fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / arch / x86_64 / kernel / ptrace.c

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index 280bc88..57bf883 100644 (file)
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -119,17 +119,17 @@ unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *r
        return addr;
 }
 
-static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
+static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
 {
        int i, copied;
-       unsigned char opcode[16];
+       unsigned char opcode[15];
        unsigned long addr = convert_rip_to_linear(child, regs);
 
        copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
        for (i = 0; i < copied; i++) {
                switch (opcode[i]) {
-               /* popf */
-               case 0x9d:
+               /* popf and iret */
+               case 0x9d: case 0xcf:
                        return 1;
 
                        /* CHECKME: 64 65 */
@@ -141,14 +141,17 @@ static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
                case 0x26: case 0x2e:
                case 0x36: case 0x3e:
                case 0x64: case 0x65:
-               case 0xf0: case 0xf2: case 0xf3:
+               case 0xf2: case 0xf3:
                        continue;
 
-               /* REX prefixes */
                case 0x40 ... 0x4f:
+                       if (regs->cs != __USER_CS)
+                               /* 32-bit mode: register increment */
+                               return 0;
+                       /* 64-bit mode: REX prefix */
                        continue;
 
-                       /* CHECKME: f0, f2, f3 */
+                       /* CHECKME: f2, f3 */
 
                /*
                 * pushf: NOTE! We should probably not let
@@ -189,10 +192,8 @@ void tracehook_enable_single_step(struct task_struct *child)
         * ..but if TF is changed by the instruction we will trace,
         * don't mark it as being "us" that set it, so that we
         * won't clear it by hand later.
-        *
-        * AK: this is not enough, LAHF and IRET can change TF in user space too.
         */
-       if (is_at_popf(child, regs))
+       if (is_setting_trap_flag(child, regs))
                return;
 
        set_tsk_thread_flag(child, TIF_FORCED_TF);
@@ -424,6 +425,7 @@ dbregs_set(struct task_struct *target,
           unsigned int pos, unsigned int count,
           const void *kbuf, const void __user *ubuf)
 {
+
        unsigned long maxaddr = TASK_SIZE_OF(target);
        maxaddr -= test_tsk_thread_flag(target, TIF_IA32) ? 3 : 7;
 
@@ -487,6 +489,10 @@ dbregs_set(struct task_struct *target,
                                if ((0x5554 >> ((val >> (16 + 4*i)) & 0xf))
                                    & 1)
                                        return -EIO;
+                       if (val)
+                               set_tsk_thread_flag(target, TIF_DEBUG);
+                       else
+                               clear_tsk_thread_flag(target, TIF_DEBUG);
                        SET_DBREG(7);
                        break;
 #undef SET_DBREG
@@ -512,7 +518,7 @@ fpregs_get(struct task_struct *target,
        if (tsk_used_math(target)) {
                if (target == current)
                        unlazy_fpu(target);
-       }
+       } 
        else
                init_fpu(target);
 
@@ -669,8 +675,7 @@ static const struct utrace_regset native_regsets[] = {
 
 const struct utrace_regset_view utrace_x86_64_native = {
        .name = "x86-64", .e_machine = EM_X86_64,
-       .regsets = native_regsets,
-       .n = sizeof native_regsets / sizeof native_regsets[0],
+       .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 };
 EXPORT_SYMBOL_GPL(utrace_x86_64_native);
 
@@ -678,16 +683,16 @@ EXPORT_SYMBOL_GPL(utrace_x86_64_native);
 #ifdef CONFIG_PTRACE
 static const struct ptrace_layout_segment x86_64_uarea[] = {
        {0, sizeof(struct user_regs_struct), 0, 0},
+       {sizeof(struct user_regs_struct),
+        offsetof(struct user, u_debugreg[0]), -1, 0},
        {offsetof(struct user, u_debugreg[0]),
-        offsetof(struct user, u_debugreg[4]), 3, 0},
-       {offsetof(struct user, u_debugreg[6]),
-        offsetof(struct user, u_debugreg[8]), 3, 6 * sizeof(long)},
+        offsetof(struct user, u_debugreg[8]), 3, 0},
        {0, 0, -1, 0}
 };
 
-fastcall int arch_ptrace(long *req, struct task_struct *child,
-                        struct utrace_attached_engine *engine,
-                        unsigned long addr, unsigned long data, long *val)
+int arch_ptrace(long *req, struct task_struct *child,
+               struct utrace_attached_engine *engine,
+               unsigned long addr, unsigned long data, long *val)
 {
        switch (*req) {
        case PTRACE_PEEKUSR: