382 lines
10 KiB
C
382 lines
10 KiB
C
/*
|
|
* Common signal handling code for both 32 and 64 bits
|
|
*
|
|
* Copyright (c) 2007 Benjamin Herrenschmidt, IBM Corporation
|
|
* Extracted from signal_32.c and signal_64.c
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General
|
|
* Public License. See the file README.legal in the main directory of
|
|
* this archive for more details.
|
|
*/
|
|
|
|
#include <linux/tracehook.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/uprobes.h>
|
|
#include <linux/key.h>
|
|
#include <linux/context_tracking.h>
|
|
#include <linux/livepatch.h>
|
|
#include <linux/syscalls.h>
|
|
#include <asm/hw_breakpoint.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/switch_to.h>
|
|
#include <asm/unistd.h>
|
|
#include <asm/debug.h>
|
|
#include <asm/tm.h>
|
|
|
|
#include "signal.h"
|
|
|
|
#ifdef CONFIG_VSX
|
|
unsigned long copy_fpr_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
u64 buf[ELF_NFPREG];
|
|
int i;
|
|
|
|
/* save FPR copy to local buffer then write to the thread_struct */
|
|
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
|
|
buf[i] = task->thread.TS_FPR(i);
|
|
buf[i] = task->thread.fp_state.fpscr;
|
|
return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
|
|
}
|
|
|
|
unsigned long copy_fpr_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
u64 buf[ELF_NFPREG];
|
|
int i;
|
|
|
|
if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
|
|
return 1;
|
|
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
|
|
task->thread.TS_FPR(i) = buf[i];
|
|
task->thread.fp_state.fpscr = buf[i];
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned long copy_vsx_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
u64 buf[ELF_NVSRHALFREG];
|
|
int i;
|
|
|
|
/* save FPR copy to local buffer then write to the thread_struct */
|
|
for (i = 0; i < ELF_NVSRHALFREG; i++)
|
|
buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
|
|
return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
|
|
}
|
|
|
|
unsigned long copy_vsx_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
u64 buf[ELF_NVSRHALFREG];
|
|
int i;
|
|
|
|
if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
|
|
return 1;
|
|
for (i = 0; i < ELF_NVSRHALFREG ; i++)
|
|
task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
unsigned long copy_ckfpr_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
u64 buf[ELF_NFPREG];
|
|
int i;
|
|
|
|
/* save FPR copy to local buffer then write to the thread_struct */
|
|
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
|
|
buf[i] = task->thread.TS_CKFPR(i);
|
|
buf[i] = task->thread.ckfp_state.fpscr;
|
|
return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
|
|
}
|
|
|
|
unsigned long copy_ckfpr_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
u64 buf[ELF_NFPREG];
|
|
int i;
|
|
|
|
if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
|
|
return 1;
|
|
for (i = 0; i < (ELF_NFPREG - 1) ; i++)
|
|
task->thread.TS_CKFPR(i) = buf[i];
|
|
task->thread.ckfp_state.fpscr = buf[i];
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned long copy_ckvsx_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
u64 buf[ELF_NVSRHALFREG];
|
|
int i;
|
|
|
|
/* save FPR copy to local buffer then write to the thread_struct */
|
|
for (i = 0; i < ELF_NVSRHALFREG; i++)
|
|
buf[i] = task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
|
|
return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
|
|
}
|
|
|
|
unsigned long copy_ckvsx_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
u64 buf[ELF_NVSRHALFREG];
|
|
int i;
|
|
|
|
if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
|
|
return 1;
|
|
for (i = 0; i < ELF_NVSRHALFREG ; i++)
|
|
task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
|
|
#else
|
|
inline unsigned long copy_fpr_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
return __copy_to_user(to, task->thread.fp_state.fpr,
|
|
ELF_NFPREG * sizeof(double));
|
|
}
|
|
|
|
inline unsigned long copy_fpr_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
return __copy_from_user(task->thread.fp_state.fpr, from,
|
|
ELF_NFPREG * sizeof(double));
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
inline unsigned long copy_ckfpr_to_user(void __user *to,
|
|
struct task_struct *task)
|
|
{
|
|
return __copy_to_user(to, task->thread.ckfp_state.fpr,
|
|
ELF_NFPREG * sizeof(double));
|
|
}
|
|
|
|
inline unsigned long copy_ckfpr_from_user(struct task_struct *task,
|
|
void __user *from)
|
|
{
|
|
return __copy_from_user(task->thread.ckfp_state.fpr, from,
|
|
ELF_NFPREG * sizeof(double));
|
|
}
|
|
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
|
|
#endif
|
|
|
|
/* Log an error when sending an unhandled signal to a process. Controlled
|
|
* through debug.exception-trace sysctl.
|
|
*/
|
|
|
|
int show_unhandled_signals = 1;
|
|
|
|
/*
|
|
* Allocate space for the signal frame
|
|
*/
|
|
void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
|
|
size_t frame_size, int is_32)
|
|
{
|
|
unsigned long oldsp, newsp;
|
|
|
|
/* Default to using normal stack */
|
|
oldsp = get_clean_sp(sp, is_32);
|
|
oldsp = sigsp(oldsp, ksig);
|
|
newsp = (oldsp - frame_size) & ~0xFUL;
|
|
|
|
/* Check access */
|
|
if (!access_ok((void __user *)newsp, oldsp - newsp))
|
|
return NULL;
|
|
|
|
return (void __user *)newsp;
|
|
}
|
|
|
|
static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
|
|
int has_handler)
|
|
{
|
|
unsigned long ret = regs->gpr[3];
|
|
int restart = 1;
|
|
|
|
/* syscall ? */
|
|
if (!trap_is_syscall(regs))
|
|
return;
|
|
|
|
if (trap_norestart(regs))
|
|
return;
|
|
|
|
/* error signalled ? */
|
|
if (trap_is_scv(regs)) {
|
|
/* 32-bit compat mode sign extend? */
|
|
if (!IS_ERR_VALUE(ret))
|
|
return;
|
|
ret = -ret;
|
|
} else if (!(regs->ccr & 0x10000000)) {
|
|
return;
|
|
}
|
|
|
|
switch (ret) {
|
|
case ERESTART_RESTARTBLOCK:
|
|
case ERESTARTNOHAND:
|
|
/* ERESTARTNOHAND means that the syscall should only be
|
|
* restarted if there was no handler for the signal, and since
|
|
* we only get here if there is a handler, we dont restart.
|
|
*/
|
|
restart = !has_handler;
|
|
break;
|
|
case ERESTARTSYS:
|
|
/* ERESTARTSYS means to restart the syscall if there is no
|
|
* handler or the handler was registered with SA_RESTART
|
|
*/
|
|
restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
|
|
break;
|
|
case ERESTARTNOINTR:
|
|
/* ERESTARTNOINTR means that the syscall should be
|
|
* called again after the signal handler returns.
|
|
*/
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
if (restart) {
|
|
if (ret == ERESTART_RESTARTBLOCK)
|
|
regs->gpr[0] = __NR_restart_syscall;
|
|
else
|
|
regs->gpr[3] = regs->orig_gpr3;
|
|
regs->nip -= 4;
|
|
regs->result = 0;
|
|
} else {
|
|
if (trap_is_scv(regs)) {
|
|
regs->result = -EINTR;
|
|
regs->gpr[3] = -EINTR;
|
|
} else {
|
|
regs->result = -EINTR;
|
|
regs->gpr[3] = EINTR;
|
|
regs->ccr |= 0x10000000;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void do_signal(struct task_struct *tsk)
|
|
{
|
|
sigset_t *oldset = sigmask_to_save();
|
|
struct ksignal ksig = { .sig = 0 };
|
|
int ret;
|
|
|
|
BUG_ON(tsk != current);
|
|
|
|
get_signal(&ksig);
|
|
|
|
/* Is there any syscall restart business here ? */
|
|
check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);
|
|
|
|
if (ksig.sig <= 0) {
|
|
/* No signal to deliver -- put the saved sigmask back */
|
|
restore_saved_sigmask();
|
|
set_trap_norestart(tsk->thread.regs);
|
|
return; /* no signals delivered */
|
|
}
|
|
|
|
/*
|
|
* Reenable the DABR before delivering the signal to
|
|
* user space. The DABR will have been cleared if it
|
|
* triggered inside the kernel.
|
|
*/
|
|
if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
|
|
int i;
|
|
|
|
for (i = 0; i < nr_wp_slots(); i++) {
|
|
if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
|
|
__set_breakpoint(i, &tsk->thread.hw_brk[i]);
|
|
}
|
|
}
|
|
|
|
/* Re-enable the breakpoints for the signal stack */
|
|
thread_change_pc(tsk, tsk->thread.regs);
|
|
|
|
rseq_signal_deliver(&ksig, tsk->thread.regs);
|
|
|
|
if (is_32bit_task()) {
|
|
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
|
|
ret = handle_rt_signal32(&ksig, oldset, tsk);
|
|
else
|
|
ret = handle_signal32(&ksig, oldset, tsk);
|
|
} else {
|
|
ret = handle_rt_signal64(&ksig, oldset, tsk);
|
|
}
|
|
|
|
set_trap_norestart(tsk->thread.regs);
|
|
signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
|
|
}
|
|
|
|
void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
|
|
{
|
|
user_exit();
|
|
|
|
if (thread_info_flags & _TIF_UPROBE)
|
|
uprobe_notify_resume(regs);
|
|
|
|
if (thread_info_flags & _TIF_PATCH_PENDING)
|
|
klp_update_patch_state(current);
|
|
|
|
if (thread_info_flags & _TIF_SIGPENDING) {
|
|
BUG_ON(regs != current->thread.regs);
|
|
do_signal(current);
|
|
}
|
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
tracehook_notify_resume(regs);
|
|
rseq_handle_notify_resume(NULL, regs);
|
|
}
|
|
|
|
user_enter();
|
|
}
|
|
|
|
unsigned long get_tm_stackpointer(struct task_struct *tsk)
|
|
{
|
|
/* When in an active transaction that takes a signal, we need to be
|
|
* careful with the stack. It's possible that the stack has moved back
|
|
* up after the tbegin. The obvious case here is when the tbegin is
|
|
* called inside a function that returns before a tend. In this case,
|
|
* the stack is part of the checkpointed transactional memory state.
|
|
* If we write over this non transactionally or in suspend, we are in
|
|
* trouble because if we get a tm abort, the program counter and stack
|
|
* pointer will be back at the tbegin but our in memory stack won't be
|
|
* valid anymore.
|
|
*
|
|
* To avoid this, when taking a signal in an active transaction, we
|
|
* need to use the stack pointer from the checkpointed state, rather
|
|
* than the speculated state. This ensures that the signal context
|
|
* (written tm suspended) will be written below the stack required for
|
|
* the rollback. The transaction is aborted because of the treclaim,
|
|
* so any memory written between the tbegin and the signal will be
|
|
* rolled back anyway.
|
|
*
|
|
* For signals taken in non-TM or suspended mode, we use the
|
|
* normal/non-checkpointed stack pointer.
|
|
*/
|
|
|
|
unsigned long ret = tsk->thread.regs->gpr[1];
|
|
|
|
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
|
|
BUG_ON(tsk != current);
|
|
|
|
if (MSR_TM_ACTIVE(tsk->thread.regs->msr)) {
|
|
preempt_disable();
|
|
tm_reclaim_current(TM_CAUSE_SIGNAL);
|
|
if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr))
|
|
ret = tsk->thread.ckpt_regs.gpr[1];
|
|
|
|
/*
|
|
* If we treclaim, we must clear the current thread's TM bits
|
|
* before re-enabling preemption. Otherwise we might be
|
|
* preempted and have the live MSR[TS] changed behind our back
|
|
* (tm_recheckpoint_new_task() would recheckpoint). Besides, we
|
|
* enter the signal handler in non-transactional state.
|
|
*/
|
|
tsk->thread.regs->msr &= ~MSR_TS_MASK;
|
|
preempt_enable();
|
|
}
|
|
#endif
|
|
return ret;
|
|
}
|