[Feature][T106]ZXW P56U09 code
Only Configure: Yes
Affected branch: master
Affected module: unknow
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: No
Doc Update: No
Change-Id: I3cbd8b420271eb20c2b40ebe5c78f83059cd42f3
diff --git a/ap/os/linux/linux-3.4.x/arch/arm/kernel/signal.c b/ap/os/linux/linux-3.4.x/arch/arm/kernel/signal.c
new file mode 100644
index 0000000..51532cb
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/arch/arm/kernel/signal.c
@@ -0,0 +1,747 @@
+/*
+ * linux/arch/arm/kernel/signal.c
+ *
+ * Copyright (C) 1995-2009 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/personality.h>
+#include <linux/freezer.h>
+#include <linux/uaccess.h>
+#include <linux/tracehook.h>
+
+#include <asm/elf.h>
+#include <asm/cacheflush.h>
+#include <asm/ucontext.h>
+#include <asm/unistd.h>
+#include <asm/vfp.h>
+
+#include "signal.h"
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+/*
+ * For ARM syscalls, we encode the syscall number into the instruction.
+ */
+#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
+#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
+#define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE)
+
+/*
+ * With EABI, the syscall number has to be loaded into r7.
+ */
+#define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
+#define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
+
+/*
+ * For Thumb syscalls, we pass the syscall number via r7. We therefore
+ * need two 16-bit instructions.
+ */
+#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
+#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
+
+const unsigned long sigreturn_codes[7] = {
+ MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
+ MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
+};
+
+/*
+ * Either we support OABI only, or we have EABI with the OABI
+ * compat layer enabled. In the later case we don't know if
+ * user space is EABI or not, and if not we must not clobber r7.
+ * Always using the OABI syscall solves that issue and works for
+ * all those cases.
+ */
+const unsigned long syscall_restart_code[2] = {
+ SWI_SYS_RESTART, /* swi __NR_restart_syscall */
+ 0xe49df004, /* ldr pc, [sp], #4 */
+};
+
+/*
+ * atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
+{
+ sigset_t blocked;
+
+ current->saved_sigmask = current->blocked;
+
+ mask &= _BLOCKABLE;
+ siginitset(&blocked, mask);
+ set_current_blocked(&blocked);
+
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+ set_restore_sigmask();
+ return -ERESTARTNOHAND;
+}
+
+asmlinkage int
+sys_sigaction(int sig, const struct old_sigaction __user *act,
+ struct old_sigaction __user *oact)
+{
+ struct k_sigaction new_ka, old_ka;
+ int ret;
+
+ if (act) {
+ old_sigset_t mask;
+ if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+ __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+ __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+ return -EFAULT;
+ __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+ __get_user(mask, &act->sa_mask);
+ siginitset(&new_ka.sa.sa_mask, mask);
+ }
+
+ ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+ if (!ret && oact) {
+ if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+ __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+ __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+ return -EFAULT;
+ __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+ __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_CRUNCH
+static int preserve_crunch_context(struct crunch_sigframe __user *frame)
+{
+ char kbuf[sizeof(*frame) + 8];
+ struct crunch_sigframe *kframe;
+
+ /* the crunch context must be 64 bit aligned */
+ kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
+ kframe->magic = CRUNCH_MAGIC;
+ kframe->size = CRUNCH_STORAGE_SIZE;
+ crunch_task_copy(current_thread_info(), &kframe->storage);
+ return __copy_to_user(frame, kframe, sizeof(*frame));
+}
+
+static int restore_crunch_context(struct crunch_sigframe __user *frame)
+{
+ char kbuf[sizeof(*frame) + 8];
+ struct crunch_sigframe *kframe;
+
+ /* the crunch context must be 64 bit aligned */
+ kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
+ if (__copy_from_user(kframe, frame, sizeof(*frame)))
+ return -1;
+ if (kframe->magic != CRUNCH_MAGIC ||
+ kframe->size != CRUNCH_STORAGE_SIZE)
+ return -1;
+ crunch_task_restore(current_thread_info(), &kframe->storage);
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_IWMMXT
+
+static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
+{
+ char kbuf[sizeof(*frame) + 8];
+ struct iwmmxt_sigframe *kframe;
+
+ /* the iWMMXt context must be 64 bit aligned */
+ kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
+ kframe->magic = IWMMXT_MAGIC;
+ kframe->size = IWMMXT_STORAGE_SIZE;
+ iwmmxt_task_copy(current_thread_info(), &kframe->storage);
+ return __copy_to_user(frame, kframe, sizeof(*frame));
+}
+
+static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
+{
+ char kbuf[sizeof(*frame) + 8];
+ struct iwmmxt_sigframe *kframe;
+
+ /* the iWMMXt context must be 64 bit aligned */
+ kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
+ if (__copy_from_user(kframe, frame, sizeof(*frame)))
+ return -1;
+ if (kframe->magic != IWMMXT_MAGIC ||
+ kframe->size != IWMMXT_STORAGE_SIZE)
+ return -1;
+ iwmmxt_task_restore(current_thread_info(), &kframe->storage);
+ return 0;
+}
+
+#endif
+
+#ifdef CONFIG_VFP
+
+static int preserve_vfp_context(struct vfp_sigframe __user *frame)
+{
+ const unsigned long magic = VFP_MAGIC;
+ const unsigned long size = VFP_STORAGE_SIZE;
+ int err = 0;
+
+ __put_user_error(magic, &frame->magic, err);
