diff options
Diffstat (limited to 'backport-posix-Fix-system-blocks-SIGCHLD-erroneously-BZ-30163.patch')
| -rw-r--r-- | backport-posix-Fix-system-blocks-SIGCHLD-erroneously-BZ-30163.patch | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/backport-posix-Fix-system-blocks-SIGCHLD-erroneously-BZ-30163.patch b/backport-posix-Fix-system-blocks-SIGCHLD-erroneously-BZ-30163.patch new file mode 100644 index 0000000..78bebb6 --- /dev/null +++ b/backport-posix-Fix-system-blocks-SIGCHLD-erroneously-BZ-30163.patch @@ -0,0 +1,290 @@ +From 436a604b7dc741fc76b5a6704c6cd8bb178518e7 Mon Sep 17 00:00:00 2001 +From: Adam Yi <ayi@janestreet.com> +Date: Tue, 7 Mar 2023 07:30:02 -0500 +Subject: [PATCH] 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> +--- + stdlib/tst-system.c | 26 +++++++++++++++++++ + support/Makefile | 2 ++ + support/dtotimespec-time64.c | 27 +++++++++++++++++++ + support/dtotimespec.c | 50 ++++++++++++++++++++++++++++++++++++ + support/shell-container.c | 28 ++++++++++++++++++++ + support/timespec.h | 4 +++ + sysdeps/posix/system.c | 6 ++--- + 7 files changed, 140 insertions(+), 3 deletions(-) + create mode 100644 support/dtotimespec-time64.c + create mode 100644 support/dtotimespec.c + +diff --git a/stdlib/tst-system.c b/stdlib/tst-system.c +index 178808e0..d1413d7c 100644 +--- a/stdlib/tst-system.c ++++ b/stdlib/tst-system.c +@@ -26,6 +26,7 @@ + #include <support/check.h> + #include <support/temp_file.h> + #include <support/support.h> ++#include <support/xthread.h> + #include <support/xunistd.h> + + static char *tmpdir; +@@ -72,6 +73,20 @@ call_system (void *closure) + } + } + ++static void * ++sleep_and_check_sigchld (void *closure) ++{ ++ double *seconds = (double *) closure; ++ char cmd[namemax]; ++ sprintf (cmd, "sleep %lf" , *seconds); ++ TEST_COMPARE (system (cmd), 0); ++ ++ sigset_t blocked = {0}; ++ TEST_COMPARE (sigprocmask (SIG_BLOCK, NULL, &blocked), 0); ++ TEST_COMPARE (sigismember (&blocked, SIGCHLD), 0); ++ return NULL; ++} ++ + static int + do_test (void) + { +@@ -155,6 +170,17 @@ do_test (void) + xchmod (_PATH_BSHELL, st.st_mode); + } + ++ { ++ pthread_t long_sleep_thread = xpthread_create (NULL, ++ sleep_and_check_sigchld, ++ &(double) { 0.2 }); ++ pthread_t short_sleep_thread = xpthread_create (NULL, ++ sleep_and_check_sigchld, ++ &(double) { 0.1 }); ++ xpthread_join (short_sleep_thread); ++ xpthread_join (long_sleep_thread); ++ } ++ + TEST_COMPARE (system (""), 0); + + return 0; +diff --git a/support/Makefile b/support/Makefile +index 724ae6d7..936af554 100644 +--- a/support/Makefile ++++ b/support/Makefile +@@ -32,6 +32,8 @@ libsupport-routines = \ + check_hostent \ + check_netent \ + delayed_exit \ ++ dtotimespec \ ++ dtotimespec-time64 \ + ignore_stderr \ + next_to_fault \ + oom_error \ +diff --git a/support/dtotimespec-time64.c b/support/dtotimespec-time64.c +new file mode 100644 +index 00000000..b3d5e351 +--- /dev/null ++++ b/support/dtotimespec-time64.c +@@ -0,0 +1,27 @@ ++/* Convert double to timespec. 64-bit time support. ++ Copyright (C) 2011-2023 Free Software Foundation, Inc. ++ This file is part of the GNU C Library and is also part of gnulib. ++ Patches to this file should be submitted to both projects. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <time.h> ++ ++#if __TIMESIZE != 64 ++# define timespec __timespec64 ++# define time_t __time64_t ++# define dtotimespec dtotimespec_time64 ++# include "dtotimespec.c" ++#endif +diff --git a/support/dtotimespec.c b/support/dtotimespec.c +new file mode 100644 +index 00000000..cde5b4d7 +--- /dev/null ++++ b/support/dtotimespec.c +@@ -0,0 +1,50 @@ ++/* Convert double to timespec. ++ Copyright (C) 2011-2023 Free Software Foundation, Inc. ++ This file is part of the GNU C Library and is also part of gnulib. ++ Patches to this file should be submitted to both projects. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++/* Convert the double value SEC to a struct timespec. Round toward ++ positive infinity. On overflow, return an extremal value. */ ++ ++#include <support/timespec.h> ++#include <intprops.h> ++ ++struct timespec ++dtotimespec (double sec) ++{ ++ if (sec <= TYPE_MINIMUM (time_t)) ++ return make_timespec (TYPE_MINIMUM (time_t), 0); ++ else if (sec >= 1.0 + TYPE_MAXIMUM (time_t)) ++ return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1); ++ else ++ { ++ time_t s = sec; ++ double frac = TIMESPEC_HZ * (sec - s); ++ long ns = frac; ++ ns += ns < frac; ++ s += ns / TIMESPEC_HZ; ++ ns %= TIMESPEC_HZ; ++ ++ if (ns < 0) ++ { ++ s--; ++ ns += TIMESPEC_HZ; ++ } ++ ++ return make_timespec (s, ns); ++ } ++} +diff --git a/support/shell-container.c b/support/shell-container.c +index b2a4324d..6fe925dc 100644 +--- a/support/shell-container.c ++++ b/support/shell-container.c +@@ -39,6 +39,7 @@ + #include <error.h> + + #include <support/support.h> ++#include <support/timespec.h> + + /* Design considerations + +@@ -171,6 +172,32 @@ 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; +@@ -181,6 +208,7 @@ static struct { + { "cp", copy_func }, + { "exit", exit_func }, + { "kill", kill_func }, ++ { "sleep", sleep_func }, + { NULL, NULL } + }; + +diff --git a/support/timespec.h b/support/timespec.h +index 0478aef5..843a90d6 100644 +--- a/support/timespec.h ++++ b/support/timespec.h +@@ -57,6 +57,8 @@ int support_timespec_check_in_range (struct timespec expected, + struct timespec observed, + double lower_bound, double upper_bound); + ++struct timespec dtotimespec (double sec) __attribute__((const)); ++ + #else + struct timespec __REDIRECT (timespec_add, (struct timespec, struct timespec), + timespec_add_time64); +@@ -82,6 +84,8 @@ int __REDIRECT (support_timespec_check_in_range, (struct timespec expected, + double lower_bound, + double upper_bound), + support_timespec_check_in_range_time64); ++ ++struct timespec __REDIRECT (dtotimespec, (double sec), dtotimespec_time64); + #endif + + /* Check that the timespec on the left represents a time before the +diff --git a/sysdeps/posix/system.c b/sysdeps/posix/system.c +index 48668fb3..b9676abb 100644 +--- a/sysdeps/posix/system.c ++++ b/sysdeps/posix/system.c +@@ -179,16 +179,16 @@ do_system (const char *line) + as if the shell had terminated using _exit(127). */ + status = W_EXITCODE (127, 0); + ++ /* sigaction can not fail with SIGINT/SIGQUIT used with old ++ disposition. Same applies for sigprocmask. */ + DO_LOCK (); + if (SUB_REF () == 0) + { +- /* sigaction can not fail with SIGINT/SIGQUIT used with old +- disposition. Same applies for sigprocmask. */ + __sigaction (SIGINT, &intr, NULL); + __sigaction (SIGQUIT, &quit, NULL); +- __sigprocmask (SIG_SETMASK, &omask, NULL); + } + DO_UNLOCK (); ++ __sigprocmask (SIG_SETMASK, &omask, NULL); + + if (ret != 0) + __set_errno (ret); +-- +2.33.0 + |