Merge commit 'linus/master' into tracing/kprobes

[mv-sheeva.git] / arch / x86 / kernel / ptrace.c

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 8d7d5c9c1be31058b651101503edc68028e62351..c4f76d275ee4cda38bed14268a4ac3b6f04d7436 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -49,6 +49,118 @@ enum x86_regset {
        REGSET_IOPERM32,
 };
 
+struct pt_regs_offset {
+       const char *name;
+       int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+#ifdef CONFIG_X86_64
+       REG_OFFSET_NAME(r15),
+       REG_OFFSET_NAME(r14),
+       REG_OFFSET_NAME(r13),
+       REG_OFFSET_NAME(r12),
+       REG_OFFSET_NAME(r11),
+       REG_OFFSET_NAME(r10),
+       REG_OFFSET_NAME(r9),
+       REG_OFFSET_NAME(r8),
+#endif
+       REG_OFFSET_NAME(bx),
+       REG_OFFSET_NAME(cx),
+       REG_OFFSET_NAME(dx),
+       REG_OFFSET_NAME(si),
+       REG_OFFSET_NAME(di),
+       REG_OFFSET_NAME(bp),
+       REG_OFFSET_NAME(ax),
+#ifdef CONFIG_X86_32
+       REG_OFFSET_NAME(ds),
+       REG_OFFSET_NAME(es),
+       REG_OFFSET_NAME(fs),
+       REG_OFFSET_NAME(gs),
+#endif
+       REG_OFFSET_NAME(orig_ax),
+       REG_OFFSET_NAME(ip),
+       REG_OFFSET_NAME(cs),
+       REG_OFFSET_NAME(flags),
+       REG_OFFSET_NAME(sp),
+       REG_OFFSET_NAME(ss),
+       REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name:      the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+       const struct pt_regs_offset *roff;
+       for (roff = regoffset_table; roff->name != NULL; roff++)
+               if (!strcmp(roff->name, name))
+                       return roff->offset;
+       return -EINVAL;
+}
+
+/**
+ * regs_query_register_name() - query register name from its offset
+ * @offset:    the offset of a register in struct pt_regs.
+ *
+ * regs_query_register_name() returns the name of a register from its
+ * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
+ */
+const char *regs_query_register_name(unsigned int offset)
+{
+       const struct pt_regs_offset *roff;
+       for (roff = regoffset_table; roff->name != NULL; roff++)
+               if (roff->offset == offset)
+                       return roff->name;
+       return NULL;
+}
+
+static const int arg_offs_table[] = {
+#ifdef CONFIG_X86_32
+       [0] = offsetof(struct pt_regs, ax),
+       [1] = offsetof(struct pt_regs, dx),
+       [2] = offsetof(struct pt_regs, cx)
+#else /* CONFIG_X86_64 */
+       [0] = offsetof(struct pt_regs, di),
+       [1] = offsetof(struct pt_regs, si),
+       [2] = offsetof(struct pt_regs, dx),
+       [3] = offsetof(struct pt_regs, cx),
+       [4] = offsetof(struct pt_regs, r8),
+       [5] = offsetof(struct pt_regs, r9)
+#endif
+};
+
+/**
+ * regs_get_argument_nth() - get Nth argument at function call
+ * @regs:      pt_regs which contains registers at function entry.
+ * @n:         argument number.
+ *
+ * regs_get_argument_nth() returns @n th argument of a function call.
+ * Since usually the kernel stack will be changed right after function entry,
+ * you must use this at function entry. If the @n th entry is NOT in the
+ * kernel stack or pt_regs, this returns 0.
+ */
+unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n)
+{
+       if (n < ARRAY_SIZE(arg_offs_table))
+               return *(unsigned long *)((char *)regs + arg_offs_table[n]);
+       else {
+               /*
+                * The typical case: arg n is on the stack.
+                * (Note: stack[0] = return address, so skip it)
+                */
+               n -= ARRAY_SIZE(arg_offs_table);
+               return regs_get_kernel_stack_nth(regs, 1 + n);
+       }
+}
+
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
@@ -325,16 +437,6 @@ static int putreg(struct task_struct *child,
                return set_flags(child, value);
 
 #ifdef CONFIG_X86_64
-       /*
-        * Orig_ax is really just a flag with small positive and
-        * negative values, so make sure to always sign-extend it
-        * from 32 bits so that it works correctly regardless of
-        * whether we come from a 32-bit environment or not.
-        */
-       case offsetof(struct user_regs_struct, orig_ax):
-               value = (long) (s32) value;
-               break;
-
        case offsetof(struct user_regs_struct,fs_base):
                if (value >= TASK_SIZE_OF(child))
                        return -EIO;
@@ -1126,10 +1228,15 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 
        case offsetof(struct user32, regs.orig_eax):
                /*
-                * Sign-extend the value so that orig_eax = -1
-                * causes (long)orig_ax < 0 tests to fire correctly.
+                * A 32-bit debugger setting orig_eax means to restore
+                * the state of the task restarting a 32-bit syscall.
+                * Make sure we interpret the -ERESTART* codes correctly
+                * in case the task is not actually still sitting at the
+                * exit from a 32-bit syscall with TS_COMPAT still set.
                 */
-               regs->orig_ax = (long) (s32) value;
+               regs->orig_ax = value;
+               if (syscall_get_nr(child, regs) >= 0)
+                       task_thread_info(child)->status |= TS_COMPAT;
                break;
 
        case offsetof(struct user32, regs.eflags):