2008-05-19 17:52:27 -06:00
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/*
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2005-04-16 16:20:36 -06:00
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* arch/sparc64/kernel/signal.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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2008-07-31 21:40:46 -06:00
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* Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
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2005-04-16 16:20:36 -06:00
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* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
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* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
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* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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2008-04-26 04:17:12 -06:00
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#ifdef CONFIG_COMPAT
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2005-04-16 16:20:36 -06:00
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#include <linux/compat.h> /* for compat_old_sigset_t */
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#endif
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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2008-04-20 16:06:49 -06:00
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#include <linux/tracehook.h>
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2005-04-16 16:20:36 -06:00
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#include <linux/unistd.h>
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#include <linux/mm.h>
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#include <linux/tty.h>
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#include <linux/binfmts.h>
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#include <linux/bitops.h>
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#include <asm/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/pgtable.h>
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#include <asm/fpumacro.h>
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#include <asm/uctx.h>
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#include <asm/siginfo.h>
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#include <asm/visasm.h>
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2012-03-28 11:30:03 -06:00
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#include <asm/switch_to.h>
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#include <asm/cacheflush.h>
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2005-04-16 16:20:36 -06:00
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2008-03-26 02:52:18 -06:00
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#include "entry.h"
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#include "systbls.h"
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2011-08-20 18:14:54 -06:00
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#include "sigutil.h"
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2008-03-26 02:52:18 -06:00
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2005-04-16 16:20:36 -06:00
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/* {set, get}context() needed for 64-bit SparcLinux userland. */
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asmlinkage void sparc64_set_context(struct pt_regs *regs)
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{
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struct ucontext __user *ucp = (struct ucontext __user *)
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regs->u_regs[UREG_I0];
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mc_gregset_t __user *grp;
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unsigned long pc, npc, tstate;
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unsigned long fp, i7;
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unsigned char fenab;
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int err;
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flush_user_windows();
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if (get_thread_wsaved() ||
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(((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
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(!__access_ok(ucp, sizeof(*ucp))))
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goto do_sigsegv;
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grp = &ucp->uc_mcontext.mc_gregs;
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err = __get_user(pc, &((*grp)[MC_PC]));
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err |= __get_user(npc, &((*grp)[MC_NPC]));
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if (err || ((pc | npc) & 3))
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goto do_sigsegv;
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if (regs->u_regs[UREG_I1]) {
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sigset_t set;
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if (_NSIG_WORDS == 1) {
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if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
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goto do_sigsegv;
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} else {
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if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
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goto do_sigsegv;
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}
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2011-08-11 07:57:02 -06:00
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set_current_blocked(&set);
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2005-04-16 16:20:36 -06:00
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}
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if (test_thread_flag(TIF_32BIT)) {
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pc &= 0xffffffff;
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npc &= 0xffffffff;
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}
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regs->tpc = pc;
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regs->tnpc = npc;
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err |= __get_user(regs->y, &((*grp)[MC_Y]));
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err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
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regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
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regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
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err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
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err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
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err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
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err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
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err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
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err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
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2008-07-31 21:40:46 -06:00
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/* Skip %g7 as that's the thread register in userspace. */
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2005-04-16 16:20:36 -06:00
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err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
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err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
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err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
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err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
