signal32.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * signal32.c: Support 32bit signal syscalls.
 *
 * Copyright (C) 2001 IBM
 * Copyright (C) 1997,1998 Jakub Jelinek ([e-mail])
 * Copyright (C) 1997 David S. Miller ([e-mail])
 *
 * These routines maintain argument size conversion between 32bit and 64bit
 * environment.
 *
 *      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.
 */

#include <asm/ptrace.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h> 
#include <linux/mm.h> 
#include <linux/file.h> 
#include <linux/signal.h>
#include <linux/utime.h>
#include <linux/resource.h>
#include <linux/times.h>
#include <linux/utsname.h>
#include <linux/timex.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <linux/nfs_fs.h>
#include <linux/smb_fs.h>
#include <linux/smb_mount.h>
#include <linux/ncp_fs.h>
#include <linux/quota.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/personality.h>
#include <linux/stat.h>
#include <linux/filter.h>
#include <asm/types.h>
#include <asm/ipc.h>
#include <asm/uaccess.h>
#include <linux/elf.h>
#include <asm/ppc32.h>
#include <asm/ppcdebug.h>
#include <asm/unistd.h>
#include <asm/ucontext.h>

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
/* 
 * These are the flags in the MSR that the user is allowed to change
 * by modifying the saved value of the MSR on the stack.  SE and BE
 * should not be in this list since gdb may want to change these.  I.e,
 * you should be able to step out of a signal handler to see what
 * instruction executes next after the signal handler completes.
 * Alternately, if you stepped into a signal handler, you should be
 * able to continue 'til the next breakpoint from within the signal
 * handler, even if the handler returns.
 */
#define MSR_USERCHANGE	(MSR_FE0 | MSR_FE1)

struct timespec32 {
	s32    tv_sec;
	s32    tv_nsec;
};

struct sigregs32 {
    /***********************************************************************/
    /* the gp_regs array is 32 bit representation of the pt_regs structure */
    /*  that was stored on the kernle stack during the system call that    */
    /*  was interrupted for the signal.                                    */
    /*                                                                     */
    /* Note that the entire pt_regs regs structure will fit in the gp_regs */
    /*   structure because the ELF_NREG value is 48 for PPC and the pt_regs*/
    /*   structure contains 44 registers                                   */
    /*                                                                     */ 
    /***********************************************************************/ 
	elf_gregset_t32	gp_regs;
	double		fp_regs[ELF_NFPREG];
	unsigned int	tramp[2];
	/* Programs using the rs6000/xcoff abi can save up to 19 gp regs
	   and 18 fp regs below sp before decrementing it. */
	int		abigap[56];
};


struct rt_sigframe_32 {
	/* Unused space at start of frame to allow for storing of stack pointers */
	unsigned long _unused;
	/* This is a 32 bit pointer in user address space 
	 *     it is a pointer to the siginfo stucture in the rt stack frame 
	 */
	u32 pinfo;
	/* This is a 32 bit pointer in user address space */
	/*     it is a pointer to the user context in the rt stack frame  */
	u32 puc;
	struct siginfo32  info;
	struct ucontext32 uc;
};





extern asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru);


/****************************************************************************/
/*  Start of nonRT signal support                                           */
/*                                                                          */
/*     sigset_t is 32 bits for non-rt signals                               */
/*                                                                          */
/*  System Calls                                                            */
/*       sigaction                sys32_sigaction                           */
/*       sigpending               sys32_sigpending                          */
/*       sigprocmask              sys32_sigprocmask                         */
/*       sigreturn                sys32_sigreturn                           */
/*                                                                          */
/*  Note sigsuspend has no special 32 bit routine - uses the 64 bit routine */ 
/*                                                                          */
/*  Other routines                                                          */
/*        setup_frame32                                                     */
/*                                                                          */
/****************************************************************************/


asmlinkage long sys32_sigaction(int sig, struct old_sigaction32 *act, struct old_sigaction32 *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;
	
	PPCDBG(PPCDBG_SYS32, "sys32_sigaction - entered - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);

	if (sig < 0)
	{
		sig = -sig;
	}

	if (act)
	{
		old_sigset_t32 mask;

		ret = get_user((long)new_ka.sa.sa_handler, &act->sa_handler);
		ret |= __get_user((long)new_ka.sa.sa_restorer, &act->sa_restorer);
		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		ret |= __get_user(mask, &act->sa_mask);
		if (ret)
			return ret;
		PPCDBG(PPCDBG_SIGNAL, "sys32_sigaction flags =%lx  \n", new_ka.sa.sa_flags);

		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact)
	{
		ret = put_user((long)old_ka.sa.sa_handler, &oact->sa_handler);
		ret |= __put_user((long)old_ka.sa.sa_restorer, &oact->sa_restorer);
		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		ret |= __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	}

