patch-2.4.20 linux-2.4.20/arch/x86_64/ia32/ia32_signal.c

• Lines: 525
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/arch/x86_64/ia32/ia32_signal.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/x86_64/ia32/ia32_signal.c linux-2.4.20/arch/x86_64/ia32/ia32_signal.c
@@ -0,0 +1,524 @@
+/*
+ *  linux/arch/x86_64/ia32/ia32_signal.c
+ *
+ *  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
+ *  2000-12-*   x86-64 compatibility mode signal handling by Andi Kleen
+ * 
+ *  $Id: ia32_signal.c,v 1.22 2002/07/29 10:34:03 ak Exp $
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/i387.h>
+#include <asm/ia32.h>
+#include <asm/ptrace.h>
+#include <asm/ia32_unistd.h>
+#include <asm/user32.h>
+#include <asm/sigcontext32.h>
+#include <asm/fpu32.h>
+
+#define ptr_to_u32(x) ((u32)(u64)(x))	/* avoid gcc warning */ 
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+void signal_fault(struct pt_regs *regs, void *frame, char *where);
+
+static int ia32_copy_siginfo_to_user(siginfo_t32 *to, siginfo_t *from)
+{
+	if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t)))
+		return -EFAULT;
+	if (from->si_code < 0)
+		return __copy_to_user(to, from, sizeof(siginfo_t));
+	else {
+		int err;
+
+		/* If you change siginfo_t structure, please be sure
+		   this code is fixed accordingly.
+		   It should never copy any pad contained in the structure
+		   to avoid security leaks, but must copy the generic
+		   3 ints plus the relevant union member.  */
+		err = __put_user(from->si_signo, &to->si_signo);
+		err |= __put_user(from->si_errno, &to->si_errno);
+		err |= __put_user((short)from->si_code, &to->si_code);
+		/* First 32bits of unions are always present.  */
+		err |= __put_user(from->si_pid, &to->si_pid);
+		switch (from->si_code >> 16) {
+		case __SI_FAULT >> 16:
+			break;
+		case __SI_CHLD >> 16:
+			err |= __put_user(from->si_utime, &to->si_utime);
+			err |= __put_user(from->si_stime, &to->si_stime);
+			err |= __put_user(from->si_status, &to->si_status);
+		default:
+			err |= __put_user(from->si_uid, &to->si_uid);
+			break;
+		/* case __SI_RT: This is not generated by the kernel as of now.  */
+		}
+		return err;
+	}
+}
+
+asmlinkage int
+sys32_sigsuspend(int history0, int history1, old_sigset_t mask, struct pt_regs regs)
+{
+	sigset_t saveset;
+
+	mask &= _BLOCKABLE;
+	spin_lock_irq(&current->sigmask_lock);
+	saveset = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+
+	regs.rax = -EINTR;
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		if (do_signal(&regs, &saveset))
+			return -EINTR;
+	}
+}
+
+asmlinkage int
+sys32_sigaltstack(const stack_ia32_t *uss_ptr, stack_ia32_t *uoss_ptr, 
+				  struct pt_regs regs)
+{
+	stack_t uss,uoss; 
+	int ret;
+	mm_segment_t seg; 
+	if (!access_ok(VERIFY_READ,uss_ptr,sizeof(stack_ia32_t)) ||
+	    __get_user(ptr_to_u32(uss.ss_sp), &uss_ptr->ss_sp) ||
+	    __get_user((u32)uss.ss_flags, &uss_ptr->ss_flags) ||
+	    __get_user((u32)uss.ss_size, &uss_ptr->ss_size))
+		return -EFAULT;
+	seg = get_fs(); 
+	set_fs(KERNEL_DS); 
+	ret = do_sigaltstack(&uss, &uoss, regs.rsp);
+	set_fs(seg); 
+	if (ret >= 0 && uoss_ptr)  {
+		if (!access_ok(VERIFY_WRITE,uss_ptr,sizeof(stack_ia32_t)) ||
+		    __put_user(ptr_to_u32(uss.ss_sp), &uss_ptr->ss_sp) ||
+		    __put_user((u32)uss.ss_flags, &uss_ptr->ss_flags) ||
