Merge branch 'x86-ptrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-ptrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, ptrace: Remove set_stopped_child_used_math() in [x]fpregs_set
  x86, ptrace: Simplify xstateregs_get()
  ptrace: Fix ptrace_regset() comments and diagnose errors specifically
  parisc: Disable CONFIG_HAVE_ARCH_TRACEHOOK
  ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET
  x86, ptrace: regset extensions to support xstate

3 files changed, 100 insertions, 6 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index f2f8540a7f3..c01a2b846d4 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -164,6 +164,11 @@ int init_fpu(struct task_struct *tsk)
         return 0;
 }
 
+/*
+ * The xstateregs_active() routine is the same as the fpregs_active() routine,
+ * as the "regset->n" for the xstate regset will be updated based on the feature
+ * capabilites supported by the xsave.
+ */
 int fpregs_active(struct task_struct *target, const struct user_regset *regset)
 {
         return tsk_used_math(target) ? regset->n : 0;
@@ -204,8 +209,6 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
         if (ret)
                 return ret;
 
-        set_stopped_child_used_math(target);
-
         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                                  &target->thread.xstate->fxsave, 0, -1);
 
@@ -224,6 +227,68 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
         return ret;
 }
 
+int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
+                unsigned int pos, unsigned int count,
+                void *kbuf, void __user *ubuf)
+{
+        int ret;
+
+        if (!cpu_has_xsave)
+                return -ENODEV;
+
+        ret = init_fpu(target);
+        if (ret)
+                return ret;
+
+        /*
+         * Copy the 48bytes defined by the software first into the xstate
+         * memory layout in the thread struct, so that we can copy the entire
+         * xstateregs to the user using one user_regset_copyout().
+         */
+        memcpy(&target->thread.xstate->fxsave.sw_reserved,
+               xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
+
+        /*
+         * Copy the xstate memory layout.
+         */
+        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  &target->thread.xstate->xsave, 0, -1);
+        return ret;
+}
+
+int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
+                  unsigned int pos, unsigned int count,
+                  const void *kbuf, const void __user *ubuf)
+{
+        int ret;
+        struct xsave_hdr_struct *xsave_hdr;
+
+        if (!cpu_has_xsave)
+                return -ENODEV;
+
+        ret = init_fpu(target);
+        if (ret)
+                return ret;
+
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 &target->thread.xstate->xsave, 0, -1);
+
+        /*
+         * mxcsr reserved bits must be masked to zero for security reasons.
+         */
+        target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+
+        xsave_hdr = &target->thread.xstate->xsave.xsave_hdr;
+
+        xsave_hdr->xstate_bv &= pcntxt_mask;
+        /*
+         * These bits must be zero.
+         */
+        xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
+
+        return ret;
+}
+
 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 
 /*
@@ -404,8 +469,6 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
         if (ret)
                 return ret;
 
-        set_stopped_child_used_math(target);
-
         if (!HAVE_HWFP)
                 return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
 
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index d03146f71b2..2d96aab82a4 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -48,6 +48,7 @@ enum x86_regset {
         REGSET_FP,
         REGSET_XFP,
         REGSET_IOPERM64 = REGSET_XFP,
+        REGSET_XSTATE,
         REGSET_TLS,
         REGSET_IOPERM32,
 };
@@ -1563,7 +1564,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 #ifdef CONFIG_X86_64
 
-static const struct user_regset x86_64_regsets[] = {
+static struct user_regset x86_64_regsets[] __read_mostly = {
         [REGSET_GENERAL] = {
                 .core_note_type = NT_PRSTATUS,
                 .n = sizeof(struct user_regs_struct) / sizeof(long),
@@ -1576,6 +1577,12 @@ static const struct user_regset x86_64_regsets[] = {
                 .size = sizeof(long), .align = sizeof(long),
                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
         },
+        [REGSET_XSTATE] = {
+                .core_note_type = NT_X86_XSTATE,
+                .size = sizeof(u64), .align = sizeof(u64),
+                .active = xstateregs_active, .get = xstateregs_get,
+                .set = xstateregs_set
+        },
         [REGSET_IOPERM64] = {
                 .core_note_type = NT_386_IOPERM,
                 .n = IO_BITMAP_LONGS,
@@ -1601,7 +1608,7 @@ static const struct user_regset_view user_x86_64_view = {
 #endif  /* CONFIG_X86_64 */
 
 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
-static const struct user_regset x86_32_regsets[] = {
+static struct user_regset x86_32_regsets[] __read_mostly = {
         [REGSET_GENERAL] = {
                 .core_note_type = NT_PRSTATUS,
                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
@@ -1620,6 +1627,12 @@ static const struct user_regset x86_32_regsets[] = {
                 .size = sizeof(u32), .align = sizeof(u32),
                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
         },
+        [REGSET_XSTATE] = {
+                .core_note_type = NT_X86_XSTATE,
+                .size = sizeof(u64), .align = sizeof(u64),
+                .active = xstateregs_active, .get = xstateregs_get,
+                .set = xstateregs_set
+        },
         [REGSET_TLS] = {
                 .core_note_type = NT_386_TLS,
                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
@@ -1642,6 +1655,23 @@ static const struct user_regset_view user_x86_32_view = {
 };
 #endif
 
+/*
+ * This represents bytes 464..511 in the memory layout exported through
+ * the REGSET_XSTATE interface.
+ */
+u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
+
+void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
+{
+#ifdef CONFIG_X86_64
+        x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
+#endif
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+        x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
+#endif
+        xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
+}
+
 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 {
 #ifdef CONFIG_IA32_EMULATION
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index c5ee17e8c6d..782c3a362ec 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -337,6 +337,7 @@ void __ref xsave_cntxt_init(void)
         cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
         xstate_size = ebx;
 
+        update_regset_xstate_info(xstate_size, pcntxt_mask);
         prepare_fx_sw_frame();
 
         setup_xstate_init();