x86/ptrace: Fix regs_get_argument_nth() to add correct offset

[pandora-kernel.git] / arch / x86 / kernel / ptrace.c

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 09ecbde..caffb68 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -35,10 +35,11 @@
 #include <asm/proto.h>
 #include <asm/ds.h>
 
-#include <trace/syscall.h>
-
 #include "tls.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
 enum x86_regset {
        REGSET_GENERAL,
        REGSET_FP,
@@ -48,6 +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.
@@ -1497,8 +1610,8 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs)
            tracehook_report_syscall_entry(regs))
                ret = -1L;
 
-       if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
-               ftrace_syscall_enter(regs);
+       if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+               trace_sys_enter(regs, regs->orig_ax);
 
        if (unlikely(current->audit_context)) {
                if (IS_IA32)
@@ -1523,8 +1636,8 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
        if (unlikely(current->audit_context))
                audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
 
-       if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
-               ftrace_syscall_exit(regs);
+       if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+               trace_sys_exit(regs, regs->ax);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE))
                tracehook_report_syscall_exit(regs, 0);