uml: ptrace floating point fixes

Handle floating point state better in ptrace.  The code now correctly
distinguishes between PTRACE_[GS]ETFPREGS and PTRACE_[GS]ETFPXREGS.  The FPX
requests get handed off to arch-specific code because that's not generic.

get_fpregs, set_fpregs, set_fpregs, and set_fpxregs needed real
implementations.

Something here exposed a missing include in asm/page.h, which needed
linux/types.h in order to get gfp_t, so that's fixed here.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 107 insertions, 55 deletions

diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index db55a017e9b9..2511f9199417 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -143,22 +143,14 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 #endif
 #ifdef PTRACE_GETFPREGS
         case PTRACE_GETFPREGS: /* Get the child FPU state. */
-                ret = get_fpregs(data, child);
+                ret = get_fpregs((struct user_i387_struct __user *) data,
+                                 child);
                 break;
 #endif
 #ifdef PTRACE_SETFPREGS
         case PTRACE_SETFPREGS: /* Set the child FPU state. */
-                ret = set_fpregs(data, child);
-                break;
-#endif
-#ifdef PTRACE_GETFPXREGS
-        case PTRACE_GETFPXREGS: /* Get the child FPU state. */
-                ret = get_fpxregs(data, child);
-                break;
-#endif
-#ifdef PTRACE_SETFPXREGS
-        case PTRACE_SETFPXREGS: /* Set the child FPU state. */
-                ret = set_fpxregs(data, child);
+                ret = set_fpregs((struct user_i387_struct __user *) data,
+                                 child);
                 break;
 #endif
         case PTRACE_GET_THREAD_AREA:
@@ -227,6 +219,8 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 #endif
         default:
                 ret = ptrace_request(child, request, addr, data);
+                if (ret == -EIO)
+                        ret = subarch_ptrace(child, request, addr, data);
                 break;
         }
 
diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index cb899dd1c6b5..659011df1e9a 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -6,6 +6,7 @@
 #include "linux/mm.h"
 #include "linux/sched.h"
 #include "asm/uaccess.h"
+#include "skas.h"
 
 extern int arch_switch_tls(struct task_struct *from, struct task_struct *to);
 
@@ -144,48 +145,64 @@ int peek_user(struct task_struct *child, long addr, long data)
         return put_user(tmp, (unsigned long __user *) data);
 }
 
-static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
-                                       struct pt_regs *regs)
+int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 {
-        return 0;
-}
+        int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_FP_SIZE];
 
-static inline int convert_fxsr_from_user(struct pt_regs *regs,
-                                         struct _fpstate __user *buf)
-{
-        return 0;
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        err = save_fp_registers(userspace_pid[cpu], fpregs);
+        if (err)
+                return err;
+
+        n = copy_to_user((void *) buf, fpregs, sizeof(fpregs));
+        if(n > 0)
+                return -EFAULT;
+
+        return n;
 }
 
-int get_fpregs(unsigned long buf, struct task_struct *child)
+int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 {
-        int err;
+        int n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_FP_SIZE];
 
-        err = convert_fxsr_to_user((struct _fpstate __user *) buf,
-                                   &child->thread.regs);
-        if (err)
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        n = copy_from_user(fpregs, (void *) buf, sizeof(fpregs));
+        if (n > 0)
                 return -EFAULT;
-        return 0;
+
+        return restore_fp_registers(userspace_pid[cpu], fpregs);
 }
 
-int set_fpregs(unsigned long buf, struct task_struct *child)
+int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
 {
-        int err;
+        int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_XFP_SIZE];
 
-        err = convert_fxsr_from_user(&child->thread.regs,
-                                     (struct _fpstate __user *) buf);
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        err = save_fpx_registers(userspace_pid[cpu], fpregs);
         if (err)
+                return err;
+
+        n = copy_to_user((void *) buf, fpregs, sizeof(fpregs));
+        if(n > 0)
                 return -EFAULT;
-        return 0;
-}
 
-int get_fpxregs(unsigned long buf, struct task_struct *tsk)
-{
-        return 0;
+        return n;
 }
 
-int set_fpxregs(unsigned long buf, struct task_struct *tsk)
+int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
 {
-        return 0;
+        int n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_XFP_SIZE];
+
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        n = copy_from_user(fpregs, (void *) buf, sizeof(fpregs));
+        if (n > 0)
+                return -EFAULT;
+
+        return restore_fpx_registers(userspace_pid[cpu], fpregs);
 }
 
 #ifdef notdef
@@ -209,3 +226,9 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 {
         return 1;
 }
+
+long subarch_ptrace(struct task_struct *child, long request, long addr,
+                    long data)
+{
+        return -EIO;
+}
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index 1970d78aa528..b9032992a997 100644
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -156,28 +156,53 @@ int is_syscall(unsigned long addr)
         return(instr == 0x050f);
 }
 