+		    __put_user((u32)uss.ss_size, &uss_ptr->ss_size))
+			ret = -EFAULT;
+	} 	
+	return ret;	
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe
+{
+	u32 pretcode;
+	int sig;
+	struct sigcontext_ia32 sc;
+	struct _fpstate_ia32 fpstate;
+	unsigned int extramask[_IA32_NSIG_WORDS-1];
+	char retcode[8];
+};
+
+struct rt_sigframe
+{
+	u32 pretcode;
+	int sig;
+	u32 pinfo;
+	u32 puc;
+	struct siginfo32 info;
+	struct ucontext_ia32 uc;
+	struct _fpstate_ia32 fpstate;
+	char retcode[8];
+};
+
+static int
+ia32_restore_sigcontext(struct pt_regs *regs, struct sigcontext_ia32 *sc, unsigned int *peax)
+{
+	unsigned int err = 0;
+	
+#if DEBUG_SIG
+	printk("SIG restore_sigcontext: sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
+		sc, sc->err, sc->eip, sc->cs, sc->eflags);
+#endif
+#define COPY(x)		{ \
+	unsigned int reg;	\
+	err |= __get_user(reg, &sc->e ##x);	\
+	regs->r ## x = reg;			\
+}
+
+#define RELOAD_SEG(seg,mask)						\
+	{ unsigned int cur; 				\
+	  unsigned short pre;				\
+	  err |= __get_user(pre, &sc->seg);				\
+    	  asm volatile("movl %%" #seg ",%0" : "=r" (cur));		\
+	  pre |= mask; 							\
+	  if (pre != cur) loadsegment(seg,pre); }
+
+	/* Reload fs and gs if they have changed in the signal handler.
+	   This does not handle long fs/gs base changes in the handler, but 
+	   does not clobber them at least in the normal case. */ 
+	
+	{
+		unsigned short gs; 
+		err |= __get_user(gs, &sc->gs);
+		load_gs_index(gs); 
+	} 
+	RELOAD_SEG(fs,0);
+	RELOAD_SEG(ds,0);
+	RELOAD_SEG(es,0);
+
+	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+	COPY(dx); COPY(cx); COPY(ip);
+	/* Don't touch extended registers */ 
+
+#if 1	/* not ready for this yet */ 
+	err |= __get_user(regs->cs, &sc->cs); 
+	regs->cs |= 2; 	
+	err |= __get_user(regs->ss, &sc->ss); 
+	regs->ss |= 2; 
+#else
+	regs->cs = __USER32_CS;
+	regs->ss = __USER32_DS; 
+#endif
+	
+	{
+		unsigned int tmpflags;
+		err |= __get_user(tmpflags, &sc->eflags);
+		regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
+		regs->orig_rax = -1;		/* disable syscall checks */
+	}
+
+	{
+		u32 tmp;
+		struct _fpstate_ia32 * buf;
+		err |= __get_user(tmp, &sc->fpstate);
+		buf = (struct _fpstate_ia32 *) (u64)tmp;
+		if (buf) {
+			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
+				goto badframe;
+			err |= restore_i387_ia32(current, buf, 0);
+		}
+	}
+
+	{ 
+		u32 tmp;
+		err |= __get_user(tmp, &sc->eax);
+		*peax = tmp;
+	}
+	return err;
+
+badframe:
+	return 1;
+}
+
+asmlinkage int sys32_sigreturn(struct pt_regs regs)
+{
+	struct sigframe *frame = (struct sigframe *)(regs.rsp - 8);
+	sigset_t set;
+	unsigned int eax;
+
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], &frame->sc.oldmask)
+	    || (_IA32_NSIG_WORDS > 1
+		&& __copy_from_user((((char *) &set.sig) + 4), &frame->extramask,
+				    sizeof(frame->extramask))))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sigmask_lock);
+	current->blocked = set;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+	
+	if (ia32_restore_sigcontext(&regs, &frame->sc, &eax))
+		goto badframe;
+	return eax;
+
+badframe:
+	signal_fault(&regs,frame,"32bit sigreturn");
+	return 0;
+}	
+
+asmlinkage int sys32_rt_sigreturn(struct pt_regs regs)
+{
+	struct rt_sigframe *frame = (struct rt_sigframe *)(regs.rsp - 4);
+	sigset_t set;
+	stack_t st;
+	unsigned int eax;
+
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sigmask_lock);
+	current->blocked = set;
+	recalc_sigpending(current);
+	spin_unlock_irq(&current->sigmask_lock);
+	
+	if (ia32_restore_sigcontext(&regs, &frame->uc.uc_mcontext, &eax))
+		goto badframe;
+
+	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
+		goto badframe;
+	/* It is more difficult to avoid calling this function than to
+	   call it and ignore errors.  */
+	{
+		mm_segment_t oldds = get_fs(); 
+		set_fs(KERNEL_DS); 
+		do_sigaltstack(&st, NULL, regs.rsp);
+		set_fs(oldds);  
+	}
+
+	return eax;
+
+badframe:
+	signal_fault(&regs,frame,"32bit rt sigreturn");
+	return 0;
+}	
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+ia32_setup_sigcontext(struct sigcontext_ia32 *sc, struct _fpstate_ia32 *fpstate,
+		 struct pt_regs *regs, unsigned int mask)
+{
+	int tmp, err = 0;
+
+	tmp = 0;
+	__asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
+	err |= __put_user(tmp, (unsigned int *)&sc->gs);
+	__asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
+	err |= __put_user(tmp, (unsigned int *)&sc->fs);
+	__asm__("movl %%ds,%0" : "=r"(tmp): "0"(tmp));
+	err |= __put_user(tmp, (unsigned int *)&sc->ds);
+	__asm__("movl %%es,%0" : "=r"(tmp): "0"(tmp));
+	err |= __put_user(tmp, (unsigned int *)&sc->es);
+
+	err |= __put_user((u32)regs->rdi, &sc->edi);
+	err |= __put_user((u32)regs->rsi, &sc->esi);
+	err |= __put_user((u32)regs->rbp, &sc->ebp);
+	err |= __put_user((u32)regs->rsp, &sc->esp);
+	err |= __put_user((u32)regs->rbx, &sc->ebx);
+	err |= __put_user((u32)regs->rdx, &sc->edx);
+	err |= __put_user((u32)regs->rcx, &sc->ecx);
+	err |= __put_user((u32)regs->rax, &sc->eax);
+	err |= __put_user((u32)regs->cs, &sc->cs); 
+	err |= __put_user((u32)regs->ss, &sc->ss); 
+	err |= __put_user(current->thread.trap_no, &sc->trapno);
+	err |= __put_user(current->thread.error_code, &sc->err);
+	err |= __put_user((u32)regs->rip, &sc->eip);
+	err |= __put_user((u32)regs->eflags, &sc->eflags);
+	err |= __put_user((u32)regs->rsp, &sc->esp_at_signal);
+
+	tmp = save_i387_ia32(current, fpstate, regs, 0);
+	if (tmp < 0)
+	  err = -EFAULT;
+	else
+	  err |= __put_user((u32)(u64)(tmp ? fpstate : NULL), &sc->fpstate);
+
+	/* non-iBCS2 extensions.. */
+	err |= __put_user(mask, &sc->oldmask);
+	err |= __put_user(current->thread.cr2, &sc->cr2);
+
+	return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void *
+get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+{
+	unsigned long rsp;
+
+	/* Default to using normal stack */
+	rsp = regs->rsp;
+
+	/* This is the X/Open sanctioned signal stack switching.  */
+	if (ka->sa.sa_flags & SA_ONSTACK) {
+		if (! on_sig_stack(rsp))
+			rsp = current->sas_ss_sp + current->sas_ss_size;
+	}
+
+	/* This is the legacy signal stack switching. */
+	else if ((regs->ss & 0xffff) != __USER_DS &&
+		!(ka->sa.sa_flags & SA_RESTORER) &&
+		 ka->sa.sa_restorer) {
+		rsp = (unsigned long) ka->sa.sa_restorer;
+	}
+
+	return (void *)((rsp - frame_size) & -8UL);
+}
+
+void ia32_setup_frame(int sig, struct k_sigaction *ka,
+			sigset32_t *set, struct pt_regs * regs)
+{
+	struct sigframe *frame;
+	int err = 0;
+
+	frame = get_sigframe(ka, regs, sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	err |= __put_user((current->exec_domain
+		           && current->exec_domain->signal_invmap
