mirror of
https://github.com/torvalds/linux.git
synced 2024-11-06 20:21:57 +00:00
d3a73acbc2
The oi and ni instructions used in entry[64].S to set and clear bits in the thread-flags are not guaranteed to be atomic in regard to other CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific bits. Updates on the TIF bits are done with atomic instructions, updates on CPU and pt_regs bits are done with non-atomic instructions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
428 lines
12 KiB
C
428 lines
12 KiB
C
/*
|
|
* Copyright IBM Corp. 1999, 2006
|
|
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
|
|
*
|
|
* Based on Intel version
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
|
|
*/
|
|
|
|
#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/ptrace.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/binfmts.h>
|
|
#include <linux/tracehook.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/compat.h>
|
|
#include <asm/ucontext.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/lowcore.h>
|
|
#include <asm/switch_to.h>
|
|
#include "entry.h"
|
|
|
|
typedef struct
|
|
{
|
|
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
|
|
struct sigcontext sc;
|
|
_sigregs sregs;
|
|
int signo;
|
|
__u8 retcode[S390_SYSCALL_SIZE];
|
|
} sigframe;
|
|
|
|
typedef struct
|
|
{
|
|
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
|
|
__u8 retcode[S390_SYSCALL_SIZE];
|
|
struct siginfo info;
|
|
struct ucontext uc;
|
|
} rt_sigframe;
|
|
|
|
/* Returns non-zero on fault. */
|
|
static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
|
{
|
|
_sigregs user_sregs;
|
|
|
|
save_access_regs(current->thread.acrs);
|
|
|
|
/* Copy a 'clean' PSW mask to the user to avoid leaking
|
|
information about whether PER is currently on. */
|
|
user_sregs.regs.psw.mask = PSW_USER_BITS |
|
|
(regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
|
|
user_sregs.regs.psw.addr = regs->psw.addr;
|
|
memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
|
|
memcpy(&user_sregs.regs.acrs, current->thread.acrs,
|
|
sizeof(user_sregs.regs.acrs));
|
|
/*
|
|
* We have to store the fp registers to current->thread.fp_regs
|
|
* to merge them with the emulated registers.
|
|
*/
|
|
save_fp_ctl(¤t->thread.fp_regs.fpc);
|
|
save_fp_regs(current->thread.fp_regs.fprs);
|
|
memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
|
|
sizeof(user_sregs.fpregs));
|
|
if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
|
|
{
|
|
_sigregs user_sregs;
|
|
|
|
/* Alwys make any pending restarted system call return -EINTR */
|
|
current_thread_info()->restart_block.fn = do_no_restart_syscall;
|
|
|
|
if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
|
|
return -EFAULT;
|
|
|
|
if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
|
|
return -EINVAL;
|
|
|
|
/* Loading the floating-point-control word can fail. Do that first. */
|
|
if (restore_fp_ctl(&user_sregs.fpregs.fpc))
|
|
return -EINVAL;
|
|
|
|
/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
|
|
regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
|
|
(user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
|
|
/* Check for invalid user address space control. */
|
|
if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
|
|
regs->psw.mask = PSW_ASC_PRIMARY |
|
|
(regs->psw.mask & ~PSW_MASK_ASC);
|
|
/* Check for invalid amode */
|
|
if (regs->psw.mask & PSW_MASK_EA)
|
|
regs->psw.mask |= PSW_MASK_BA;
|
|
regs->psw.addr = user_sregs.regs.psw.addr;
|
|
memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
|
|
memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
|
|
sizeof(current->thread.acrs));
|
|
restore_access_regs(current->thread.acrs);
|
|
|
|
memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
|
|
sizeof(current->thread.fp_regs));
|
|
|
|
restore_fp_regs(current->thread.fp_regs.fprs);
|
|
clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
|
|
return 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE0(sigreturn)
|
|
{
|
|
struct pt_regs *regs = task_pt_regs(current);
|
|
sigframe __user *frame = (sigframe __user *)regs->gprs[15];
|
|
sigset_t set;
|
|
|
|
if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
|
|
goto badframe;
|
|
set_current_blocked(&set);
|
|
if (restore_sigregs(regs, &frame->sregs))
|
|
goto badframe;
|
|
return regs->gprs[2];
|
|
badframe:
|
|
force_sig(SIGSEGV, current);
|
|
return 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE0(rt_sigreturn)
|
|
{
|
|
struct pt_regs *regs = task_pt_regs(current);
|
|
rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
|
|
sigset_t set;
|
|
|
|
if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
|
|
goto badframe;
|
|
set_current_blocked(&set);
|
|
if (restore_sigregs(regs, &frame->uc.uc_mcontext))
|
|
goto badframe;
|
|
if (restore_altstack(&frame->uc.uc_stack))
|
|
goto badframe;
|
|
return regs->gprs[2];
|
|
badframe:
|
|
force_sig(SIGSEGV, current);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set up a signal frame.