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err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
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err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
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err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
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err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
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err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
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err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
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err |= __put_user(fp,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
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err |= __put_user(i7,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
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err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
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if (fenab) {
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unsigned long *fpregs = current_thread_info()->fpregs;
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unsigned long fprs;
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fprs_write(0);
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err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
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if (fprs & FPRS_DL)
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err |= copy_from_user(fpregs,
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
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(sizeof(unsigned int) * 32));
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if (fprs & FPRS_DU)
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err |= copy_from_user(fpregs+16,
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((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
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(sizeof(unsigned int) * 32));
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err |= __get_user(current_thread_info()->xfsr[0],
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
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err |= __get_user(current_thread_info()->gsr[0],
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&(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
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regs->tstate &= ~TSTATE_PEF;
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}
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if (err)
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goto do_sigsegv;
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return;
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do_sigsegv:
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force_sig(SIGSEGV, current);
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}
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asmlinkage void sparc64_get_context(struct pt_regs *regs)
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{
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struct ucontext __user *ucp = (struct ucontext __user *)
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regs->u_regs[UREG_I0];
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mc_gregset_t __user *grp;
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mcontext_t __user *mcp;
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unsigned long fp, i7;
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unsigned char fenab;
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int err;
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synchronize_user_stack();
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if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
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goto do_sigsegv;
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#if 1
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fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
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#else
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fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
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#endif
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mcp = &ucp->uc_mcontext;
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grp = &mcp->mc_gregs;
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/* Skip over the trap instruction, first. */
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if (test_thread_flag(TIF_32BIT)) {
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regs->tpc = (regs->tnpc & 0xffffffff);
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regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
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} else {
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regs->tpc = regs->tnpc;
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regs->tnpc += 4;
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}
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err = 0;
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if (_NSIG_WORDS == 1)
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err |= __put_user(current->blocked.sig[0],
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(unsigned long __user *)&ucp->uc_sigmask);
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else
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err |= __copy_to_user(&ucp->uc_sigmask, ¤t->blocked,
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sizeof(sigset_t));
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err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
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err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
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err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
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err |= __put_user(regs->y, &((*grp)[MC_Y]));
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err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
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err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
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err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
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err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
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err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
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err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
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err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
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err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
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err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
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err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
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err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
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err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
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err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
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err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
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err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
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err |= __get_user(fp,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
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err |= __get_user(i7,
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(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
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err |= __put_user(fp, &(mcp->mc_fp));
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err |= __put_user(i7, &(mcp->mc_i7));
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err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
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if (fenab) {
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unsigned long *fpregs = current_thread_info()->fpregs;
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unsigned long fprs;
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fprs = current_thread_info()->fpsaved[0];
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if (fprs & FPRS_DL)
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err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
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(sizeof(unsigned int) * 32));
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if (fprs & FPRS_DU)
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err |= copy_to_user(
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((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
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(sizeof(unsigned int) * 32));
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err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
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err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
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err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
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}
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if (err)
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goto do_sigsegv;
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return;
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do_sigsegv:
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force_sig(SIGSEGV, current);
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}
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struct rt_signal_frame {
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struct sparc_stackf ss;
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siginfo_t info;
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struct pt_regs regs;
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__siginfo_fpu_t __user *fpu_save;
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stack_t stack;
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sigset_t mask;
|
2011-08-20 18:14:54 -06:00
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__siginfo_rwin_t *rwin_save;
|
2005-04-16 16:20:36 -06:00
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};
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void do_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_signal_frame __user *sf;
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unsigned long tpc, tnpc, tstate;
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__siginfo_fpu_t __user *fpu_save;
|
2011-08-20 18:14:54 -06:00
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__siginfo_rwin_t __user *rwin_save;
|
2005-04-16 16:20:36 -06:00
|
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sigset_t set;
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int err;
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|
|
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/* Always make any pending restarted system calls return -EINTR */
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current_thread_info()->restart_block.fn = do_no_restart_syscall;
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synchronize_user_stack ();
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sf = (struct rt_signal_frame __user *)
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(regs->u_regs [UREG_FP] + STACK_BIAS);
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/* 1. Make sure we are not getting garbage from the user */
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if (((unsigned long) sf) & 3)
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goto segv;
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err = get_user(tpc, &sf->regs.tpc);
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err |= __get_user(tnpc, &sf->regs.tnpc);
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if (test_thread_flag(TIF_32BIT)) {
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tpc &= 0xffffffff;
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tnpc &= 0xffffffff;
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}
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err |= ((tpc | tnpc) & 3);
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/* 2. Restore the state */
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err |= __get_user(regs->y, &sf->regs.y);
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err |= __get_user(tstate, &sf->regs.tstate);
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err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
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/* User can only change condition codes and %asi in %tstate. */
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regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
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regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
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err |= __get_user(fpu_save, &sf->fpu_save);
|
2011-08-20 18:14:54 -06:00
|
|
|
if (!err && fpu_save)
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err |= restore_fpu_state(regs, fpu_save);
|
2005-04-16 16:20:36 -06:00
|
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err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
|
2012-12-23 01:41:17 -07:00
|
|
|
err |= restore_altstack(&sf->stack);
|
|
|
|
if (err)
|
2005-04-16 16:20:36 -06:00
|
|
|
goto segv;
|
2007-07-17 15:37:54 -06:00
|
|
|
|
2011-08-20 18:14:54 -06:00
|
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|
err |= __get_user(rwin_save, &sf->rwin_save);
|
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|
|
if (!err && rwin_save) {
|
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|
|
if (restore_rwin_state(rwin_save))
|
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|
|
goto segv;
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
regs->tpc = tpc;
|
|
|
|
regs->tnpc = tnpc;
|
|
|
|
|
2008-05-01 04:30:22 -06:00
|
|
|
/* Prevent syscall restart. */
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
pt_regs_clear_syscall(regs);
|
2008-05-01 04:30:22 -06:00
|
|
|
|
2011-08-11 07:57:02 -06:00
|
|
|
set_current_blocked(&set);
|
2005-04-16 16:20:36 -06:00
|
|
|
return;
|
|
|
|
segv:
|
|
|
|
force_sig(SIGSEGV, current);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Checks if the fp is valid */
|
2011-08-20 18:14:54 -06:00
|
|
|
static int invalid_frame_pointer(void __user *fp)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-02-09 17:18:40 -07:00
|
|
|
if (((unsigned long) fp) & 15)
|
2005-04-16 16:20:36 -06:00
|
|
|
return 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2012-11-07 21:48:13 -07:00
|
|
|
static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2008-05-07 19:54:05 -06:00
|
|
|
unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-05-07 19:54:05 -06:00
|
|
|
/*
|
|
|
|
* If we are on the alternate signal stack and would overflow it, don't.
|
|
|
|
* Return an always-bogus address instead so we will die with SIGSEGV.
|
|
|
|
*/
|
|
|
|
if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
|
|
|
|
return (void __user *) -1L;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* This is the X/Open sanctioned signal stack switching. */
|
2012-11-07 21:48:13 -07:00
|
|
|
sp = sigsp(sp, ksig) - framesize;
|
2010-02-09 17:18:40 -07:00
|
|
|
|
2008-05-07 19:54:05 -06:00
|
|
|
/* Always align the stack frame. This handles two cases. First,
|
|
|
|
* sigaltstack need not be mindful of platform specific stack
|
|
|
|
* alignment. Second, if we took this signal because the stack
|
|
|
|
* is not aligned properly, we'd like to take the signal cleanly
|
|
|
|
* and report that.
