8
| @@ -9179,12 +9179,14 @@ evalcommand(union node *cmd, int flags) | |
| /* Execute the command. */ | |
| switch (cmdentry.cmdtype) { | |
| - | default: |
| + | default: { |
| #if ENABLE_FEATURE_SH_NOFORK | |
| - | /* Hmmm... shouldn't it happen somewhere in forkshell() instead? |
| - | * Why "fork off a child process if necessary" doesn't apply to NOFORK? */ |
| - | { |
| + | /* (1) BUG: if variables are set, we need to fork, or save/restore them |
| + | * around run_nofork_applet() call. |
| + | * (2) Should this check also be done in forkshell()? |
| + | * (perhaps it should, so that "VAR=VAL nofork" at least avoids exec...) |
| + | */ |
| /* find_command() encodes applet_no as (-2 - applet_no) */ | |
| int applet_no = (- cmdentry.u.index - 2); | |
| if (applet_no >= 0 && APPLET_IS_NOFORK(applet_no)) { | |
| @@ -9193,10 +9195,13 @@ evalcommand(union node *cmd, int flags) | |
| exitstatus = run_nofork_applet(applet_no, argv); | |
| break; | |
| } | |
| - | } |
| #endif | |
| - | /* Fork off a child process if necessary. */ |
| + | /* Can we avoid forking off? For example, very last command |
| + | * in a script or a subshell does not need forking, |
| + | * we can just exec it. |
| + | */ |
| if (!(flags & EV_EXIT) || may_have_traps) { | |
| + | /* No, forking off a child is necessary */ |
| INT_OFF; | |
| jp = makejob(/*cmd,*/ 1); | |
| if (forkshell(jp, cmd, FORK_FG) != 0) { | |
| @@ -9213,7 +9218,7 @@ evalcommand(union node *cmd, int flags) | |
| listsetvar(varlist.list, VEXPORT|VSTACK); | |
| shellexec(argv, path, cmdentry.u.index); | |
| /* NOTREACHED */ | |
| - | |
| + | } /* default */ |
| case CMDBUILTIN: | |
| cmdenviron = varlist.list; | |
| if (cmdenviron) { | |
| @@ -9258,7 +9263,8 @@ evalcommand(union node *cmd, int flags) | |
| if (evalfun(cmdentry.u.func, argc, argv, flags)) | |
| goto raise; | |
| break; | |
| - | } |
| + | |
| + | } /* switch */ |
| out: | |
| popredir(/*drop:*/ cmd_is_exec, /*restore:*/ cmd_is_exec); | |
shell/ash_test/ash-vars/var_leak.right+1 -0
| @@ -1,3 +1,4 @@ | |
| should be empty: '' | |
| + | should be empty: '' |
| should be not empty: 'val2' | |
| should be not empty: 'val3' | |
shell/ash_test/ash-vars/var_leak.tests+6 -1
| @@ -1,6 +1,11 @@ | |
| - | # true is a regular builtin, varibale should not leak out of it |
| + | # cat is an external program, variable should not leak out of it. |
| # this currently fails with CONFIG_FEATURE_SH_NOFORK=y | |
| VAR='' | |
| + | VAR=val0 cat /dev/null |
| + | echo "should be empty: '$VAR'" |
| + | |
| + | # true is a regular builtin, variable should not leak out of it. |
| + | VAR='' |
| VAR=val1 true | |
| echo "should be empty: '$VAR'" | |