	
	PPCDBG(PPCDBG_SYS32, "sys32_sigaction - exited - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);

	return ret;
}




extern asmlinkage long sys_sigpending(old_sigset_t *set);

asmlinkage long sys32_sigpending(old_sigset_t32 *set)
{
	old_sigset_t s;
	int ret;
	mm_segment_t old_fs = get_fs();
	
	PPCDBG(PPCDBG_SYS32, "sys32_sigpending - entered - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);
		
	set_fs (KERNEL_DS);
	ret = sys_sigpending(&s);
	set_fs (old_fs);
	if (put_user (s, set)) return -EFAULT;
	
	PPCDBG(PPCDBG_SYS32, "sys32_sigpending - exited - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);

	return ret;
}




extern asmlinkage long sys_sigprocmask(int how, old_sigset_t *set, old_sigset_t *oset);

/* Note: it is necessary to treat how as an unsigned int, 
 * with the corresponding cast to a signed int to insure that the 
 * proper conversion (sign extension) between the register representation of a signed int (msr in 32-bit mode)
 * and the register representation of a signed int (msr in 64-bit mode) is performed.
 */
asmlinkage long sys32_sigprocmask(u32 how, old_sigset_t32 *set, old_sigset_t32 *oset)
{
	old_sigset_t s;
	int ret;
	mm_segment_t old_fs = get_fs();
	
	PPCDBG(PPCDBG_SYS32, "sys32_sigprocmask - entered - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);
	
	if (set && get_user (s, set)) return -EFAULT;
	set_fs (KERNEL_DS);
	ret = sys_sigprocmask((int)how, set ? &s : NULL, oset ? &s : NULL);
	set_fs (old_fs);
	if (ret) return ret;
	if (oset && put_user (s, oset)) return -EFAULT;
	
	PPCDBG(PPCDBG_SYS32, "sys32_sigprocmask - exited - pid=%ld current=%lx comm=%s\n", current->pid, current, current->comm);

	return 0;
}



/*
 * When we have signals to deliver, we set up on the
 * user stack, going down from the original stack pointer:
 *	a sigregs struct
 *	one or more sigcontext structs
 *	a gap of __SIGNAL_FRAMESIZE32 bytes
 *
 * Each of these things must be a multiple of 16 bytes in size.
 *
*/


/*
 * Do a signal return; undo the signal stack.
 */
long sys32_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
		     unsigned long r6, unsigned long r7, unsigned long r8,
		     struct pt_regs *regs)
{
	struct sigcontext32_struct *sc, sigctx;
	struct sigregs32 *sr;
	int ret;
	elf_gregset_t32 saved_regs;  /* an array of ELF_NGREG unsigned ints (32 bits) */
	sigset_t set;
	unsigned int prevsp;

	PPCDBG(PPCDBG_SIGNAL, "sys32_sigreturn - entered - pid=%ld current=%lx comm=%s \n", current->pid, current, current->comm);

	sc = (struct sigcontext32_struct *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32);
	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
		goto badframe;

	/* Note that PPC32 puts the upper 32 bits of the sigmask in the  */
	/*   unused part of the signal stackframe                        */
	set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3])<< 32);
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sigmask_lock);
	current->blocked = set;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	sc++;			/* Look at next sigcontext */
	/* If the next sigcontext is actually the sigregs (frame)  */
	/*   - then no more sigcontexts on the user stack          */  
	if (sc == (struct sigcontext32_struct*)(u64)sigctx.regs)
	{
		/* Last stacked signal - restore registers */
		sr = (struct sigregs32*)(u64)sigctx.regs;
		if (regs->msr & MSR_FP )
			giveup_fpu(current);
		/* copy the 32 bit register values off the user stack */
		/*   into the 32 bit register area                    */
		if (copy_from_user(saved_regs, &sr->gp_regs,sizeof(sr->gp_regs)))
			goto badframe;
		/**********************************************************************/
		/* The saved reg structure in the frame is an elf_grepset_t32, it is  */
		/*   a 32 bit register save of the registers in the pt_regs structure */
		/*   that was stored on the kernel stack during the system call       */
		/*   when the system call was interrupted for the signal. Only 32 bits*/
		/*   are saved because the sigcontext contains a pointer to the regs  */
		/*   and the sig context address is passed as a pointer to the signal */
		/*   handler.                                                         */
		/*                                                                    */
		/* The entries in the elf_grepset have the same index as the elements */
		/*   in the pt_regs structure.                                        */
		/*                                                                    */
		/**********************************************************************/

		saved_regs[PT_MSR] = (regs->msr & ~MSR_USERCHANGE)
			| (saved_regs[PT_MSR] & MSR_USERCHANGE);
		regs->gpr[0] = (u64)(saved_regs[0]) & 0xFFFFFFFF;
		regs->gpr[1] = (u64)(saved_regs[1]) & 0xFFFFFFFF;
		/**********************************************************************/
		/* Register 2 is the kernel toc - should be reset on any calls into   */
		/*  the kernel                                                        */
		/**********************************************************************/
		regs->gpr[2] = (u64)(saved_regs[2]) & 0xFFFFFFFF;