|
|
|
|
*/
|
2010-02-09 17:18:40 -07:00
|
|
|
sp &= ~15UL;
|
2008-05-07 19:54:05 -06:00
|
|
|
|
2010-02-09 17:18:40 -07:00
|
|
|
return (void __user *) sp;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2010-09-21 22:41:12 -06:00
|
|
|
static inline int
|
2012-11-07 21:48:13 -07:00
|
|
|
setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct rt_signal_frame __user *sf;
|
2011-08-20 18:14:54 -06:00
|
|
|
int wsaved, err, sf_size;
|
|
|
|
void __user *tail;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* 1. Make sure everything is clean */
|
|
|
|
synchronize_user_stack();
|
|
|
|
save_and_clear_fpu();
|
|
|
|
|
2011-08-20 18:14:54 -06:00
|
|
|
wsaved = get_thread_wsaved();
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-08-20 18:14:54 -06:00
|
|
|
sf_size = sizeof(struct rt_signal_frame);
|
|
|
|
if (current_thread_info()->fpsaved[0] & FPRS_FEF)
|
|
|
|
sf_size += sizeof(__siginfo_fpu_t);
|
|
|
|
if (wsaved)
|
|
|
|
sf_size += sizeof(__siginfo_rwin_t);
|
2005-04-16 16:20:36 -06:00
|
|
|
sf = (struct rt_signal_frame __user *)
|
2012-11-07 21:48:13 -07:00
|
|
|
get_sigframe(ksig, regs, sf_size);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-11-07 21:48:13 -07:00
|
|
|
if (invalid_frame_pointer (sf)) {
|
|
|
|
do_exit(SIGILL); /* won't return, actually */
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-08-20 18:14:54 -06:00
|
|
|
tail = (sf + 1);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/* 2. Save the current process state */
|
|
|
|
err = copy_to_user(&sf->regs, regs, sizeof (*regs));
|
|
|
|
|
|
|
|
if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
|
2011-08-20 18:14:54 -06:00
|
|
|
__siginfo_fpu_t __user *fpu_save = tail;
|
|
|
|
tail += sizeof(__siginfo_fpu_t);
|
|
|
|
err |= save_fpu_state(regs, fpu_save);
|
|
|
|
err |= __put_user((u64)fpu_save, &sf->fpu_save);
|
2005-04-16 16:20:36 -06:00
|
|
|
} else {
|
|
|
|
err |= __put_user(0, &sf->fpu_save);
|
|
|
|
}
|
2011-08-20 18:14:54 -06:00
|
|
|
if (wsaved) {
|
|
|
|
__siginfo_rwin_t __user *rwin_save = tail;
|
|
|
|
tail += sizeof(__siginfo_rwin_t);
|
|
|
|
err |= save_rwin_state(wsaved, rwin_save);
|
|
|
|
err |= __put_user((u64)rwin_save, &sf->rwin_save);
|
|
|
|
set_thread_wsaved(0);
|
|
|
|
} else {
|
|
|
|
err |= __put_user(0, &sf->rwin_save);
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* Setup sigaltstack */
|
2012-12-23 01:41:17 -07:00
|
|
|
err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-11-07 21:48:13 -07:00
|
|
|
err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-08-20 18:14:54 -06:00
|
|
|
if (!wsaved) {
|
|
|
|
err |= copy_in_user((u64 __user *)sf,
|
|
|
|
(u64 __user *)(regs->u_regs[UREG_FP] +
|
|
|
|
STACK_BIAS),
|
|
|
|
sizeof(struct reg_window));
|
|
|
|
} else {
|
|
|
|
struct reg_window *rp;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-08-20 18:14:54 -06:00
|
|
|
rp = ¤t_thread_info()->reg_window[wsaved - 1];
|
|
|
|
err |= copy_to_user(sf, rp, sizeof(struct reg_window));
|
|
|
|
}
|
2012-11-07 21:48:13 -07:00
|
|
|
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
|
|
|
|
err |= copy_siginfo_to_user(&sf->info, &ksig->info);
|
2005-04-16 16:20:36 -06:00
|
|
|
else {
|
2012-11-07 21:48:13 -07:00
|
|
|
err |= __put_user(ksig->sig, &sf->info.si_signo);
|
2005-04-16 16:20:36 -06:00
|
|
|
err |= __put_user(SI_NOINFO, &sf->info.si_code);
|
|
|
|
}
|
|
|
|
if (err)
|
2012-11-07 21:48:13 -07:00
|
|
|
return err;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* 3. signal handler back-trampoline and parameters */
|
|
|
|
regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
|
2012-11-07 21:48:13 -07:00
|
|
|
regs->u_regs[UREG_I0] = ksig->sig;
|
2005-04-16 16:20:36 -06:00
|
|
|
regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
|
|
|
|
|
|
|
|
/* The sigcontext is passed in this way because of how it
|
|
|
|
* is defined in GLIBC's /usr/include/bits/sigcontext.h
|
|
|
|
* for sparc64. It includes the 128 bytes of siginfo_t.
