93e0898c6
Denys Vlasenko
2023-01-26
Subject
shell: fix SIGWINCH and SIGCHLD (in hush) interrupting line input, closes 15256
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libbb/lineedit.c+10 -7
| @@ -2180,7 +2180,8 @@ static int lineedit_read_key(char *read_key_buffer, int timeout) | |
| * "\xff\n",pause,"ls\n" invalid and thus won't lose "ls". | |
| * | |
| * If LI_INTERRUPTIBLE, return -1 if got EINTR in poll() | |
| - | * inside read_key, or if bb_got_signal != 0 (IOW: if signal |
| + | * inside read_key and bb_got_signal became != 0, |
| + | * or if bb_got_signal != 0 (IOW: if signal |
| * arrived before poll() is reached). | |
| * | |
| * Note: read_key sets errno to 0 on success. | |
| @@ -2197,14 +2198,16 @@ static int lineedit_read_key(char *read_key_buffer, int timeout) | |
| IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 0;) | |
| if (errno != EINTR) | |
| break; | |
| + | /* It was EINTR. Repeat read_key() unless... */ |
| if (state->flags & LI_INTERRUPTIBLE) { | |
| - | /* LI_INTERRUPTIBLE bails out on EINTR, |
| - | * but nothing really guarantees that bb_got_signal |
| - | * is nonzero. Follow the least surprise principle: |
| + | /* LI_INTERRUPTIBLE bails out on EINTR |
| + | * if bb_got_signal became nonzero. |
| + | * (It may stay zero: for example, our SIGWINCH |
| + | * handler does not set it. This is used for signals |
| + | * which should not interrupt line editing). |
| */ | |
| - | if (bb_got_signal == 0) |
| - | bb_got_signal = 255; |
| - | goto ret; |
| + | if (bb_got_signal != 0) |
| + | goto ret; /* will return -1 */ |
| } | |
| } | |
shell/ash.c+2 -1
| @@ -10821,7 +10821,8 @@ preadfd(void) | |
| again: | |
| /* For shell, LI_INTERRUPTIBLE is set: | |
| * read_line_input will abort on either | |
| - | * getting EINTR in poll(), or if it sees bb_got_signal != 0 |
| + | * getting EINTR in poll() and bb_got_signal became != 0, |
| + | * or if it sees bb_got_signal != 0 |
| * (IOW: if signal arrives before poll() is reached). | |
| * Interactive testcases: | |
| * (while kill -INT $$; do sleep 1; done) & | |
shell/hush.c+8 -2
| @@ -1946,7 +1946,12 @@ static void record_pending_signo(int sig) | |
| { | |
| sigaddset(&G.pending_set, sig); | |
| #if ENABLE_FEATURE_EDITING | |
| - | bb_got_signal = sig; /* for read_line_input: "we got a signal" */ |
| + | if (sig != SIGCHLD |
| + | || (G_traps && G_traps[SIGCHLD] && G_traps[SIGCHLD][0]) |
| + | /* ^^^ if SIGCHLD, interrupt line reading only if it has a trap */ |
| + | ) { |
| + | bb_got_signal = sig; /* for read_line_input: "we got a signal" */ |
| + | } |
| #endif | |
| #if ENABLE_HUSH_FAST | |
| if (sig == SIGCHLD) { | |
| @@ -2669,7 +2674,8 @@ static int get_user_input(struct in_str *i) | |
| } else { | |
| /* For shell, LI_INTERRUPTIBLE is set: | |
| * read_line_input will abort on either | |
| - | * getting EINTR in poll(), or if it sees bb_got_signal != 0 |
| + | * getting EINTR in poll() and bb_got_signal became != 0, |
| + | * or if it sees bb_got_signal != 0 |
| * (IOW: if signal arrives before poll() is reached). | |
| * Interactive testcases: | |
| * (while kill -INT $$; do sleep 1; done) & | |