|
|
*/
|
|
|
|
|
|
/*
|
|
* Determine which stack to use..
|
|
*/
|
|
static inline void __user *
|
|
get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
|
|
{
|
|
unsigned long sp;
|
|
|
|
/* Default to using normal stack */
|
|
sp = regs->gprs[15];
|
|
|
|
/* Overflow on alternate signal stack gives SIGSEGV. */
|
|
if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
|
|
return (void __user *) -1UL;
|
|
|
|
/* This is the X/Open sanctioned signal stack switching. */
|
|
if (ka->sa.sa_flags & SA_ONSTACK) {
|
|
if (! sas_ss_flags(sp))
|
|
sp = current->sas_ss_sp + current->sas_ss_size;
|
|
}
|
|
|
|
return (void __user *)((sp - frame_size) & -8ul);
|
|
}
|
|
|
|
static inline int map_signal(int sig)
|
|
{
|
|
if (current_thread_info()->exec_domain
|
|
&& current_thread_info()->exec_domain->signal_invmap
|
|
&& sig < 32)
|
|
return current_thread_info()->exec_domain->signal_invmap[sig];
|
|
else
|
|
return sig;
|
|
}
|
|
|
|
static int setup_frame(int sig, struct k_sigaction *ka,
|
|
sigset_t *set, struct pt_regs * regs)
|
|
{
|
|
sigframe __user *frame;
|
|
|
|
frame = get_sigframe(ka, regs, sizeof(sigframe));
|
|
|
|
if (frame == (void __user *) -1UL)
|
|
goto give_sigsegv;
|
|
|
|
if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
|
|
goto give_sigsegv;
|
|
|
|
if (save_sigregs(regs, &frame->sregs))
|
|
goto give_sigsegv;
|
|
if (__put_user(&frame->sregs, &frame->sc.sregs))
|
|
goto give_sigsegv;
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
if (ka->sa.sa_flags & SA_RESTORER) {
|
|
regs->gprs[14] = (unsigned long)
|
|
ka->sa.sa_restorer | PSW_ADDR_AMODE;
|
|
} else {
|
|
regs->gprs[14] = (unsigned long)
|
|
frame->retcode | PSW_ADDR_AMODE;
|
|
if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
|
|
(u16 __user *)(frame->retcode)))
|
|
goto give_sigsegv;
|
|
}
|
|
|
|
/* Set up backchain. */
|
|
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
|
|
goto give_sigsegv;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->gprs[15] = (unsigned long) frame;
|
|
/* Force default amode and default user address space control. */
|
|
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
|
|
(PSW_USER_BITS & PSW_MASK_ASC) |
|
|
(regs->psw.mask & ~PSW_MASK_ASC);
|
|
regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
|
|
|
|
regs->gprs[2] = map_signal(sig);
|
|
regs->gprs[3] = (unsigned long) &frame->sc;
|
|
|
|
/* We forgot to include these in the sigcontext.
|
|
To avoid breaking binary compatibility, they are passed as args. */
|
|
if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
|
|
sig == SIGTRAP || sig == SIGFPE) {
|
|
/* set extra registers only for synchronous signals */
|
|
regs->gprs[4] = regs->int_code & 127;
|
|
regs->gprs[5] = regs->int_parm_long;
|
|
regs->gprs[6] = task_thread_info(current)->last_break;
|
|
}
|
|
|
|
/* Place signal number on stack to allow backtrace from handler. */
|
|
if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
|
|
goto give_sigsegv;
|
|
return 0;
|
|
|
|
give_sigsegv:
|
|
force_sigsegv(sig, current);
|
|
return -EFAULT;
|
|
}
|
|
|
|
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *set, struct pt_regs * regs)
|
|
{
|
|
int err = 0;
|
|
rt_sigframe __user *frame;
|
|
|
|
frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
|
|
|
|
if (frame == (void __user *) -1UL)
|
|
goto give_sigsegv;
|
|
|
|
if (copy_siginfo_to_user(&frame->info, info))
|
|
goto give_sigsegv;
|
|
|
|
/* Create the ucontext. */
|
|
err |= __put_user(0, &frame->uc.uc_flags);
|
|
err |= __put_user(NULL, &frame->uc.uc_link);
|
|
err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
|
|
err |= save_sigregs(regs, &frame->uc.uc_mcontext);
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
if (err)
|
|
goto give_sigsegv;
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
if (ka->sa.sa_flags & SA_RESTORER) {
|
|
regs->gprs[14] = (unsigned long)
|
|
ka->sa.sa_restorer | PSW_ADDR_AMODE;