|
|
|
|
*/
|
|
|
|
regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
|
|
|
|
|
|
|
|
/* 5. signal handler */
|
2012-11-07 21:48:13 -07:00
|
|
|
regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
|
2005-04-16 16:20:36 -06:00
|
|
|
regs->tnpc = (regs->tpc + 4);
|
|
|
|
if (test_thread_flag(TIF_32BIT)) {
|
|
|
|
regs->tpc &= 0xffffffff;
|
|
|
|
regs->tnpc &= 0xffffffff;
|
|
|
|
}
|
|
|
|
/* 4. return to kernel instructions */
|
2012-11-07 21:48:13 -07:00
|
|
|
regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
|
2010-09-21 22:41:12 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
struct sigaction *sa)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
switch (regs->u_regs[UREG_I0]) {
|
|
|
|
case ERESTART_RESTARTBLOCK:
|
|
|
|
case ERESTARTNOHAND:
|
|
|
|
no_system_call_restart:
|
|
|
|
regs->u_regs[UREG_I0] = EINTR;
|
|
|
|
regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
|
|
|
|
break;
|
|
|
|
case ERESTARTSYS:
|
|
|
|
if (!(sa->sa_flags & SA_RESTART))
|
|
|
|
goto no_system_call_restart;
|
|
|
|
/* fallthrough */
|
|
|
|
case ERESTARTNOINTR:
|
|
|
|
regs->u_regs[UREG_I0] = orig_i0;
|
|
|
|
regs->tpc -= 4;
|
|
|
|
regs->tnpc -= 4;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* 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.
|
|
|
|
*/
|
2008-04-24 04:01:48 -06:00
|
|
|
static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2012-11-07 21:48:13 -07:00
|
|
|
struct ksignal ksig;
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
int restart_syscall;
|
2012-11-07 21:48:13 -07:00
|
|
|
bool has_handler;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-11-14 21:32:16 -07:00
|
|
|
/* It's a lot of work and synchronization to add a new ptrace
|
|
|
|
* register for GDB to save and restore in order to get
|
|
|
|
* orig_i0 correct for syscall restarts when debugging.
|
|
|
|
*
|
2011-11-15 13:57:00 -07:00
|
|
|
* Although it should be the case that most of the global
|
|
|
|
* registers are volatile across a system call, glibc already
|
|
|
|
* depends upon that fact that we preserve them. So we can't
|
|
|
|
* just use any global register to save away the orig_i0 value.
|
|
|
|
*
|
|
|
|
* In particular %g2, %g3, %g4, and %g5 are all assumed to be
|
|
|
|
* preserved across a system call trap by various pieces of
|
|
|
|
* code in glibc.
|
|
|
|
*
|
|
|
|
* %g7 is used as the "thread register". %g6 is not used in
|
|
|
|
* any fixed manner. %g6 is used as a scratch register and
|
|
|
|
* a compiler temporary, but it's value is never used across
|
|
|
|
* a system call. Therefore %g6 is usable for orig_i0 storage.