-int get_fpregs(unsigned long buf, struct task_struct *child)
+int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 {
-        panic("get_fpregs");
-        return(0);
-}
+        int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_FP_SIZE];
 
-int set_fpregs(unsigned long buf, struct task_struct *child)
-{
-        panic("set_fpregs");
-        return(0);
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        err = save_fp_registers(userspace_pid[cpu], fpregs);
+        if (err)
+                return err;
+
+        n = copy_to_user((void *) buf, fpregs, sizeof(fpregs));
+        if(n > 0)
+                return -EFAULT;
+
+        return n;
 }
 
-int get_fpxregs(unsigned long buf, struct task_struct *tsk)
+int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 {
-        panic("get_fpxregs");
-        return(0);
+        int n, cpu = ((struct thread_info *) child->stack)->cpu;
+        long fpregs[HOST_FP_SIZE];
+
+        BUG_ON(sizeof(*buf) != sizeof(fpregs));
+        n = copy_from_user(fpregs, (void *) buf, sizeof(fpregs));
+        if (n > 0)
+                return -EFAULT;
+
+        return restore_fp_registers(userspace_pid[cpu], fpregs);
 }
 
-int set_fpxregs(unsigned long buf, struct task_struct *tsk)
+long subarch_ptrace(struct task_struct *child, long request, long addr,
+                    long data)
 {
-        panic("set_fxpregs");
-        return(0);
+        int ret = -EIO;
+
+        switch (request) {
+        case PTRACE_GETFPXREGS: /* Get the child FPU state. */
+                ret = get_fpregs((struct user_i387_struct __user *) data,
+                                 child);
+                break;
+        case PTRACE_SETFPXREGS: /* Set the child FPU state. */
+                ret = set_fpregs((struct user_i387_struct __user *) data,
+                                 child);
+                break;
+        }
+
+        return ret;
 }
 
 /*
diff --git a/include/asm-um/page.h b/include/asm-um/page.h
index 8e310d81e5b4..4b424c75fca5 100644
--- a/include/asm-um/page.h
+++ b/include/asm-um/page.h
@@ -9,6 +9,7 @@
 
 struct page;
 
+#include <linux/types.h>
 #include <asm/vm-flags.h>
 
 /* PAGE_SHIFT determines the page size */
diff --git a/include/asm-um/ptrace-generic.h b/include/asm-um/ptrace-generic.h
index 919581d713bd..6aefcd32fc61 100644
--- a/include/asm-um/ptrace-generic.h
+++ b/include/asm-um/ptrace-generic.h
@@ -9,6 +9,7 @@
 #ifndef __ASSEMBLY__
 
 #include "asm/arch/ptrace-abi.h"
+#include <asm/user.h>
 #include "sysdep/ptrace.h"
 
 struct pt_regs {
@@ -35,12 +36,14 @@ struct pt_regs {
 
 struct task_struct;
 
+extern long subarch_ptrace(struct task_struct *child, long request, long addr,
+                           long data);
 extern unsigned long getreg(struct task_struct *child, int regno);
 extern int putreg(struct task_struct *child, int regno, unsigned long value);
-extern int get_fpregs(unsigned long buf, struct task_struct *child);
-extern int set_fpregs(unsigned long buf, struct task_struct *child);
-extern int get_fpxregs(unsigned long buf, struct task_struct *child);
-extern int set_fpxregs(unsigned long buf, struct task_struct *tsk);
+extern int get_fpregs(struct user_i387_struct __user *buf,
+                      struct task_struct *child);
+extern int set_fpregs(struct user_i387_struct __user *buf,
+                      struct task_struct *child);
 
 extern void show_regs(struct pt_regs *regs);
 
diff --git a/include/asm-um/ptrace-i386.h b/include/asm-um/ptrace-i386.h
index 65102c883440..b2d24c5ea2c3 100644
--- a/include/asm-um/ptrace-i386.h
+++ b/include/asm-um/ptrace-i386.h
@@ -10,6 +10,7 @@
 
 #include "linux/compiler.h"
 #include "asm/ptrace-generic.h"
+#include <asm/user.h>
 #include "sysdep/ptrace.h"
 
 #define PT_REGS_EAX(r) UPT_EAX(&(r)->regs)
@@ -45,6 +46,11 @@
  */
 struct user_desc;
 
+extern int get_fpxregs(struct user_fxsr_struct __user *buf,
+                       struct task_struct *child);
+extern int set_fpxregs(struct user_fxsr_struct __user *buf,
+                       struct task_struct *tsk);
+
 extern int ptrace_get_thread_area(struct task_struct *child, int idx,
                                   struct user_desc __user *user_desc);