|
|
} else {
|
|
regs->gprs[14] = (unsigned long)
|
|
frame->retcode | PSW_ADDR_AMODE;
|
|
if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
|
|
(u16 __user *)(frame->retcode)))
|
|
goto give_sigsegv;
|
|
}
|
|
|
|
/* Set up backchain. */
|
|
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
|
|
goto give_sigsegv;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->gprs[15] = (unsigned long) frame;
|
|
/* Force default amode and default user address space control. */
|
|
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
|
|
(PSW_USER_BITS & PSW_MASK_ASC) |
|
|
(regs->psw.mask & ~PSW_MASK_ASC);
|
|
regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
|
|
|
|
regs->gprs[2] = map_signal(sig);
|
|
regs->gprs[3] = (unsigned long) &frame->info;
|
|
regs->gprs[4] = (unsigned long) &frame->uc;
|
|
regs->gprs[5] = task_thread_info(current)->last_break;
|
|
return 0;
|
|
|
|
give_sigsegv:
|
|
force_sigsegv(sig, current);
|
|
return -EFAULT;
|
|
}
|
|
|
|
static void handle_signal(unsigned long sig, struct k_sigaction *ka,
|
|
siginfo_t *info, sigset_t *oldset,
|
|
struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
|
|
/* Set up the stack frame */
|
|
if (ka->sa.sa_flags & SA_SIGINFO)
|
|
ret = setup_rt_frame(sig, ka, info, oldset, regs);
|
|
else
|
|
ret = setup_frame(sig, ka, oldset, regs);
|
|
if (ret)
|
|
return;
|
|
signal_delivered(sig, info, ka, regs,
|
|
test_thread_flag(TIF_SINGLE_STEP));
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* Note that we go through the signals twice: once to check the signals that
|
|
* the kernel can handle, and then we build all the user-level signal handling
|
|
* stack-frames in one go after that.
|
|
*/
|
|
void do_signal(struct pt_regs *regs)
|
|
{
|
|
siginfo_t info;
|
|
int signr;
|
|
struct k_sigaction ka;
|
|
sigset_t *oldset = sigmask_to_save();
|
|
|
|
/*
|
|
* Get signal to deliver. When running under ptrace, at this point
|
|
* the debugger may change all our registers, including the system
|
|
* call information.
|
|
*/
|
|
current_thread_info()->system_call =
|
|
test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0;
|
|
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
|
|
|
|
if (signr > 0) {
|
|
/* Whee! Actually deliver the signal. */
|
|
if (current_thread_info()->system_call) {
|
|
regs->int_code = current_thread_info()->system_call;
|
|
/* Check for system call restarting. */
|
|
switch (regs->gprs[2]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->gprs[2] = -EINTR;
|
|
break;
|
|
case -ERESTARTSYS:
|
|
if (!(ka.sa.sa_flags & SA_RESTART)) {
|
|
regs->gprs[2] = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
regs->gprs[2] = regs->orig_gpr2;
|
|
regs->psw.addr =
|
|
__rewind_psw(regs->psw,
|
|
regs->int_code >> 16);
|
|
break;
|
|
}
|
|
}
|
|
/* No longer in a system call */
|
|
clear_pt_regs_flag(regs, PIF_SYSCALL);
|
|
|
|
if (is_compat_task())
|
|
handle_signal32(signr, &ka, &info, oldset, regs);
|
|
else
|
|
handle_signal(signr, &ka, &info, oldset, regs);
|
|
return;
|
|
}
|
|
|
|
/* No handlers present - check for system call restart */
|
|
clear_pt_regs_flag(regs, PIF_SYSCALL);
|
|
if (current_thread_info()->system_call) {
|
|
regs->int_code = current_thread_info()->system_call;
|
|
switch (regs->gprs[2]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
/* Restart with sys_restart_syscall */
|
|
regs->int_code = __NR_restart_syscall;
|
|
/* fallthrough */
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
/* Restart system call with magic TIF bit. */
|
|
regs->gprs[2] = regs->orig_gpr2;
|
|
set_pt_regs_flag(regs, PIF_SYSCALL);
|
|
if (test_thread_flag(TIF_SINGLE_STEP))
|
|
clear_pt_regs_flag(regs, PIF_PER_TRAP);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask back.
|
|
*/
|
|
restore_saved_sigmask();
|
|
}
|
|
|
|
void do_notify_resume(struct pt_regs *regs)
|
|
{
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|