+		           && sig < 32
+		           ? current->exec_domain->signal_invmap[sig]
+		           : sig),
+		          &frame->sig);
+	if (err)
+		goto give_sigsegv;
+
+	err |= ia32_setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
+	if (err)
+		goto give_sigsegv;
+
+	if (_IA32_NSIG_WORDS > 1) {
+		err |= __copy_to_user(frame->extramask, &set->sig[1],
+				      sizeof(frame->extramask));
+	}
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		err |= __put_user((u32)(u64)ka->sa.sa_restorer, &frame->pretcode);
+	} else {
+		err |= __put_user((u32)(u64)frame->retcode, &frame->pretcode);
+		/* This is popl %eax ; movl $,%eax ; int $0x80 */
+		err |= __put_user((u16)0xb858, (short *)(frame->retcode+0));
+		err |= __put_user((u32)__NR_ia32_sigreturn, (int *)(frame->retcode+2));
+		err |= __put_user((u16)0x80cd, (short *)(frame->retcode+6));
+	}
+
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->rsp = (unsigned long) frame;
+	regs->rip = (unsigned long) ka->sa.sa_handler;
+
+	asm volatile("movl %0,%%ds" :: "r" (__USER32_DS)); 
+	asm volatile("movl %0,%%es" :: "r" (__USER32_DS)); 
+
+	regs->cs = __USER32_CS; 
+	regs->ss = __USER32_DS; 
+
+	set_fs(USER_DS);
+	regs->eflags &= ~TF_MASK;
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->rip, frame->pretcode);
+#endif
+
+	return;
+
+give_sigsegv:
+	if (sig == SIGSEGV)
+		ka->sa.sa_handler = SIG_DFL;
+	signal_fault(regs,frame,"32bit signal deliver");
+}
+
+void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+			   sigset32_t *set, struct pt_regs * regs)
+{
+	struct rt_sigframe *frame;
+	int err = 0;
+
+	frame = get_sigframe(ka, regs, sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	err |= __put_user((current->exec_domain
+		    	   && current->exec_domain->signal_invmap
+		    	   && sig < 32
+		    	   ? current->exec_domain->signal_invmap[sig]
+			   : sig),
+			  &frame->sig);
+	err |= __put_user((u32)(u64)&frame->info, &frame->pinfo);
+	err |= __put_user((u32)(u64)&frame->uc, &frame->puc);
+	err |= ia32_copy_siginfo_to_user(&frame->info, info);
+	if (err)
+		goto give_sigsegv;
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(regs->rsp),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
+			        regs, set->sig[0]);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		err |= __put_user((u32)(u64)ka->sa.sa_restorer, &frame->pretcode);
+	} else {
+		err |= __put_user(ptr_to_u32(frame->retcode), &frame->pretcode);
+		/* This is movl $,%eax ; int $0x80 */
+		err |= __put_user(0xb8, (char *)(frame->retcode+0));
+		err |= __put_user((u32)__NR_ia32_rt_sigreturn, (int *)(frame->retcode+1));
+		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
+	}
+
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up registers for signal handler */
+	regs->rsp = (unsigned long) frame;
+	regs->rip = (unsigned long) ka->sa.sa_handler;
+
+	asm volatile("movl %0,%%ds" :: "r" (__USER32_DS)); 
+	asm volatile("movl %0,%%es" :: "r" (__USER32_DS)); 
+
+	regs->cs = __USER32_CS; 
+	regs->ss = __USER32_DS; 
+
+	set_fs(USER_DS);
+	regs->eflags &= ~TF_MASK;
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->rip, frame->pretcode);
+#endif
+
+	return;
+
+give_sigsegv:
+	if (sig == SIGSEGV)
+		ka->sa.sa_handler = SIG_DFL;
+	signal_fault(regs,frame,"32bit rt signal deliver");
+}
+