On Sat, Mar 02, 2019 at 01:28:44PM +0000, Harald van Dijk wrote: > > That is *a* real bug here, not *the* real bug. This leaves the buggy > behaviour of the "command" built-in intact in the test case I included in > the message you replied to.
I don't quite understand. Could you explain what is still buggy after the following patch? > For fixing the one bug, it is a sensible approach, but keep in mind that > when a fork is omitted because of EV_EXIT, so too will the reset of handler. > You may be able to get away with that as long as you do not propagate > EV_EXIT in any cases where a cleanup action might cause problems. Good point. Here is a revised patch to fix the nofork case too. ---8<-- As it is a subshell can execute code that is only meant for the parent shell when it executes a longjmp that is caught by something like evalcommand. This patch fixes it by resetting the handler when entering a subshell. Reported-by: Martijn Dekker <[email protected]> Signed-off-by: Herbert Xu <[email protected]> diff --git a/src/eval.c b/src/eval.c index 1aad31a..6ee2e1a 100644 --- a/src/eval.c +++ b/src/eval.c @@ -41,6 +41,7 @@ * Evaluate a command. */ +#include "main.h" #include "shell.h" #include "nodes.h" #include "syntax.h" @@ -492,6 +493,7 @@ evalsubshell(union node *n, int flags) if (backgnd) flags &=~ EV_TESTED; nofork: + reset_handler(); redirect(n->nredir.redirect, 0); evaltreenr(n->nredir.n, flags); /* never returns */ @@ -574,6 +576,7 @@ evalpipe(union node *n, int flags) } } if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { + reset_handler(); INTON; if (pip[1] >= 0) { close(pip[0]); @@ -630,6 +633,7 @@ evalbackcmd(union node *n, struct backcmd *result) sh_error("Pipe call failed"); jp = makejob(n, 1); if (forkshell(jp, n, FORK_NOJOB) == 0) { + reset_handler(); FORCEINTON; close(pip[0]); if (pip[1] != 1) { diff --git a/src/main.c b/src/main.c index 6b3a090..b2712cb 100644 --- a/src/main.c +++ b/src/main.c @@ -71,6 +71,7 @@ int *dash_errno; short profile_buf[16384]; extern int etext(); #endif +static struct jmploc main_handler; STATIC void read_profile(const char *); STATIC char *find_dot_file(char *); @@ -90,7 +91,6 @@ main(int argc, char **argv) { char *shinit; volatile int state; - struct jmploc jmploc; struct stackmark smark; int login; @@ -102,7 +102,7 @@ main(int argc, char **argv) monitor(4, etext, profile_buf, sizeof profile_buf, 50); #endif state = 0; - if (unlikely(setjmp(jmploc.loc))) { + if (unlikely(setjmp(main_handler.loc))) { int e; int s; @@ -137,7 +137,7 @@ main(int argc, char **argv) else goto state4; } - handler = &jmploc; + handler = &main_handler; #ifdef DEBUG opentrace(); trputs("Shell args: "); trargs(argv); @@ -353,3 +353,8 @@ exitcmd(int argc, char **argv) exraise(EXEXIT); /* NOTREACHED */ } + +void reset_handler(void) +{ + handler = &main_handler; +} diff --git a/src/main.h b/src/main.h index 19e4983..51f1604 100644 --- a/src/main.h +++ b/src/main.h @@ -52,3 +52,4 @@ extern int *dash_errno; void readcmdfile(char *); int dotcmd(int, char **); int exitcmd(int, char **); +void reset_handler(void); -- Email: Herbert Xu <[email protected]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
