[PATCH] trap: Preserve parent shell traps for simple commands

Herbert Xu
2024-04-14T07:52:06Z

Traps are reset when subshell is started. When a subshell is
started for a simple command, preserve the parent trap text so
that they can be printed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
src/eval.c | 4 ++--
src/init.h | 2 +-
src/jobs.c | 2 +-
src/mkinit.c | 5 +++--
src/trap.c | 51 +++++++++++++++++++++++++++++++++++++--------------
5 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/src/eval.c b/src/eval.c
index fce5314..a0f4df2 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -491,11 +491,11 @@ evalsubshell(union node *n, int flags)
expredir(n->nredir.redirect);
INTOFF;
if (!backgnd && flags & EV_EXIT && !have_traps()) {
- forkreset();
+ forkreset(0);
goto nofork;
}
jp = makejob(1);
- if (forkshell(jp, n, backgnd) == 0) {
+ if (forkshell(jp, n->nredir.n, backgnd) == 0) {
flags |= EV_EXIT;
if (backgnd)
flags &=~ EV_TESTED;
diff --git a/src/init.h b/src/init.h
index d56fb28..705ffd7 100644
--- a/src/init.h
+++ b/src/init.h
@@ -36,5 +36,5 @@

void init(void);
void exitreset(void);
-void forkreset(void);
+void forkreset(int);
void reset(void);
diff --git a/src/jobs.c b/src/jobs.c
index 2a2fe22..0abdcaa 100644
--- a/src/jobs.c
+++ b/src/jobs.c
@@ -872,7 +872,7 @@ static void forkchild(struct job *jp, union node *n, int mode)
if (!lvforked) {
shlvl++;

- forkreset();
+ forkreset(n && n->type == NCMD);

#if JOBS
/* do job control only in root shell */
diff --git a/src/mkinit.c b/src/mkinit.c
index 9025862..f07e288 100644
--- a/src/mkinit.c
+++ b/src/mkinit.c
@@ -91,6 +91,7 @@ struct event {
char *name; /* name of event (e.g. INIT) */
char *routine; /* name of routine called on event */
char *comment; /* comment describing routine */
+ char *args; /* arguments to routine */
struct text code; /* code for handling event */
};

@@ -128,7 +129,7 @@ char reset[] = "\
struct event event[] = {
{"INIT", "init", init},
{"EXITRESET", "exitreset", exitreset},
- {"FORKRESET", "forkreset", forkreset},
+ {"FORKRESET", "forkreset", forkreset, "int simplecmd"},
{"RESET", "reset", reset},
{NULL, NULL}
};
@@ -388,7 +389,7 @@ output(void)
for (ep = event ; ep->name ; ep++) {
fputs("\n\n\n", fp);
fputs(ep->comment, fp);
- fprintf(fp, "\nvoid\n%s() {\n", ep->routine);
+ fprintf(fp, "\nvoid\n%s(%s) {\n", ep->routine, ep->args ?: "");
writetext(&ep->code, fp);
fprintf(fp, "}\n");
}
diff --git a/src/trap.c b/src/trap.c
index cd84814..4587144 100644
--- a/src/trap.c
+++ b/src/trap.c
@@ -66,7 +66,9 @@

/* trap handler commands */
-MKINIT char *trap[NSIG];
+static char *trap[NSIG];
+/* traps have not been fully cleared */
+static int ptrap;
/* number of non-null traps */
int trapcnt;
/* current value of signal */
@@ -81,6 +83,7 @@ volatile sig_atomic_t gotsigchld;
extern char *signal_names[];

static int decode_signum(const char *);
+MKINIT void clear_traps(int);

#ifdef mkinit
INCLUDE "memalloc.h"
@@ -92,19 +95,7 @@ INIT {
}

FORKRESET {
- char **tp;
-
- INTOFF;
- for (tp = trap ; tp < &trap[NSIG] ; tp++) {
- if (*tp && **tp) { /* trap not NULL or SIG_IGN */
- ckfree(*tp);
- *tp = NULL;
- if (tp != &trap[0])
- setsignal(tp - trap);
- }
- }
- trapcnt = 0;
- INTON;
+ clear_traps(simplecmd);
}
#endif

@@ -133,6 +124,8 @@ trapcmd(int argc, char **argv)
}
return 0;
}
+ if (ptrap)
+ clear_traps(0);
if (!ap[1] || decode_signum(*ap) >= 0)
action = NULL;
else
@@ -168,6 +161,36 @@ trapcmd(int argc, char **argv)

+/*
+ * Clear traps on a fork.
+ */
+
+void clear_traps(int simplecmd)