cregit-Linux how code gets into the kernel

Release 4.7 arch/score/kernel/signal.c

/*
 * arch/score/kernel/signal.c
 *
 * Score Processor version.
 *
 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
 *  Chen Liqin <liqin.chen@sunplusct.com>
 *  Lennox Wu <lennox.wu@sunplusct.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/uaccess.h>
#include <linux/tracehook.h>

#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/ucontext.h>


struct rt_sigframe {
	
u32 rs_ass[4];		/* argument save space */
	
u32 rs_code[2];		/* signal trampoline */
	
struct siginfo rs_info;
	
struct ucontext rs_uc;
};


static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { int err = 0; unsigned long reg; reg = regs->cp0_epc; err |= __put_user(reg, &sc->sc_pc); err |= __put_user(regs->cp0_psr, &sc->sc_psr); err |= __put_user(regs->cp0_condition, &sc->sc_condition); #define save_gp_reg(i) { \ reg = regs->regs[i]; \ err |= __put_user(reg, &sc->sc_regs[i]); \ } while (0) save_gp_reg(0); save_gp_reg(1); save_gp_reg(2); save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6); save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10); save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14); save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18); save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22); save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26); save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); #undef save_gp_reg reg = regs->ceh; err |= __put_user(reg, &sc->sc_mdceh); reg = regs->cel; err |= __put_user(reg, &sc->sc_mdcel); err |= __put_user(regs->cp0_ecr, &sc->sc_ecr); err |= __put_user(regs->cp0_ema, &sc->sc_ema); return err; }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin29899.67%150.00%
arnd bergmannarnd bergmann10.33%150.00%
Total299100.00%2100.00%


static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { int err = 0; u32 reg; err |= __get_user(regs->cp0_epc, &sc->sc_pc); err |= __get_user(regs->cp0_condition, &sc->sc_condition); err |= __get_user(reg, &sc->sc_mdceh); regs->ceh = (int) reg; err |= __get_user(reg, &sc->sc_mdcel); regs->cel = (int) reg; err |= __get_user(reg, &sc->sc_psr); regs->cp0_psr = (int) reg; err |= __get_user(reg, &sc->sc_ecr); regs->cp0_ecr = (int) reg; err |= __get_user(reg, &sc->sc_ema); regs->cp0_ema = (int) reg; #define restore_gp_reg(i) do { \ err |= __get_user(reg, &sc->sc_regs[i]); \ regs->regs[i] = reg; \ } while (0) restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2); restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5); restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8); restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18); restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29); #undef restore_gp_reg return err; }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin32099.69%150.00%
arnd bergmannarnd bergmann10.31%150.00%
Total321100.00%2100.00%

/* * Determine which stack to use.. */
static 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->regs[0]; sp -= 32; /* This is the X/Open sanctioned signal stack switching. */ if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp))) sp = current->sas_ss_sp + current->sas_ss_size; return (void __user*)((sp - frame_size) & ~7); }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin8597.70%133.33%
arnd bergmannarnd bergmann22.30%266.67%
Total87100.00%3100.00%


asmlinkage long score_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe __user *frame; sigset_t set; int sig; /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; frame = (struct rt_sigframe __user *) regs->regs[0]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) goto badframe; set_current_blocked(&set); sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); if (sig < 0) goto badframe; else if (sig) force_sig(sig, current); if (restore_altstack(&frame->rs_uc.uc_stack)) goto badframe; regs->is_syscall = 0; __asm__ __volatile__( "mv\tr0, %0\n\t" "la\tr8, syscall_exit\n\t" "br\tr8\n\t" : : "r" (regs) : "r8"); badframe: force_sig(SIGSEGV, current); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin14084.34%112.50%
al viroal viro1911.45%450.00%
arnd bergmannarnd bergmann53.01%112.50%
matt flemingmatt fleming10.60%112.50%
andy lutomirskiandy lutomirski10.60%112.50%
Total166100.00%8100.00%


static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs, sigset_t *set) { struct rt_sigframe __user *frame; int err = 0; frame = get_sigframe(&ksig->ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return -EFAULT; /* * Set up the return code ... * * li v0, __NR_rt_sigreturn * syscall */ err |= __put_user(0x87788000 + __NR_rt_sigreturn*2, frame->rs_code + 0); err |= __put_user(0x80008002, frame->rs_code + 1); flush_cache_sigtramp((unsigned long) frame->rs_code); err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info); err |= __put_user(0, &frame->rs_uc.uc_flags); err |= __put_user(NULL, &frame->rs_uc.uc_link); err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[0]); err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); if (err) return -EFAULT; regs->regs[0] = (unsigned long) frame; regs->regs[3] = (unsigned long) frame->rs_code; regs->regs[4] = ksig->sig; regs->regs[5] = (unsigned long) &frame->rs_info; regs->regs[6] = (unsigned long) &frame->rs_uc; regs->regs[29] = (unsigned long) ksig->ka.sa.sa_handler; regs->cp0_epc = (unsigned long) ksig->ka.sa.sa_handler; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin29490.74%116.67%
richard weinbergerrichard weinberger257.72%116.67%
arnd bergmannarnd bergmann30.93%350.00%
al viroal viro20.62%116.67%
Total324100.00%6100.00%


static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) { int ret; if (regs->is_syscall) { switch (regs->regs[4]) { case ERESTART_RESTARTBLOCK: case ERESTARTNOHAND: regs->regs[4] = EINTR; break; case ERESTARTSYS: if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { regs->regs[4] = EINTR; break; } case ERESTARTNOINTR: regs->regs[4] = regs->orig_r4; regs->regs[7] = regs->orig_r7; regs->cp0_epc -= 8; } regs->is_syscall = 0; } /* * Set up the stack frame */ ret = setup_rt_frame(ksig, regs, sigmask_to_save()); signal_setup_done(ret, ksig, 0); }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin12184.62%116.67%
richard weinbergerrichard weinberger1510.49%116.67%
al viroal viro64.20%350.00%
arnd bergmannarnd bergmann10.70%116.67%
Total143100.00%6100.00%


static void do_signal(struct pt_regs *regs) { struct ksignal ksig; /* * 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; if (get_signal(&ksig)) { /* Actually deliver the signal. */ handle_signal(&ksig, regs); return; } if (regs->is_syscall) { if (regs->regs[4] == ERESTARTNOHAND || regs->regs[4] == ERESTARTSYS || regs->regs[4] == ERESTARTNOINTR) { regs->regs[4] = regs->orig_r4; regs->regs[7] = regs->orig_r7; regs->cp0_epc -= 8; } if (regs->regs[4] == ERESTART_RESTARTBLOCK) { regs->regs[27] = __NR_restart_syscall; regs->regs[4] = regs->orig_r4; regs->regs[7] = regs->orig_r7; regs->cp0_epc -= 8; } regs->is_syscall = 0; /* Don't deal with this again. */ } /* * If there's no signal to deliver, we just put the saved sigmask * back */ restore_saved_sigmask(); }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin16394.22%125.00%
richard weinbergerrichard weinberger74.05%125.00%
al viroal viro21.16%125.00%
arnd bergmannarnd bergmann10.58%125.00%
Total173100.00%4100.00%

/* * notification of userspace execution resumption * - triggered by the TIF_WORK_MASK flags */
asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) { /* 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); } }

Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin3062.50%150.00%
al viroal viro1837.50%150.00%
Total48100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
chen liqinchen liqin150392.89%211.11%
al viroal viro503.09%950.00%
richard weinbergerrichard weinberger472.90%15.56%
arnd bergmannarnd bergmann160.99%422.22%
matt flemingmatt fleming10.06%15.56%
andy lutomirskiandy lutomirski10.06%15.56%
Total1618100.00%18100.00%
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