| From 93e0898c663a533082b5f3c2e7dcce93ec47076d Mon Sep 17 00:00:00 2001 |
| From: Denys Vlasenko <vda.linux@googlemail.com> |
| Date: Thu, 26 Jan 2023 12:56:33 +0100 |
| Subject: [PATCH] shell: fix SIGWINCH and SIGCHLD (in hush) interrupting line |
| input, closes 15256 |
| |
| function old new delta |
| record_pending_signo 32 63 +31 |
| lineedit_read_key 231 224 -7 |
| ------------------------------------------------------------------------------ |
| (add/remove: 0/0 grow/shrink: 1/1 up/down: 31/-7) Total: 24 bytes |
| |
| Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> |
| Upstream: https://git.busybox.net/busybox/commit/?id=93e0898c663a533082b5f3c2e7dcce93ec47076d |
| Signed-off-by: Romain Naour <romain.naour@gmail.com> |
| --- |
| libbb/lineedit.c | 17 ++++++++++------- |
| shell/ash.c | 3 ++- |
| shell/hush.c | 10 ++++++++-- |
| 3 files changed, 20 insertions(+), 10 deletions(-) |
| |
| diff --git a/libbb/lineedit.c b/libbb/lineedit.c |
| index d6b2e76ff..b942f540a 100644 |
| --- a/libbb/lineedit.c |
| +++ b/libbb/lineedit.c |
| @@ -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 */ |
| } |
| } |
| |
| diff --git a/shell/ash.c b/shell/ash.c |
| index 18ccc1329..5f8c8ea19 100644 |
| --- a/shell/ash.c |
| +++ b/shell/ash.c |
| @@ -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 $$; do sleep 1; done) & |
| diff --git a/shell/hush.c b/shell/hush.c |
| index d111f0cc5..f064b8fd2 100644 |
| --- a/shell/hush.c |
| +++ b/shell/hush.c |
| @@ -1946,7 +1946,12 @@ static void record_pending_signo(int sig) |
| { |
| sigaddset(&G.pending_set, sig); |
| #if ENABLE_FEATURE_EDITING |
| - bb_got_signal = sig; /* for read_line_input: "we got a signal" */ |
| + if (sig != SIGCHLD |
| + || (G_traps && G_traps[SIGCHLD] && G_traps[SIGCHLD][0]) |
| + /* ^^^ if SIGCHLD, interrupt line reading only if it has a trap */ |
| + ) { |
| + bb_got_signal = sig; /* for read_line_input: "we got a signal" */ |
| + } |
| #endif |
| #if ENABLE_HUSH_FAST |
| if (sig == SIGCHLD) { |
| @@ -2669,7 +2674,8 @@ static int get_user_input(struct in_str *i) |
| } else { |
| /* For shell, LI_INTERRUPTIBLE is set: |
| * read_line_input will abort on either |
| - * getting EINTR in poll(), or if it sees bb_got_signal != 0 |
| + * getting EINTR in poll() and bb_got_signal became != 0, |
| + * or if it sees bb_got_signal != 0 |
| * (IOW: if signal arrives before poll() is reached). |
| * Interactive testcases: |
| * (while kill -INT $$; do sleep 1; done) & |
| -- |
| 2.30.2 |
| |
