UML: change sigcontext fields to match x86
[sfrench/cifs-2.6.git] / arch / um / sys-i386 / signal.c
index 3f6acd6677179ff30d1cd3b2a3ecac39195466dd..19053d46cb60190421d818435af10bac6ce2bbfb 100644 (file)
 /*
- * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "linux/signal.h"
-#include "linux/ptrace.h"
-#include "asm/current.h"
-#include "asm/ucontext.h"
-#include "asm/uaccess.h"
-#include "asm/unistd.h"
+#include <linux/ptrace.h>
+#include <asm/unistd.h>
+#include <asm/uaccess.h>
+#include <asm/ucontext.h>
 #include "frame_kern.h"
-#include "sigcontext.h"
-#include "registers.h"
-#include "mode.h"
+#include "skas.h"
 
-#ifdef CONFIG_MODE_SKAS
+void copy_sc(struct uml_pt_regs *regs, void *from)
+{
+       struct sigcontext *sc = from;
+
+       REGS_GS(regs->gp) = sc->gs;
+       REGS_FS(regs->gp) = sc->fs;
+       REGS_ES(regs->gp) = sc->es;
+       REGS_DS(regs->gp) = sc->ds;
+       REGS_EDI(regs->gp) = sc->di;
+       REGS_ESI(regs->gp) = sc->si;
+       REGS_EBP(regs->gp) = sc->bp;
+       REGS_SP(regs->gp) = sc->sp;
+       REGS_EBX(regs->gp) = sc->bx;
+       REGS_EDX(regs->gp) = sc->dx;
+       REGS_ECX(regs->gp) = sc->cx;
+       REGS_EAX(regs->gp) = sc->ax;
+       REGS_IP(regs->gp) = sc->ip;
+       REGS_CS(regs->gp) = sc->cs;
+       REGS_EFLAGS(regs->gp) = sc->flags;
+       REGS_SS(regs->gp) = sc->ss;
+}
 
-#include "skas.h"
+/*
+ * FPU tag word conversions.
+ */
 
-static int copy_sc_from_user_skas(struct pt_regs *regs,
-                                 struct sigcontext __user *from)
+static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
 {
-       struct sigcontext sc;
-       unsigned long fpregs[HOST_FP_SIZE];
-       int err;
+       unsigned int tmp; /* to avoid 16 bit prefixes in the code */
+
+       /* Transform each pair of bits into 01 (valid) or 00 (empty) */
+       tmp = ~twd;
+       tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
+       /* and move the valid bits to the lower byte. */
+       tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
+       tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
+       tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
+       return tmp;
+}
 
