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-rw-r--r--kernel/exit.c307
1 files changed, 164 insertions, 143 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index c63226283aef..b0cc86a2d00b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -62,6 +62,7 @@
#include <linux/kcov.h>
#include <linux/random.h>
#include <linux/rcuwait.h>
+#include <linux/compat.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
@@ -982,14 +983,21 @@ SYSCALL_DEFINE1(exit_group, int, error_code)
return 0;
}
+struct waitid_info {
+ pid_t pid;
+ uid_t uid;
+ int status;
+ int cause;
+};
+
struct wait_opts {
enum pid_type wo_type;
int wo_flags;
struct pid *wo_pid;
- struct siginfo __user *wo_info;
- int __user *wo_stat;
- struct rusage __user *wo_rusage;
+ struct waitid_info *wo_info;
+ int wo_stat;
+ struct rusage *wo_rusage;
wait_queue_entry_t child_wait;
int notask_error;
@@ -1036,34 +1044,6 @@ eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
return 1;
}
-static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
- pid_t pid, uid_t uid, int why, int status)
-{
- struct siginfo __user *infop;
- int retval = wo->wo_rusage
- ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
-
- put_task_struct(p);
- infop = wo->wo_info;
- if (infop) {
- if (!retval)
- retval = put_user(SIGCHLD, &infop->si_signo);
- if (!retval)
- retval = put_user(0, &infop->si_errno);
- if (!retval)
- retval = put_user((short)why, &infop->si_code);
- if (!retval)
- retval = put_user(pid, &infop->si_pid);
- if (!retval)
- retval = put_user(uid, &infop->si_uid);
- if (!retval)
- retval = put_user(status, &infop->si_status);
- }
- if (!retval)
- retval = pid;
- return retval;
-}
-
/*
* Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
* read_lock(&tasklist_lock) on entry. If we return zero, we still hold
@@ -1072,30 +1052,23 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
*/
static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
{
- int state, retval, status;
+ int state, status;
pid_t pid = task_pid_vnr(p);
uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
- struct siginfo __user *infop;
+ struct waitid_info *infop;
if (!likely(wo->wo_flags & WEXITED))
return 0;
if (unlikely(wo->wo_flags & WNOWAIT)) {
- int exit_code = p->exit_code;
- int why;
-
+ status = p->exit_code;
get_task_struct(p);
read_unlock(&tasklist_lock);
sched_annotate_sleep();
-
- if ((exit_code & 0x7f) == 0) {
- why = CLD_EXITED;
- status = exit_code >> 8;
- } else {
- why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
- status = exit_code & 0x7f;
- }
- return wait_noreap_copyout(wo, p, pid, uid, why, status);
+ if (wo->wo_rusage)
+ getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+ put_task_struct(p);
+ goto out_info;
}
/*
* Move the task's state to DEAD/TRACE, only one thread can do this.
@@ -1168,38 +1141,11 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
spin_unlock_irq(&current->sighand->siglock);
}
- retval = wo->wo_rusage
- ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
+ if (wo->wo_rusage)
+ getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
- if (!retval && wo->wo_stat)
- retval = put_user(status, wo->wo_stat);
-
- infop = wo->wo_info;
- if (!retval && infop)
- retval = put_user(SIGCHLD, &infop->si_signo);
- if (!retval && infop)
- retval = put_user(0, &infop->si_errno);
- if (!retval && infop) {
- int why;
-
- if ((status & 0x7f) == 0) {
- why = CLD_EXITED;
- status >>= 8;
- } else {
- why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
- status &= 0x7f;
- }
- retval = put_user((short)why, &infop->si_code);
- if (!retval)
- retval = put_user(status, &infop->si_status);
- }
- if (!retval && infop)
- retval = put_user(pid, &infop->si_pid);
- if (!retval && infop)
- retval = put_user(uid, &infop->si_uid);
- if (!retval)
- retval = pid;
+ wo->wo_stat = status;
if (state == EXIT_TRACE) {
write_lock_irq(&tasklist_lock);
@@ -1216,7 +1162,21 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
if (state == EXIT_DEAD)
release_task(p);
- return retval;
+out_info:
+ infop = wo->wo_info;
+ if (infop) {
+ if ((status & 0x7f) == 0) {
+ infop->cause = CLD_EXITED;
+ infop->status = status >> 8;
+ } else {
+ infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+ infop->status = status & 0x7f;
+ }
+ infop->pid = pid;
+ infop->uid = uid;
+ }
+
+ return pid;
}
static int *task_stopped_code(struct task_struct *p, bool ptrace)
@@ -1252,8 +1212,8 @@ static int *task_stopped_code(struct task_struct *p, bool ptrace)
static int wait_task_stopped(struct wait_opts *wo,
int ptrace, struct task_struct *p)
{
- struct siginfo __user *infop;
- int retval, exit_code, *p_code, why;
+ struct waitid_info *infop;
+ int exit_code, *p_code, why;
uid_t uid = 0; /* unneeded, required by compiler */
pid_t pid;
@@ -1298,34 +1258,21 @@ unlock_sig:
why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
sched_annotate_sleep();
+ if (wo->wo_rusage)
+ getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+ put_task_struct(p);
- if (unlikely(wo->wo_flags & WNOWAIT))
- return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);
-
- retval = wo->wo_rusage
- ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
- if (!retval && wo->wo_stat)
- retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
+ if (likely(!(wo->wo_flags & WNOWAIT)))
+ wo->wo_stat = (exit_code << 8) | 0x7f;
infop = wo->wo_info;
- if (!retval && infop)
- retval = put_user(SIGCHLD, &infop->si_signo);
- if (!retval && infop)
- retval = put_user(0, &infop->si_errno);
- if (!retval && infop)
- retval = put_user((short)why, &infop->si_code);
- if (!retval && infop)
- retval = put_user(exit_code, &infop->si_status);
- if (!retval && infop)
- retval = put_user(pid, &infop->si_pid);
- if (!retval && infop)
- retval = put_user(uid, &infop->si_uid);
- if (!retval)
- retval = pid;
- put_task_struct(p);
-
- BUG_ON(!retval);
- return retval;
+ if (infop) {
+ infop->cause = why;
+ infop->status = exit_code;
+ infop->pid = pid;
+ infop->uid = uid;
+ }
+ return pid;
}
/*
@@ -1336,7 +1283,7 @@ unlock_sig:
*/
static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
{
- int retval;
+ struct waitid_info *infop;
pid_t pid;
uid_t uid;
@@ -1361,22 +1308,20 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
get_task_struct(p);
read_unlock(&tasklist_lock);
sched_annotate_sleep();
+ if (wo->wo_rusage)
+ getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
+ put_task_struct(p);
- if (!wo->wo_info) {
- retval = wo->wo_rusage
- ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
- put_task_struct(p);
- if (!retval && wo->wo_stat)
- retval = put_user(0xffff, wo->wo_stat);
- if (!retval)
- retval = pid;
+ infop = wo->wo_info;
+ if (!infop) {
+ wo->wo_stat = 0xffff;
} else {
- retval = wait_noreap_copyout(wo, p, pid, uid,
- CLD_CONTINUED, SIGCONT);
- BUG_ON(retval == 0);
+ infop->cause = CLD_CONTINUED;
+ infop->pid = pid;
+ infop->uid = uid;
+ infop->status = SIGCONT;
}
-
- return retval;
+ return pid;
}
/*
@@ -1604,8 +1549,8 @@ end:
return retval;
}
-SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
- infop, int, options, struct rusage __user *, ru)
+static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
+ int options, struct rusage *ru)
{
struct wait_opts wo;
struct pid *pid = NULL;
@@ -1643,38 +1588,46 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
wo.wo_pid = pid;
wo.wo_flags = options;
wo.wo_info = infop;
- wo.wo_stat = NULL;
wo.wo_rusage = ru;
ret = do_wait(&wo);
- if (ret > 0) {
+ if (ret > 0)
ret = 0;
- } else if (infop) {
- /*
- * For a WNOHANG return, clear out all the fields
- * we would set so the user can easily tell the
- * difference.
