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author | Adam Yi <ayi@janestreet.com> | 2023-03-07 07:30:02 -0500 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-03-07 09:54:50 -0300 |
commit | 436a604b7dc741fc76b5a6704c6cd8bb178518e7 (patch) | |
tree | 75d6a1a75d91885f4005bf6a17b947b785917e1a /support/shell-container.c | |
parent | 969e9733c7d17edf1e239a73fa172f357561f440 (diff) | |
download | glibc-436a604b7dc741fc76b5a6704c6cd8bb178518e7.tar.gz glibc-436a604b7dc741fc76b5a6704c6cd8bb178518e7.tar.xz glibc-436a604b7dc741fc76b5a6704c6cd8bb178518e7.zip |
posix: Fix system blocks SIGCHLD erroneously [BZ #30163]
Fix bug that SIGCHLD is erroneously blocked forever in the following scenario: 1. Thread A calls system but hasn't returned yet 2. Thread B calls another system but returns SIGCHLD would be blocked forever in thread B after its system() returns, even after the system() in thread A returns. Although POSIX does not require, glibc system implementation aims to be thread and cancellation safe. This bug was introduced in 5fb7fc96350575c9adb1316833e48ca11553be49 when we moved reverting signal mask to happen when the last concurrently running system returns, despite that signal mask is per thread. This commit reverts this logic and adds a test. Signed-off-by: Adam Yi <ayi@janestreet.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'support/shell-container.c')
-rw-r--r-- | support/shell-container.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/support/shell-container.c b/support/shell-container.c index ffa3378b5e..b1f9e793c1 100644 --- a/support/shell-container.c +++ b/support/shell-container.c @@ -37,6 +37,7 @@ #include <error.h> #include <support/support.h> +#include <support/timespec.h> /* Design considerations @@ -169,6 +170,32 @@ kill_func (char **argv) return 0; } +/* Emulate the "/bin/sleep" command. No suffix support. Options are + ignored. */ +static int +sleep_func (char **argv) +{ + if (argv[0] == NULL) + { + fprintf (stderr, "sleep: missing operand\n"); + return 1; + } + char *endptr = NULL; + double sec = strtod (argv[0], &endptr); + if (endptr == argv[0] || errno == ERANGE || sec < 0) + { + fprintf (stderr, "sleep: invalid time interval '%s'\n", argv[0]); + return 1; + } + struct timespec ts = dtotimespec (sec); + if (nanosleep (&ts, NULL) < 0) + { + fprintf (stderr, "sleep: failed to nanosleep: %s\n", strerror (errno)); + return 1; + } + return 0; +} + /* This is a list of all the built-in commands we understand. */ static struct { const char *name; @@ -179,6 +206,7 @@ static struct { { "cp", copy_func }, { "exit", exit_func }, { "kill", kill_func }, + { "sleep", sleep_func }, { NULL, NULL } }; |