-       err = copy_from_user(&sc, from, sizeof(sc));
-       err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
-       if(err)
-               return(err);
-
-       REGS_GS(regs->regs.skas.regs) = sc.gs;
-       REGS_FS(regs->regs.skas.regs) = sc.fs;
-       REGS_ES(regs->regs.skas.regs) = sc.es;
-       REGS_DS(regs->regs.skas.regs) = sc.ds;
-       REGS_EDI(regs->regs.skas.regs) = sc.edi;
-       REGS_ESI(regs->regs.skas.regs) = sc.esi;
-       REGS_EBP(regs->regs.skas.regs) = sc.ebp;
-       REGS_SP(regs->regs.skas.regs) = sc.esp;
-       REGS_EBX(regs->regs.skas.regs) = sc.ebx;
-       REGS_EDX(regs->regs.skas.regs) = sc.edx;
-       REGS_ECX(regs->regs.skas.regs) = sc.ecx;
-       REGS_EAX(regs->regs.skas.regs) = sc.eax;
-       REGS_IP(regs->regs.skas.regs) = sc.eip;
-       REGS_CS(regs->regs.skas.regs) = sc.cs;
-       REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags;
-       REGS_SS(regs->regs.skas.regs) = sc.ss;
-
-       err = restore_fp_registers(userspace_pid[0], fpregs);
-       if(err < 0){
-               printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, "
-                      "errno = %d\n", err);
-               return(1);
+static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
+{
+       struct _fpxreg *st = NULL;
+       unsigned long twd = (unsigned long) fxsave->twd;
+       unsigned long tag;
+       unsigned long ret = 0xffff0000;
+       int i;
+
+#define FPREG_ADDR(f, n)       ((char *)&(f)->st_space + (n) * 16);
+
+       for (i = 0; i < 8; i++) {
+               if (twd & 0x1) {
+                       st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
+
+                       switch (st->exponent & 0x7fff) {
+                       case 0x7fff:
+                               tag = 2;                /* Special */
+                               break;
+                       case 0x0000:
+                               if ( !st->significand[0] &&
+                                    !st->significand[1] &&
+                                    !st->significand[2] &&
+                                    !st->significand[3] ) {
+                                       tag = 1;        /* Zero */
+                               } else {
+                                       tag = 2;        /* Special */
+                               }
+                               break;
+                       default:
+                               if (st->significand[3] & 0x8000) {
+                                       tag = 0;        /* Valid */
+                               } else {
+                                       tag = 2;        /* Special */
+                               }
+                               break;
+                       }
+               } else {
+                       tag = 3;                        /* Empty */
+               }
+               ret |= (tag << (2 * i));
+               twd = twd >> 1;
        }
-
-       return(0);
+       return ret;
 }
 
-int copy_sc_to_user_skas(struct sigcontext __user *to, struct _fpstate __user *to_fp,
-                         struct pt_regs *regs, unsigned long sp)
+static int convert_fxsr_to_user(struct _fpstate __user *buf,
+                               struct user_fxsr_struct *fxsave)
 {
-       struct sigcontext sc;
-       unsigned long fpregs[HOST_FP_SIZE];
-       struct faultinfo * fi = &current->thread.arch.faultinfo;
-       int err;
+       unsigned long env[7];
+       struct _fpreg __user *to;
+       struct _fpxreg *from;
+       int i;
+
+       env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
+       env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
+       env[2] = twd_fxsr_to_i387(fxsave);
+       env[3] = fxsave->fip;
+       env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
+       env[5] = fxsave->foo;
+       env[6] = fxsave->fos;
+
+       if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
+               return 1;
+
+       to = &buf->_st[0];
+       from = (struct _fpxreg *) &fxsave->st_space[0];
+       for (i = 0; i < 8; i++, to++, from++) {
+               unsigned long __user *t = (unsigned long __user *)to;
+               unsigned long *f = (unsigned long *)from;
 
-       sc.gs = REGS_GS(regs->regs.skas.regs);
-       sc.fs = REGS_FS(regs->regs.skas.regs);
-       sc.es = REGS_ES(regs->regs.skas.regs);
-       sc.ds = REGS_DS(regs->regs.skas.regs);
-       sc.edi = REGS_EDI(regs->regs.skas.regs);
-       sc.esi = REGS_ESI(regs->regs.skas.regs);
-       sc.ebp = REGS_EBP(regs->regs.skas.regs);
-       sc.esp = sp;
-       sc.ebx = REGS_EBX(regs->regs.skas.regs);
-       sc.edx = REGS_EDX(regs->regs.skas.regs);
-       sc.ecx = REGS_ECX(regs->regs.skas.regs);
-       sc.eax = REGS_EAX(regs->regs.skas.regs);
-       sc.eip = REGS_IP(regs->regs.skas.regs);
-       sc.cs = REGS_CS(regs->regs.skas.regs);
-       sc.eflags = REGS_EFLAGS(regs->regs.skas.regs);
-       sc.esp_at_signal = regs->regs.skas.regs[UESP];
-       sc.ss = regs->regs.skas.regs[SS];
-        sc.cr2 = fi->cr2;
-        sc.err = fi->error_code;
-        sc.trapno = fi->trap_no;
-
-       err = save_fp_registers(userspace_pid[0], fpregs);
-       if(err < 0){
-               printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, "
-                      "errno = %d\n", err);
-               return(1);
+               if (__put_user(*f, t) ||
+                               __put_user(*(f + 1), t + 1) ||
+                               __put_user(from->exponent, &to->exponent))
+                       return 1;
        }
-       to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
-       sc.fpstate = to_fp;
+       return 0;
+}
+
+static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
+                                 struct _fpstate __user *buf)
+{
+       unsigned long env[7];
+       struct _fpxreg *to;
+       struct _fpreg __user *from;
+       int i;
 