+ __put_user_error(size, &frame->size, err);
+
+ if (err)
+ return -EFAULT;
+
+ return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);
+}
+
+static int restore_vfp_context(struct vfp_sigframe __user *frame)
+{
+ unsigned long magic;
+ unsigned long size;
+ int err = 0;
+
+ __get_user_error(magic, &frame->magic, err);
+ __get_user_error(size, &frame->size, err);
+
+ if (err)
+ return -EFAULT;
+ if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
+ return -EINVAL;
+
+ return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc);
+}
+
+#endif
+
+/*
+ * Do a signal return; undo the signal stack. These are aligned to 64-bit.
+ */
+struct sigframe {
+ struct ucontext uc;
+ unsigned long retcode[2];
+};
+
+struct rt_sigframe {
+ struct siginfo info;
+ struct sigframe sig;
+};
+
+static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
+{
+ struct aux_sigframe __user *aux;
+ sigset_t set;
+ int err;
+
+ err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
+ if (err == 0) {
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ set_current_blocked(&set);
+ }
+
+ __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
+ __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
+ __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
+ __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
+ __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
+ __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
+ __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
+ __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
+ __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
+ __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
+ __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
+ __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
+ __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
+ __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
+ __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
+ __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
+ __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+ err |= !valid_user_regs(regs);
+
+ aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
+#ifdef CONFIG_CRUNCH
+ if (err == 0)
+ err |= restore_crunch_context(&aux->crunch);
+#endif
+#ifdef CONFIG_IWMMXT
+ if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
+ err |= restore_iwmmxt_context(&aux->iwmmxt);
+#endif
+#ifdef CONFIG_VFP
+ if (err == 0)
+ err |= restore_vfp_context(&aux->vfp);
+#endif
+
+ return err;
+}
+
+asmlinkage int sys_sigreturn(struct pt_regs *regs)
+{
+ struct sigframe __user *frame;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Since we stacked the signal on a 64-bit boundary,
+ * then 'sp' should be word aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (regs->ARM_sp & 7)
+ goto badframe;
+
+ frame = (struct sigframe __user *)regs->ARM_sp;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+ goto badframe;
+
+ if (restore_sigframe(regs, frame))
+ goto badframe;
+
+ return regs->ARM_r0;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Since we stacked the signal on a 64-bit boundary,
+ * then 'sp' should be word aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (regs->ARM_sp & 7)
+ goto badframe;
+
+ frame = (struct rt_sigframe __user *)regs->ARM_sp;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+ goto badframe;
+
+ if (restore_sigframe(regs, &frame->sig))
+ goto badframe;
+
+ if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
+ goto badframe;
+
+ return regs->ARM_r0;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+static int
+setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
+{
+ struct aux_sigframe __user *aux;
+ int err = 0;
+
+ __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
+ __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
+ __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
+ __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
+ __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
+ __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
+ __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
+ __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
+ __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
+ __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
+ __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
+ __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
+ __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
+ __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
+ __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
+ __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
+ __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+ __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
+ __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
+ __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
+ __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
+
+ err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
+
+ aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
+#ifdef CONFIG_CRUNCH
+ if (err == 0)
+ err |= preserve_crunch_context(&aux->crunch);
+#endif
+#ifdef CONFIG_IWMMXT
+ if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
+ err |= preserve_iwmmxt_context(&aux->iwmmxt);
+#endif
+#ifdef CONFIG_VFP
+ if (err == 0)
+ err |= preserve_vfp_context(&aux->vfp);
+#endif
+ __put_user_error(0, &aux->end_magic, err);
+
+ return err;
+}
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
+{
+ unsigned long sp = regs->ARM_sp;
+ void __user *frame;
+
+ /*
+ * This is the X/Open sanctioned signal stack switching.
+ */
+ if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
+ sp = current->sas_ss_sp + current->sas_ss_size;
+
+ /*
+ * ATPCS B01 mandates 8-byte alignment
+ */
+ frame = (void __user *)((sp - framesize) & ~7);
+
+ /*
+ * Check that we can actually write to the signal frame.
+ */
+ if (!access_ok(VERIFY_WRITE, frame, framesize))
+ frame = NULL;
+
+ return frame;
+}
+
+static int
+setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+ unsigned long __user *rc, void __user *frame, int usig)
+{
+ unsigned long handler = (unsigned long)ka->sa.sa_handler;
+ unsigned long retcode;
+ int thumb = 0;
+ unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
+
+ cpsr |= PSR_ENDSTATE;
+
+ /*
+ * Maybe we need to deliver a 32-bit signal to a 26-bit task.
+ */
+ if (ka->sa.sa_flags & SA_THIRTYTWO)
+ cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
+
+#ifdef CONFIG_ARM_THUMB
+ if (elf_hwcap & HWCAP_THUMB) {
+ /*
+ * The LSB of the handler determines if we're going to
+ * be using THUMB or ARM mode for this signal handler.
+ */
+ thumb = handler & 1;
+
+ if (thumb) {
+ cpsr |= PSR_T_BIT;
+#if __LINUX_ARM_ARCH__ >= 7
+ /* clear the If-Then Thumb-2 execution state */
+ cpsr &= ~PSR_IT_MASK;
+#endif
+ } else
+ cpsr &= ~PSR_T_BIT;
+ }
+#endif
+
+ if (ka->sa.sa_flags & SA_RESTORER) {
+ retcode = (unsigned long)ka->sa.sa_restorer;
+ } else {
+ unsigned int idx = thumb << 1;
+
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ idx += 3;
+
+ if (__put_user(sigreturn_codes[idx], rc) ||
+ __put_user(sigreturn_codes[idx+1], rc+1))
+ return 1;
+
+ if (cpsr & MODE32_BIT) {
+ /*
+ * 32-bit code can use the new high-page
+ * signal return code support.
+ */
+ retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
+ } else {
+ /*
+ * Ensure that the instruction cache sees
+ * the return code written onto the stack.
+ */
+ flush_icache_range((unsigned long)rc,
+ (unsigned long)(rc + 2));
+
+ retcode = ((unsigned long)rc) + thumb;
+ }
+ }
+
+ regs->ARM_r0 = usig;
+ regs->ARM_sp = (unsigned long)frame;
+ regs->ARM_lr = retcode;
+ regs->ARM_pc = handler;
+ regs->ARM_cpsr = cpsr;
+
+ return 0;
+}
+
+static int
+setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
+{
+ struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
+ int err = 0;
+
+ if (!frame)
+ return 1;
+
+ /*
+ * Set uc.uc_flags to a value which sc.trap_no would never have.
+ */
+ __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
+
+ err |= setup_sigframe(frame, regs, set);
+ if (err == 0)
+ err = setup_return(regs, ka, frame->retcode, frame, usig);
+
+ return err;
+}
+
+static int
+setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
+ stack_t stack;
+ int err = 0;
+
+ if (!frame)
+ return 1;
+
+ err |= copy_siginfo_to_user(&frame->info, info);
+
+ __put_user_error(0, &frame->sig.uc.uc_flags, err);
+ __put_user_error(NULL, &frame->sig.uc.uc_link, err);
+
+ memset(&stack, 0, sizeof(stack));
+ stack.ss_sp = (void __user *)current->sas_ss_sp;
+ stack.ss_flags = sas_ss_flags(regs->ARM_sp);
+ stack.ss_size = current->sas_ss_size;
+ err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
+
+ err |= setup_sigframe(&frame->sig, regs, set);
+ if (err == 0)
+ err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
+
+ if (err == 0) {
+ /*
+ * For realtime signals we must also set the second and third
+ * arguments for the signal handler.
+ * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
+ */
+ regs->ARM_r1 = (unsigned long)&frame->info;
+ regs->ARM_r2 = (unsigned long)&frame->sig.uc;
+ }
+
+ return err;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static int
+handle_signal(unsigned long sig, struct k_sigaction *ka,
+ siginfo_t *info, sigset_t *oldset,
+ struct pt_regs * regs)
+{
+ struct thread_info *thread = current_thread_info();
+ struct task_struct *tsk = current;
+ int usig = sig;
+ int ret;
+
+ /*
+ * translate the signal
+ */
+ if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
+ usig = thread->exec_domain->signal_invmap[usig];
+
+ /*
+ * Set up the stack frame
+ */
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ ret = setup_rt_frame(usig, ka, info, oldset, regs);
+ else
+ ret = setup_frame(usig, ka, oldset, regs);
+
+ /*
+ * Check that the resulting registers are actually sane.
+ */
+ ret |= !valid_user_regs(regs);
+
+ if (ret != 0) {
+ force_sigsegv(sig, tsk);
+ return ret;
+ }
+
+ /*
+ * Block the signal if we were successful.
+ */
+ block_sigmask(ka, sig);
+
+ return 0;
+}
+
+/*
+ * 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.
+ */
+static void do_signal(struct pt_regs *regs, int syscall)
+{
+ unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
+ struct k_sigaction ka;
+ siginfo_t info;
+ int signr;
+
+ /*
+ * 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;
+
+ local_irq_enable();
+ preempt_check_resched();
+
+ /*
+ * If we were from a system call, check for system call restarting...
+ */
+ if (syscall) {
+ continue_addr = regs->ARM_pc;
+ restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
+ retval = regs->ARM_r0;
+
+ /*
+ * Prepare for system call restart. We do this here so that a
+ * debugger will see the already changed PSW.
+ */
+ switch (retval) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ regs->ARM_r0 = regs->ARM_ORIG_r0;
+ regs->ARM_pc = restart_addr;
+ break;
+ case -ERESTART_RESTARTBLOCK:
+ regs->ARM_r0 = -EINTR;
+ break;
+ }
+ }
+#ifdef CONFIG_FREEZER
+ if (try_to_freeze_nowarn())
+#else
+ if (try_to_freeze())
+#endif
+ goto no_signal;
+
+ /*
+ * Get the signal to deliver. When running under ptrace, at this
+ * point the debugger may change all our registers ...
+ */
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+ if (signr > 0) {
+ sigset_t *oldset;
+
+ /*
+ * Depending on the signal settings we may need to revert the
+ * decision to restart the system call. But skip this if a
+ * debugger has chosen to restart at a different PC.
+ */
+ if (regs->ARM_pc == restart_addr) {
+ if (retval == -ERESTARTNOHAND
+ || (retval == -ERESTARTSYS
+ && !(ka.sa.sa_flags & SA_RESTART))) {
+ regs->ARM_r0 = -EINTR;
+ regs->ARM_pc = continue_addr;
+ }
+ }
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = ¤t->saved_sigmask;
+ else
+ oldset = ¤t->blocked;
+ if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
+ /*
+ * A signal was successfully delivered; the saved
+ * sigmask will have been stored in the signal frame,
+ * and will be restored by sigreturn, so we can simply
+ * clear the TIF_RESTORE_SIGMASK flag.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ }
+ return;
+ }
+
+ no_signal:
+ if (syscall) {
+ /*
+ * Handle restarting a different system call. As above,
+ * if a debugger has chosen to restart at a different PC,
+ * ignore the restart.
+ */
+ if (retval == -ERESTART_RESTARTBLOCK
+ && regs->ARM_pc == continue_addr) {
+ if (thumb_mode(regs)) {
+ regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
+ regs->ARM_pc -= 2;
+ } else {
+#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
+ regs->ARM_r7 = __NR_restart_syscall;
+ regs->ARM_pc -= 4;
+#else
+ u32 __user *usp;
+
+ regs->ARM_sp -= 4;
+ usp = (u32 __user *)regs->ARM_sp;
+
+ if (put_user(regs->ARM_pc, usp) == 0) {
+ regs->ARM_pc = KERN_RESTART_CODE;
+ } else {
+ regs->ARM_sp += 4;
+ force_sigsegv(0, current);
+ }
+#endif
+ }
+ }
+
+ /* If there's no signal to deliver, we just put the saved sigmask
+ * back.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
+ }
+ }
+}
+
+asmlinkage void
+do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+{
+ if (thread_flags & _TIF_SIGPENDING)
+ do_signal(regs, syscall);
+
+ if (thread_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ if (current->replacement_session_keyring)
+ key_replace_session_keyring();
+ }
+}