- */
- if (!ret)
- ret = put_user(0, &infop->si_signo);
- if (!ret)
- ret = put_user(0, &infop->si_errno);
- if (!ret)
- ret = put_user(0, &infop->si_code);
- if (!ret)
- ret = put_user(0, &infop->si_pid);
- if (!ret)
- ret = put_user(0, &infop->si_uid);
- if (!ret)
- ret = put_user(0, &infop->si_status);
- }
put_pid(pid);
return ret;
}
-SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
- int, options, struct rusage __user *, ru)
+SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
+ infop, int, options, struct rusage __user *, ru)
+{
+ struct rusage r;
+ struct waitid_info info = {.status = 0};
+ long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
+
+ if (!err) {
+ if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
+ return -EFAULT;
+ }
+ if (!infop)
+ return err;
+
+ user_access_begin();
+ unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+ unsafe_put_user(0, &infop->si_errno, Efault);
+ unsafe_put_user((short)info.cause, &infop->si_code, Efault);
+ unsafe_put_user(info.pid, &infop->si_pid, Efault);
+ unsafe_put_user(info.uid, &infop->si_uid, Efault);
+ unsafe_put_user(info.status, &infop->si_status, Efault);
+ user_access_end();
+ return err;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+
+long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
+ struct rusage *ru)
{
struct wait_opts wo;
struct pid *pid = NULL;
@@ -1702,14 +1655,29 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
wo.wo_pid = pid;
wo.wo_flags = options | WEXITED;
wo.wo_info = NULL;
- wo.wo_stat = stat_addr;
+ wo.wo_stat = 0;
wo.wo_rusage = ru;
ret = do_wait(&wo);
put_pid(pid);
+ if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
+ ret = -EFAULT;
return ret;
}
+SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
+ int, options, struct rusage __user *, ru)
+{
+ struct rusage r;
+ long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
+
+ if (err > 0) {
+ if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
+ return -EFAULT;
+ }
+ return err;
+}
+
#ifdef __ARCH_WANT_SYS_WAITPID
/*
@@ -1722,3 +1690,56 @@ SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
}
#endif
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(wait4,
+ compat_pid_t, pid,
+ compat_uint_t __user *, stat_addr,
+ int, options,
+ struct compat_rusage __user *, ru)
+{
+ struct rusage r;
+ long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
+ if (err > 0) {
+ if (ru && put_compat_rusage(&r, ru))
+ return -EFAULT;
+ }
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE5(waitid,
+ int, which, compat_pid_t, pid,
+ struct compat_siginfo __user *, infop, int, options,
+ struct compat_rusage __user *, uru)
+{
+ struct rusage ru;
+ struct waitid_info info = {.status = 0};
+ long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
+
+ if (!err && uru) {
+ /* kernel_waitid() overwrites everything in ru */
+ if (COMPAT_USE_64BIT_TIME)
+ err = copy_to_user(uru, &ru, sizeof(ru));
+ else
+ err = put_compat_rusage(&ru, uru);
+ if (err)
+ return -EFAULT;
+ }
+
+ if (!infop)
+ return err;
+
+ user_access_begin();
+ unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);
+ unsafe_put_user(0, &infop->si_errno, Efault);
+ unsafe_put_user((short)info.cause, &infop->si_code, Efault);
+ unsafe_put_user(info.pid, &infop->si_pid, Efault);
+ unsafe_put_user(info.uid, &infop->si_uid, Efault);
+ unsafe_put_user(info.status, &infop->si_status, Efault);
+ user_access_end();
+ return err;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 22:41:57 +0000