-       if(err)
-               return(err);
+       if (copy_from_user( env, buf, 7 * sizeof(long)))
+               return 1;
 
-       return(copy_to_user(to, &sc, sizeof(sc)) ||
-              copy_to_user(to_fp, fpregs, sizeof(fpregs)));
+       fxsave->cwd = (unsigned short)(env[0] & 0xffff);
+       fxsave->swd = (unsigned short)(env[1] & 0xffff);
+       fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
+       fxsave->fip = env[3];
+       fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
+       fxsave->fcs = (env[4] & 0xffff);
+       fxsave->foo = env[5];
+       fxsave->fos = env[6];
+
+       to = (struct _fpxreg *) &fxsave->st_space[0];
+       from = &buf->_st[0];
+       for (i = 0; i < 8; i++, to++, from++) {
+               unsigned long *t = (unsigned long *)to;
+               unsigned long __user *f = (unsigned long __user *)from;
+
+               if (__get_user(*t, f) ||
+                   __get_user(*(t + 1), f + 1) ||
+                   __get_user(to->exponent, &from->exponent))
+                       return 1;
+       }
+       return 0;
 }
-#endif
 
-#ifdef CONFIG_MODE_TT
+extern int have_fpx_regs;
 
-/* These copy a sigcontext to/from userspace.  They copy the fpstate pointer,
- * blowing away the old, good one.  So, that value is saved, and then restored
- * after the sigcontext copy.  In copy_from, the variable holding the saved
- * fpstate pointer, and the sigcontext that it should be restored to are both
- * in the kernel, so we can just restore using an assignment.  In copy_to, the
- * saved pointer is in the kernel, but the sigcontext is in userspace, so we
- * copy_to_user it.
- */
-int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from,
-                        int fpsize)
+static int copy_sc_from_user(struct pt_regs *regs,
+                            struct sigcontext __user *from)
 {
-       struct _fpstate *to_fp;
-       struct _fpstate __user *from_fp;
-       unsigned long sigs;
+       struct sigcontext sc;
        int err;
 
-       to_fp = to->fpstate;
-       sigs = to->oldmask;
-       err = copy_from_user(to, from, sizeof(*to));
-       from_fp = to->fpstate;
-       to->oldmask = sigs;
-       to->fpstate = to_fp;
-       if(to_fp != NULL)
-               err |= copy_from_user(to_fp, from_fp, fpsize);
-       return(err);
+       err = copy_from_user(&sc, from, sizeof(sc));
+       if (err)
+               return err;
+
+       copy_sc(&regs->regs, &sc);
+       if (have_fpx_regs) {
+               struct user_fxsr_struct fpx;
+
+               err = copy_from_user(&fpx, &sc.fpstate->_fxsr_env[0],
+                                    sizeof(struct user_fxsr_struct));
+               if (err)
+                       return 1;
+
+               err = convert_fxsr_from_user(&fpx, sc.fpstate);
+               if (err)
+                       return 1;
+
+               err = restore_fpx_registers(userspace_pid[current_thread->cpu],
+                                           (unsigned long *) &fpx);
+               if (err < 0) {
+                       printk(KERN_ERR "copy_sc_from_user - "
+                              "restore_fpx_registers failed, errno = %d\n",
+                              -err);
+                       return 1;
+               }
+       }
+       else {
+               struct user_i387_struct fp;
+
+               err = copy_from_user(&fp, sc.fpstate,
+                                    sizeof(struct user_i387_struct));
+               if (err)
+                       return 1;
+
+               err = restore_fp_registers(userspace_pid[current_thread->cpu],
+                                          (unsigned long *) &fp);
+               if (err < 0) {
+                       printk(KERN_ERR "copy_sc_from_user - "
+                              "restore_fp_registers failed, errno = %d\n",
+                              -err);
+                       return 1;
+               }
+       }
+
+       return 0;
 }
 
