#include #include #include #include #include #include #include "pager.h" #include "run-command.h" #include "sigchain.h" #include "subcmd-config.h" /* * This is split up from the rest of git so that we can do * something different on Windows. */ static int spawned_pager; static int pager_columns; void pager_init(const char *pager_env) { subcmd_config.pager_env = pager_env; } static void pager_preexec(void) { /* * Work around bug in "less" by not starting it until we * have real input */ fd_set in; FD_ZERO(&in); FD_SET(0, &in); select(1, &in, NULL, &in, NULL); setenv("LESS", "FRSX", 0); } static const char *pager_argv[] = { "sh", "-c", NULL, NULL }; static struct child_process pager_process; static void wait_for_pager(void) { fflush(stdout); fflush(stderr); /* signal EOF to pager */ close(1); close(2); finish_command(&pager_process); } static void wait_for_pager_signal(int signo) { wait_for_pager(); sigchain_pop(signo); raise(signo); } void setup_pager(void) { const char *pager = getenv(subcmd_config.pager_env); struct winsize sz; if (!isatty(1)) return; if (ioctl(1, TIOCGWINSZ, &sz) == 0) pager_columns = sz.ws_col; if (!pager) pager = getenv("PAGER"); if (!(pager || access("/usr/bin/pager", X_OK))) pager = "/usr/bin/pager"; if (!(pager || access("/usr/bin/less", X_OK))) pager = "/usr/bin/less"; if (!pager) pager = "cat"; if (!*pager || !strcmp(pager, "cat")) return; spawned_pager = 1; /* means we are emitting to terminal */ /* spawn the pager */ pager_argv[2] = pager; pager_process.argv = pager_argv; pager_process.in = -1; pager_process.preexec_cb = pager_preexec; if (start_command(&pager_process)) return; /* original process continues, but writes to the pipe */ dup2(pager_process.in, 1); if (isatty(2)) dup2(pager_process.in, 2); close(pager_process.in); /* this makes sure that the parent terminates after the pager */ sigchain_push_common(wait_for_pager_signal); atexit(wait_for_pager); } int pager_in_use(void) { return spawned_pager; } int pager_get_columns(void) { char *s; s = getenv("COLUMNS"); if (s) return atoi(s); return (pager_columns ? pager_columns : 80) - 2; } d6feb4a'>diff
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authorTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
committerTejun Heo <tj@kernel.org>2017-01-26 16:47:28 -0500
commit07cd12945551b63ecb1a349d50a6d69d1d6feb4a (patch)
tree75f65eba7eac9277971082a2d5a4cf1370562c0c /tools/objtool
parent7ce7d89f48834cefece7804d38fc5d85382edf77 (diff)
cgroup: don't online subsystems before cgroup_name/path() are operational
While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems before the new cgroup is associated with it kernfs_node. This is fine for cgroup proper but cgroup_name/path() depend on the associated kernfs_node and if a subsystem makes the new cgroup_subsys_state visible, which they're allowed to after onlining, it can lead to NULL dereference. The current code performs cgroup creation and subsystem onlining in cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems visible afterwards. There's no reason to online the subsystems early and we can simply drop cgroup_apply_control_enable() call from cgroup_create() so that the subsystems are onlined and made visible at the same time. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") Cc: stable@vger.kernel.org # v4.6+
Diffstat (limited to 'tools/objtool')