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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-24 13:22:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-24 13:22:39 +0300
commitba9f6f8954afa5224e3ed60332f7b92242b7ed0f (patch)
treee6513afc476231dc2242728ffbf51353936b46af /include/linux/sched
parenta978a5b8d83f795e107a2ff759b28643739be70e (diff)
parenta36700589b85443e28170be59fa11c8a104130a5 (diff)
downloadlinux-ba9f6f8954afa5224e3ed60332f7b92242b7ed0f.tar.xz
Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman: "I have been slowly sorting out siginfo and this is the culmination of that work. The primary result is in several ways the signal infrastructure has been made less error prone. The code has been updated so that manually specifying SEND_SIG_FORCED is never necessary. The conversion to the new siginfo sending functions is now complete, which makes it difficult to send a signal without filling in the proper siginfo fields. At the tail end of the patchset comes the optimization of decreasing the size of struct siginfo in the kernel from 128 bytes to about 48 bytes on 64bit. The fundamental observation that enables this is by definition none of the known ways to use struct siginfo uses the extra bytes. This comes at the cost of a small user space observable difference. For the rare case of siginfo being injected into the kernel only what can be copied into kernel_siginfo is delivered to the destination, the rest of the bytes are set to 0. For cases where the signal and the si_code are known this is safe, because we know those bytes are not used. For cases where the signal and si_code combination is unknown the bits that won't fit into struct kernel_siginfo are tested to verify they are zero, and the send fails if they are not. I made an extensive search through userspace code and I could not find anything that would break because of the above change. If it turns out I did break something it will take just the revert of a single change to restore kernel_siginfo to the same size as userspace siginfo. Testing did reveal dependencies on preferring the signo passed to sigqueueinfo over si->signo, so bit the bullet and added the complexity necessary to handle that case. Testing also revealed bad things can happen if a negative signal number is passed into the system calls. Something no sane application will do but something a malicious program or a fuzzer might do. So I have fixed the code that performs the bounds checks to ensure negative signal numbers are handled" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (80 commits) signal: Guard against negative signal numbers in copy_siginfo_from_user32 signal: Guard against negative signal numbers in copy_siginfo_from_user signal: In sigqueueinfo prefer sig not si_signo signal: Use a smaller struct siginfo in the kernel signal: Distinguish between kernel_siginfo and siginfo signal: Introduce copy_siginfo_from_user and use it's return value signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE signal: Fail sigqueueinfo if si_signo != sig signal/sparc: Move EMT_TAGOVF into the generic siginfo.h signal/unicore32: Use force_sig_fault where appropriate signal/unicore32: Generate siginfo in ucs32_notify_die signal/unicore32: Use send_sig_fault where appropriate signal/arc: Use force_sig_fault where appropriate signal/arc: Push siginfo generation into unhandled_exception signal/ia64: Use force_sig_fault where appropriate signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn signal/ia64: Use the generic force_sigsegv in setup_frame signal/arm/kvm: Use send_sig_mceerr signal/arm: Use send_sig_fault where appropriate signal/arm: Use force_sig_fault where appropriate ...
Diffstat (limited to 'include/linux/sched')
-rw-r--r--include/linux/sched/signal.h23
1 files changed, 11 insertions, 12 deletions
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 1be35729c2c5..13789d10a50e 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -270,16 +270,16 @@ static inline int signal_group_exit(const struct signal_struct *sig)
extern void flush_signals(struct task_struct *);
extern void ignore_signals(struct task_struct *);
extern void flush_signal_handlers(struct task_struct *, int force_default);
-extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
+extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, kernel_siginfo_t *info);
-static inline int kernel_dequeue_signal(siginfo_t *info)
+static inline int kernel_dequeue_signal(void)
{
struct task_struct *tsk = current;
- siginfo_t __info;
+ kernel_siginfo_t __info;
int ret;
spin_lock_irq(&tsk->sighand->siglock);
- ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
+ ret = dequeue_signal(tsk, &tsk->blocked, &__info);
spin_unlock_irq(&tsk->sighand->siglock);
return ret;
@@ -322,12 +322,12 @@ int force_sig_pkuerr(void __user *addr, u32 pkey);
int force_sig_ptrace_errno_trap(int errno, void __user *addr);
-extern int send_sig_info(int, struct siginfo *, struct task_struct *);
+extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
extern void force_sigsegv(int sig, struct task_struct *p);
-extern int force_sig_info(int, struct siginfo *, struct task_struct *);
-extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
-extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
-extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
+extern int force_sig_info(int, struct kernel_siginfo *, struct task_struct *);
+extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
+extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
+extern int kill_pid_info_as_cred(int, struct kernel_siginfo *, struct pid *,
const struct cred *);
extern int kill_pgrp(struct pid *pid, int sig, int priv);
extern int kill_pid(struct pid *pid, int sig, int priv);
@@ -475,9 +475,8 @@ static inline int kill_cad_pid(int sig, int priv)
}
/* These can be the second arg to send_sig_info/send_group_sig_info. */
-#define SEND_SIG_NOINFO ((struct siginfo *) 0)
-#define SEND_SIG_PRIV ((struct siginfo *) 1)
-#define SEND_SIG_FORCED ((struct siginfo *) 2)
+#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
+#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
/*
* True if we are on the alternate signal stack.