-int copy_sc_to_user_tt(struct sigcontext __user *to, struct _fpstate __user *fp,
-                      struct sigcontext *from, int fpsize, unsigned long sp)
+static int copy_sc_to_user(struct sigcontext __user *to,
+                          struct _fpstate __user *to_fp, struct pt_regs *regs,
+                          unsigned long sp)
 {
-       struct _fpstate __user *to_fp;
-       struct _fpstate *from_fp;
+       struct sigcontext sc;
+       struct faultinfo * fi = &current->thread.arch.faultinfo;
        int err;
 
-       to_fp = (fp ? fp : (struct _fpstate __user *) (to + 1));
-       from_fp = from->fpstate;
-       err = copy_to_user(to, from, sizeof(*to));
+       sc.gs = REGS_GS(regs->regs.gp);
+       sc.fs = REGS_FS(regs->regs.gp);
+       sc.es = REGS_ES(regs->regs.gp);
+       sc.ds = REGS_DS(regs->regs.gp);
+       sc.di = REGS_EDI(regs->regs.gp);
+       sc.si = REGS_ESI(regs->regs.gp);
+       sc.bp = REGS_EBP(regs->regs.gp);
+       sc.sp = sp;
+       sc.bx = REGS_EBX(regs->regs.gp);
+       sc.dx = REGS_EDX(regs->regs.gp);
+       sc.cx = REGS_ECX(regs->regs.gp);
+       sc.ax = REGS_EAX(regs->regs.gp);
+       sc.ip = REGS_IP(regs->regs.gp);
+       sc.cs = REGS_CS(regs->regs.gp);
+       sc.flags = REGS_EFLAGS(regs->regs.gp);
+       sc.sp_at_signal = regs->regs.gp[UESP];
+       sc.ss = regs->regs.gp[SS];
+       sc.cr2 = fi->cr2;
+       sc.err = fi->error_code;
+       sc.trapno = fi->trap_no;
 
-       /* The SP in the sigcontext is the updated one for the signal
-        * delivery.  The sp passed in is the original, and this needs
-        * to be restored, so we stick it in separately.
-        */
-       err |= copy_to_user(&SC_SP(to), &sp, sizeof(sp));
+       to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
+       sc.fpstate = to_fp;
 
-       if(from_fp != NULL){
-               err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
-               err |= copy_to_user(to_fp, from_fp, fpsize);
+       if (have_fpx_regs) {
+               struct user_fxsr_struct fpx;
+
+               err = save_fpx_registers(userspace_pid[current_thread->cpu],
+                                        (unsigned long *) &fpx);
+               if (err < 0){
+                       printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
+                              "failed, errno = %d\n", err);
+                       return 1;
+               }
+
+               err = convert_fxsr_to_user(to_fp, &fpx);
+               if (err)
+                       return 1;
+
+               err |= __put_user(fpx.swd, &to_fp->status);
+               err |= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
+               if (err)
+                       return 1;
+
+               if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
+                                sizeof(struct user_fxsr_struct)))
+                       return 1;
        }
-       return err;
-}
-#endif
+       else {
+               struct user_i387_struct fp;
 
-static int copy_sc_from_user(struct pt_regs *to, void __user *from)
-{
-       int ret;
+               err = save_fp_registers(userspace_pid[current_thread->cpu],
+                                       (unsigned long *) &fp);
+               if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
+                       return 1;
+       }
 
