gdb/patches/gdb-6.3-ppc64syscall-20040622.patch

   1 2004-06-22  Andrew Cagney  <cagney@gnu.org>
   2
   3         * rs6000-tdep.c (struct rs6000_framedata): Add field "func_start".
   4         (skip_prologue): Delete local variable "orig_pc", use
   5         "func_start".  Add local variable "num_skip_linux_syscall_insn",
   6         use to skip over first half of a GNU/Linux syscall and update
   7         "func_start".
   8
   9 Index: gdb-7.2.50.20110117/gdb/rs6000-tdep.c
  10 ===================================================================
  11 --- gdb-7.2.50.20110117.orig/gdb/rs6000-tdep.c  2011-01-11 20:23:02.000000000 +0100
  12 +++ gdb-7.2.50.20110117/gdb/rs6000-tdep.c       2011-01-17 15:48:19.000000000 +0100
  13 @@ -126,6 +126,7 @@ static const char *powerpc_vector_abi_st
  14
  15  struct rs6000_framedata
  16    {
  17 +    CORE_ADDR func_start;      /* True function start.  */
  18      int offset;                        /* total size of frame --- the distance
  19                                    by which we decrement sp to allocate
  20                                    the frame */
  21 @@ -1496,7 +1497,6 @@ static CORE_ADDR
  22  skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
  23                struct rs6000_framedata *fdata)
  24  {
  25 -  CORE_ADDR orig_pc = pc;
  26    CORE_ADDR last_prologue_pc = pc;
  27    CORE_ADDR li_found_pc = 0;
  28    gdb_byte buf[4];
  29 @@ -1514,12 +1514,14 @@ skip_prologue (struct gdbarch *gdbarch,
  30    int minimal_toc_loaded = 0;
  31    int prev_insn_was_prologue_insn = 1;
  32    int num_skip_non_prologue_insns = 0;
  33 +  int num_skip_ppc64_gnu_linux_syscall_insn = 0;
  34    int r0_contains_arg = 0;
  35    const struct bfd_arch_info *arch_info = gdbarch_bfd_arch_info (gdbarch);
  36    struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  37    enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  38
  39    memset (fdata, 0, sizeof (struct rs6000_framedata));
  40 +  fdata->func_start = pc;
  41    fdata->saved_gpr = -1;
  42    fdata->saved_fpr = -1;
  43    fdata->saved_vr = -1;
  44 @@ -1553,6 +1555,55 @@ skip_prologue (struct gdbarch *gdbarch,
  45         break;
  46        op = extract_unsigned_integer (buf, 4, byte_order);
  47
  48 +      /* A PPC64 GNU/Linux system call function is split into two
  49 +        sub-functions: a non-threaded fast-path (__NAME_nocancel)
  50 +        which does not use a frame; and a threaded slow-path
  51 +        (Lpseudo_cancel) that does create a frame.  Ref:
  52 +        nptl/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h
  53 +
  54 +        *INDENT-OFF*
  55 +        NAME:
  56 +               SINGLE_THREAD_P
  57 +               bne- .Lpseudo_cancel
  58 +        __NAME_nocancel:
  59 +               li r0,162
  60 +               sc
  61 +               bnslr+
  62 +               b 0x7fe014ef64 <.__syscall_error>
  63 +        Lpseudo_cancel:
  64 +               stdu r1,-128(r1)
  65 +               ...
  66 +        *INDENT-ON*
  67 +
  68 +        Unfortunatly, because the latter case uses a local label (not
  69 +        in the symbol table) a PC in "Lpseudo_cancel" appears to be
  70 +        in "__NAME_nocancel".  The following code recognizes this,
  71 +        adjusting FUNC_START to point to where "Lpseudo_cancel"
  72 +        should be, and parsing the prologue sequence as if
  73 +        "Lpseudo_cancel" was the entry point.  */
  74 +
  75 +      if (((op & 0xffff0000) == 0x38000000 /* li r0,N */
  76 +          && pc == fdata->func_start + 0
  77 +          && num_skip_ppc64_gnu_linux_syscall_insn == 0)
  78 +         || (op == 0x44000002 /* sc */
  79 +             && pc == fdata->func_start + 4
  80 +             && num_skip_ppc64_gnu_linux_syscall_insn == 1)
  81 +         || (op == 0x4ca30020 /* bnslr+ */
  82 +             && pc == fdata->func_start + 8
  83 +             && num_skip_ppc64_gnu_linux_syscall_insn == 2))
  84 +       {
  85 +         num_skip_ppc64_gnu_linux_syscall_insn++;
  86 +         continue;
  87 +       }
  88 +      else if ((op & 0xfc000003) == 0x48000000 /* b __syscall_error */
  89 +              && pc == fdata->func_start + 12
  90 +              && num_skip_ppc64_gnu_linux_syscall_insn == 3)
  91 +       {
  92 +         num_skip_ppc64_gnu_linux_syscall_insn = -1;
  93 +         fdata->func_start = pc;
  94 +         continue;
  95 +       }
  96 +
  97        if ((op & 0xfc1fffff) == 0x7c0802a6)
  98         {                       /* mflr Rx */
  99           /* Since shared library / PIC code, which needs to get its
 100 @@ -1734,9 +1785,9 @@ skip_prologue (struct gdbarch *gdbarch,
 101              we have no line table information or the line info tells
 102              us that the subroutine call is not part of the line
 103              associated with the prologue.  */
 104 -         if ((pc - orig_pc) > 8)
 105 +         if ((pc - fdata->func_start) > 8)
 106             {
 107 -             struct symtab_and_line prologue_sal = find_pc_line (orig_pc, 0);
 108 +             struct symtab_and_line prologue_sal = find_pc_line (fdata->func_start, 0);
 109               struct symtab_and_line this_sal = find_pc_line (pc, 0);
 110
 111               if ((prologue_sal.line == 0)