		regs->gpr[3] = (u64)(saved_regs[3]) & 0xFFFFFFFF;
		regs->gpr[4] = (u64)(saved_regs[4]) & 0xFFFFFFFF;
		regs->gpr[5] = (u64)(saved_regs[5]) & 0xFFFFFFFF;
		regs->gpr[6] = (u64)(saved_regs[6]) & 0xFFFFFFFF;
		regs->gpr[7] = (u64)(saved_regs[7]) & 0xFFFFFFFF;
		regs->gpr[8] = (u64)(saved_regs[8]) & 0xFFFFFFFF;
		regs->gpr[9] = (u64)(saved_regs[9]) & 0xFFFFFFFF;
		regs->gpr[10] = (u64)(saved_regs[10]) & 0xFFFFFFFF;
		regs->gpr[11] = (u64)(saved_regs[11]) & 0xFFFFFFFF;
		regs->gpr[12] = (u64)(saved_regs[12]) & 0xFFFFFFFF;
		regs->gpr[13] = (u64)(saved_regs[13]) & 0xFFFFFFFF;
		regs->gpr[14] = (u64)(saved_regs[14]) & 0xFFFFFFFF;
		regs->gpr[15] = (u64)(saved_regs[15]) & 0xFFFFFFFF;
		regs->gpr[16] = (u64)(saved_regs[16]) & 0xFFFFFFFF;
		regs->gpr[17] = (u64)(saved_regs[17]) & 0xFFFFFFFF;
		regs->gpr[18] = (u64)(saved_regs[18]) & 0xFFFFFFFF;
		regs->gpr[19] = (u64)(saved_regs[19]) & 0xFFFFFFFF;
		regs->gpr[20] = (u64)(saved_regs[20]) & 0xFFFFFFFF;
		regs->gpr[21] = (u64)(saved_regs[21]) & 0xFFFFFFFF;
		regs->gpr[22] = (u64)(saved_regs[22]) & 0xFFFFFFFF;
		regs->gpr[23] = (u64)(saved_regs[23]) & 0xFFFFFFFF;
		regs->gpr[24] = (u64)(saved_regs[24]) & 0xFFFFFFFF;
		regs->gpr[25] = (u64)(saved_regs[25]) & 0xFFFFFFFF;
		regs->gpr[26] = (u64)(saved_regs[26]) & 0xFFFFFFFF;
		regs->gpr[27] = (u64)(saved_regs[27]) & 0xFFFFFFFF;
		regs->gpr[28] = (u64)(saved_regs[28]) & 0xFFFFFFFF;
		regs->gpr[29] = (u64)(saved_regs[29]) & 0xFFFFFFFF;
		regs->gpr[30] = (u64)(saved_regs[30]) & 0xFFFFFFFF;
		regs->gpr[31] = (u64)(saved_regs[31]) & 0xFFFFFFFF;
		/****************************************************/
		/*  restore the non gpr registers                   */
		/****************************************************/
		regs->msr = (u64)(saved_regs[PT_MSR]) & 0xFFFFFFFF;
		/* Insure that the interrupt mode is 64 bit, during 32 bit execution.
		 * (This is necessary because we only saved lower 32 bits of msr.)
		 */
		regs->msr = regs->msr | MSR_ISF;  /* When this thread is interrupted it should run in 64 bit mode. */

		regs->nip = (u64)(saved_regs[PT_NIP]) & 0xFFFFFFFF;
		regs->orig_gpr3 = (u64)(saved_regs[PT_ORIG_R3]) & 0xFFFFFFFF; 
		regs->ctr = (u64)(saved_regs[PT_CTR]) & 0xFFFFFFFF; 
		regs->link = (u64)(saved_regs[PT_LNK]) & 0xFFFFFFFF; 
		regs->xer = (u64)(saved_regs[PT_XER]) & 0xFFFFFFFF; 
		regs->ccr = (u64)(saved_regs[PT_CCR]) & 0xFFFFFFFF;
		/* regs->softe is left unchanged (like the MSR.EE bit) */
		/******************************************************/
		/* the DAR and the DSISR are only relevant during a   */
		/*   data or instruction storage interrupt. The value */
		/*   will be set to zero.                             */
		/******************************************************/
		regs->dar = 0; 
		regs->dsisr = 0;
		regs->result = (u64)(saved_regs[PT_RESULT]) & 0xFFFFFFFF;

		if (copy_from_user(current->thread.fpr, &sr->fp_regs, sizeof(sr->fp_regs)))
			goto badframe;

		ret = regs->result;
	} else {
		/* More signals to go */
		regs->gpr[1] = (unsigned long)sc - __SIGNAL_FRAMESIZE32;
		if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
			goto badframe;