|
2011-11-14 21:32:16 -07:00
|
|
|
*/
|
2008-05-01 04:30:22 -06:00
|
|
|
if (pt_regs_is_syscall(regs) &&
|
2011-11-14 21:32:16 -07:00
|
|
|
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
|
2011-11-15 13:57:00 -07:00
|
|
|
regs->u_regs[UREG_G6] = orig_i0;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-04-26 04:17:12 -06:00
|
|
|
#ifdef CONFIG_COMPAT
|
2005-04-16 16:20:36 -06:00
|
|
|
if (test_thread_flag(TIF_32BIT)) {
|
2012-11-07 21:48:13 -07:00
|
|
|
extern void do_signal32(struct pt_regs *);
|
|
|
|
do_signal32(regs);
|
2006-01-19 03:42:49 -07:00
|
|
|
return;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
2012-11-07 21:48:13 -07:00
|
|
|
has_handler = get_signal(&ksig);
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
|
2011-11-14 21:32:16 -07:00
|
|
|
restart_syscall = 0;
|
|
|
|
if (pt_regs_is_syscall(regs) &&
|
|
|
|
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
|
|
|
|
restart_syscall = 1;
|
2011-11-15 13:57:00 -07:00
|
|
|
orig_i0 = regs->u_regs[UREG_G6];
|
2011-11-14 21:32:16 -07:00
|
|
|
}
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
|
2012-11-07 21:48:13 -07:00
|
|
|
if (has_handler) {
|
sparc: Fix debugger syscall restart interactions.
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 03:07:19 -06:00
|
|
|
if (restart_syscall)
|
2012-11-07 21:48:13 -07:00
|
|
|
syscall_restart(orig_i0, regs, &ksig.ka.sa);
|
|
|
|
signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
|
|
|
|
} else {
|
|
|
|
if (restart_syscall) {
|
|
|
|
switch (regs->u_regs[UREG_I0]) {
|
|
|
|
case ERESTARTNOHAND:
|
|
|
|
case ERESTARTSYS:
|
|
|
|
case ERESTARTNOINTR:
|
|
|
|
/* replay the system call when we are done */
|
|
|
|
regs->u_regs[UREG_I0] = orig_i0;
|
|
|
|
regs->tpc -= 4;
|
|
|
|
regs->tnpc -= 4;
|
|
|
|
pt_regs_clear_syscall(regs);
|
|
|
|
case ERESTART_RESTARTBLOCK:
|
|
|
|
regs->u_regs[UREG_G1] = __NR_restart_syscall;
|
|
|
|
regs->tpc -= 4;
|
|
|
|
regs->tnpc -= 4;
|
|
|
|
pt_regs_clear_syscall(regs);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
restore_saved_sigmask();
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2008-04-24 04:15:22 -06:00
|
|
|
void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2008-05-12 23:45:15 -06:00
|
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
2008-04-24 04:01:48 -06:00
|
|
|
do_signal(regs, orig_i0);
|
2008-04-20 16:06:49 -06:00
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
|
|
tracehook_notify_resume(regs);
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]
Add a keyctl to install a process's session keyring onto its parent. This
replaces the parent's session keyring. Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again. Normally this
will be after a wait*() syscall.
To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.
The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.
Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the
replacement to be performed at the point the parent process resumes userspace
execution.
This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership. However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.
This can be tested with the following program:
#include <stdio.h>
#include <stdlib.h>
#include <keyutils.h>
#define KEYCTL_SESSION_TO_PARENT 18
#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)
int main(int argc, char **argv)
{
key_serial_t keyring, key;
long ret;
keyring = keyctl_join_session_keyring(argv[1]);
OSERROR(keyring, "keyctl_join_session_keyring");
key = add_key("user", "a", "b", 1, keyring);
OSERROR(key, "add_key");
ret = keyctl(KEYCTL_SESSION_TO_PARENT);
OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");
return 0;
}
Compiled and linked with -lkeyutils, you should see something like:
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
355907932 --alswrv 4043 -1 \_ keyring: _uid.4043
[dhowells@andromeda ~]$ /tmp/newpag
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
1055658746 --alswrv 4043 4043 \_ user: a
[dhowells@andromeda ~]$ /tmp/newpag hello
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: hello
340417692 --alswrv 4043 4043 \_ user: a
Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 02:14:21 -06:00
|
|
|
|