OpenCloudOS-Kernel/arch/m32r/kernel/signal.c

397 lines
9.1 KiB
C
Raw Normal View History

/*
* linux/arch/m32r/kernel/signal.c
*
* Copyright (c) 2003 Hitoshi Yamamoto
*
* Taken from i386 version.
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/freezer.h>
#include <linux/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#define DEBUG_SIG 0
asmlinkage int
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->spu);
}
/*
* Do a signal return; undo the signal stack.
*/
struct rt_sigframe
{
int sig;
struct siginfo __user *pinfo;
void __user *puc;
struct siginfo info;
struct ucontext uc;
// struct _fpstate fpstate;
};
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
int *r0_p)
{
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
/* COPY(r0); Skip r0 */
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(acc0h);
COPY(acc0l);
COPY(acc1h); /* ISA_DSP_LEVEL2 only */
COPY(acc1l); /* ISA_DSP_LEVEL2 only */
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
regs->syscall_nr = -1; /* disable syscall checks */
err |= __get_user(*r0_p, &sc->sc_r0);
return err;
}
asmlinkage int
sys_rt_sigreturn(unsigned long r0, unsigned long r1,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
sigset_t set;
int result;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
goto badframe;
return result;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
COPY(r0);
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(acc0h);
COPY(acc0l);
COPY(acc1h); /* ISA_DSP_LEVEL2 only */
COPY(acc1l); /* ISA_DSP_LEVEL2 only */
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
return (void __user *)((sp - frame_size) & -8ul);
}
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->spu, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= __put_user(signal, &frame->sig);
if (err)
goto give_sigsegv;
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, info);
if (err)
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->spu),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. */
regs->lr = (unsigned long)ka->sa.sa_restorer;
/* Set up registers for signal handler */
regs->spu = (unsigned long)frame;
regs->r0 = signal; /* Arg for signal handler */
regs->r1 = (unsigned long)&frame->info;
regs->r2 = (unsigned long)&frame->uc;
regs->bpc = (unsigned long)ka->sa.sa_handler;
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
current->comm, current->pid, frame, regs->pc);
#endif
return;
give_sigsegv:
force_sigsegv(sig, current);
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *oldset, struct pt_regs *regs)
{
unsigned short inst;
/* Are we from a system call? */
if (regs->syscall_nr >= 0) {
/* If so, check system call restarting.. */
switch (regs->r0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->r0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->r0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->r0 = regs->orig_r0;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
}
/* Set up the stack frame */
setup_rt_frame(sig, ka, info, oldset, regs);
2005-08-29 23:44:09 +08:00
spin_lock_irq(&current->sighand->siglock);
sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
if (!(ka->sa.sa_flags & SA_NODEFER))
sigaddset(&current->blocked,sig);
2005-08-29 23:44:09 +08:00
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*/
static int do_signal(struct pt_regs *regs)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
unsigned short inst;
sigset_t *oldset;
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return 1;
if (try_to_freeze())
goto no_signal;
if (test_thread_flag(TIF_RESTORE_SIGMASK))
oldset = &current->saved_sigmask;
else
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Re-enable any watchpoints before delivering the
* signal to user space. The processor register will
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
/* Whee! Actually deliver the signal. */
handle_signal(signr, &ka, &info, oldset, regs);
clear_thread_flag(TIF_RESTORE_SIGMASK);
return 1;
}
no_signal:
/* Did we come from a system call? */
if (regs->syscall_nr >= 0) {
/* Restart the system call - no handlers present */
if (regs->r0 == -ERESTARTNOHAND ||
regs->r0 == -ERESTARTSYS ||
regs->r0 == -ERESTARTNOINTR) {
regs->r0 = regs->orig_r0;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
if (regs->r0 == -ERESTART_RESTARTBLOCK){
regs->r0 = regs->orig_r0;
regs->r7 = __NR_restart_syscall;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
}
if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
}
return 0;
}
/*
* notification of userspace execution resumption
* - triggered by current->work.notify_resume
*/
void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
{
/* Pending single-step? */
if (thread_info_flags & _TIF_SINGLESTEP)
clear_thread_flag(TIF_SINGLESTEP);
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include <stdio.h> #include <stdlib.h> #include <keyutils.h> #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 16:14:21 +08:00
if (current->replacement_session_keyring)
key_replace_session_keyring();
}
clear_thread_flag(TIF_IRET);
}