-       ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
-                                              sizeof(struct _fpstate)),
-                         copy_sc_from_user_skas(to, from));
-       return(ret);
+       return copy_to_user(to, &sc, sizeof(sc));
 }
 
-static int copy_sc_to_user(struct sigcontext __user *to, struct _fpstate __user *fp,
-                          struct pt_regs *from, unsigned long sp)
-{
-       return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
-                                             sizeof(*fp), sp),
-                           copy_sc_to_user_skas(to, fp, from, sp)));
-}
-
-static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __user *fp,
-                                sigset_t *set, unsigned long sp)
+static int copy_ucontext_to_user(struct ucontext __user *uc,
+                                struct _fpstate __user *fp, sigset_t *set,
+                                unsigned long sp)
 {
        int err = 0;
 
@@ -185,7 +296,7 @@ static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __u
        err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
        err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
        err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
-       return(err);
+       return err;
 }
 
 struct sigframe
@@ -226,7 +337,7 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
                return 1;
 
        restorer = frame->retcode;
-       if(ka->sa.sa_flags & SA_RESTORER)
+       if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
 
        /* Update SP now because the page fault handler refuses to extend
@@ -258,7 +369,7 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
        err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
        err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
 
-       if(err)
+       if (err)
                goto err;
 
        PT_REGS_SP(regs) = (unsigned long) frame;
@@ -291,7 +402,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
                return 1;
 
        restorer = frame->retcode;
-       if(ka->sa.sa_flags & SA_RESTORER)
+       if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
 
        /* See comment above about why this is here */
@@ -316,7 +427,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
        err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
        err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
 
-       if(err)
+       if (err)
                goto err;
 
        PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
@@ -343,8 +454,8 @@ long sys_sigreturn(struct pt_regs regs)
        unsigned long __user *extramask = frame->extramask;
        int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
 
-       if(copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
-          copy_from_user(&set.sig[1], extramask, sig_size))
+       if (copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
+           copy_from_user(&set.sig[1], extramask, sig_size))
                goto segfault;
 
        sigdelsetmask(&set, ~_BLOCKABLE);
@@ -354,12 +465,12 @@ long sys_sigreturn(struct pt_regs regs)
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
 
-       if(copy_sc_from_user(&current->thread.regs, sc))
+       if (copy_sc_from_user(&current->thread.regs, sc))
                goto segfault;
 
        /* Avoid ERESTART handling */
        PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
-       return(PT_REGS_SYSCALL_RET(&current->thread.regs));
+       return PT_REGS_SYSCALL_RET(&current->thread.regs);
 
  segfault:
        force_sig(SIGSEGV, current);
@@ -369,12 +480,13 @@ long sys_sigreturn(struct pt_regs regs)
 long sys_rt_sigreturn(struct pt_regs regs)
 {
        unsigned long sp = PT_REGS_SP(&current->thread.regs);
-       struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (sp - 4);
+       struct rt_sigframe __user *frame =
+               (struct rt_sigframe __user *) (sp - 4);
        sigset_t set;
        struct ucontext __user *uc = &frame->uc;
        int sig_size = _NSIG_WORDS * sizeof(unsigned long);
 
-       if(copy_from_user(&set, &uc->uc_sigmask, sig_size))
+       if (copy_from_user(&set, &uc->uc_sigmask, sig_size))
                goto segfault;
 
        sigdelsetmask(&set, ~_BLOCKABLE);
@@ -384,25 +496,14 @@ long sys_rt_sigreturn(struct pt_regs regs)
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
 
-       if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
+       if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
                goto segfault;
 
        /* Avoid ERESTART handling */
        PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
-       return(PT_REGS_SYSCALL_RET(&current->thread.regs));
+       return PT_REGS_SYSCALL_RET(&current->thread.regs);
 
  segfault:
        force_sig(SIGSEGV, current);
        return 0;
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */