cregit-Linux how code gets into the kernel

Release 4.14 arch/m32r/kernel/signal.c

Directory: arch/m32r/kernel
// SPDX-License-Identifier: GPL-2.0
/*
 *  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/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>


#define DEBUG_SIG 0

/*
 * 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->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; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata19799.49%266.67%
Andrew Lutomirski10.51%133.33%
Total198100.00%3100.00%


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; set_current_blocked(&set); if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result)) goto badframe; if (restore_altstack(&frame->uc.uc_stack)) goto badframe; return result; badframe: force_sig(SIGSEGV, current); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata15597.48%350.00%
Jesper Juhl21.26%116.67%
Al Viro10.63%116.67%
Matt Fleming10.63%116.67%
Total159100.00%6100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata183100.00%3100.00%
Total183100.00%3100.00%

/* * Determine which stack to use.. */
static inline void __user * get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size) { return (void __user *)((sigsp(sp, ksig) - frame_size) & -8ul); }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata3683.72%266.67%
Richard Weinberger716.28%133.33%
Total43100.00%3100.00%


static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { struct rt_sigframe __user *frame; int err = 0; int sig = ksig->sig; frame = get_sigframe(ksig, regs->spu, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return -EFAULT; err |= __put_user(sig, &frame->sig); if (err) return -EFAULT; err |= __put_user(&frame->info, &frame->pinfo); err |= __put_user(&frame->uc, &frame->puc); err |= copy_siginfo_to_user(&frame->info, &ksig->info); if (err) return -EFAULT; /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __save_altstack(&frame->uc.uc_stack, regs->spu); err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) return -EFAULT; /* Set up to return from userspace. */ regs->lr = (unsigned long)ksig->ka.sa.sa_restorer; /* Set up registers for signal handler */ regs->spu = (unsigned long)frame; regs->r0 = sig; /* Arg for signal handler */ regs->r1 = (unsigned long)&frame->info; regs->r2 = (unsigned long)&frame->uc; regs->bpc = (unsigned long)ksig->ka.sa.sa_handler; #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%p\n", current->comm, current->pid, frame, regs->pc); #endif return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata30588.15%120.00%
Richard Weinberger3510.12%240.00%
Al Viro61.73%240.00%
Total346100.00%5100.00%


static int prev_insn(struct pt_regs *regs) { u16 inst; if (get_user(inst, (u16 __user *)(regs->bpc - 2))) return -EFAULT; if ((inst & 0xfff0) == 0x10f0) /* trap ? */ regs->bpc -= 2; else regs->bpc -= 4; regs->syscall_nr = -1; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro72100.00%1100.00%
Total72100.00%1100.00%

/* * OK, we're invoking a handler */
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) { int ret; /* 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 (!(ksig->ka.sa.sa_flags & SA_RESTART)) { regs->r0 = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->r0 = regs->orig_r0; if (prev_insn(regs) < 0) return; } } /* Set up the stack frame */ ret = setup_rt_frame(ksig, sigmask_to_save(), regs); signal_setup_done(ret, ksig, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata10077.52%222.22%
Richard Weinberger1511.63%111.11%
Al Viro1310.08%555.56%
Geert Uytterhoeven10.78%111.11%
Total129100.00%9100.00%

/* * 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 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)) { /* 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(&ksig, regs); return; } /* 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; prev_insn(regs); } else if (regs->r0 == -ERESTART_RESTARTBLOCK){ regs->r0 = regs->orig_r0; regs->r7 = __NR_restart_syscall; prev_insn(regs); } } restore_saved_sigmask(); }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata10278.46%222.22%
Al Viro2015.38%555.56%
Richard Weinberger75.38%111.11%
Simon Arlott10.77%111.11%
Total130100.00%9100.00%

/* * 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); } }

Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata3767.27%150.00%
David Howells1832.73%150.00%
Total55100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Hirokazu Takata119085.18%518.52%
Al Viro1148.16%1037.04%
Richard Weinberger644.58%311.11%
David Howells211.50%27.41%
Jesper Juhl20.14%13.70%
Matt Fleming10.07%13.70%
Greg Kroah-Hartman10.07%13.70%
Linus Torvalds10.07%13.70%
Andrew Lutomirski10.07%13.70%
Geert Uytterhoeven10.07%13.70%
Simon Arlott10.07%13.70%
Total1397100.00%27100.00%
Directory: arch/m32r/kernel
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