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ash: do not set a signal to SIG_DFL if it already is

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function                                             old     new   delta
setsignal                                            312     338     +26

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-08-06 20:06:19 +02:00
parent ed7d118dd0
commit 0f14f41e72
1 changed files with 7 additions and 1 deletions
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8
shell/ash.c
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@ -366,7 +366,7 @@ struct globals_misc {
#define S_DFL 1 /* default signal handling (SIG_DFL) */
#define S_CATCH 2 /* signal is caught */
#define S_IGN 3 /* signal is ignored (SIG_IGN) */
#define S_HARD_IGN 4 /* signal is ignored permanently */
#define S_HARD_IGN 4 /* signal is ignored permanently (it was SIG_IGN on entry to shell) */
/* indicates specified signal received */
uint8_t gotsig[NSIG - 1]; /* offset by 1: "signal" 0 is meaningless */
@ -3566,6 +3566,12 @@ setsignal(int signo)
cur_act = S_IGN; /* don't hard ignore these */
}
}
if (act.sa_handler == SIG_DFL && new_act == S_DFL) {
/* installing SIG_DFL over SIG_DFL is a no-op */
/* saves one sigaction call in each "sh -c SCRIPT" invocation */
*t = S_DFL;
return;
}
}
if (cur_act == S_HARD_IGN || cur_act == new_act)
return;