gdb/gdb-6.3-ppc64syscall-20040622.patch
2004-12-02 18:30:25 +00:00

113 lines
3.9 KiB
Diff

2004-06-22 Andrew Cagney <cagney@gnu.org>
* rs6000-tdep.c (struct rs6000_framedata): Add field "func_start".
(skip_prologue): Delete local variable "orig_pc", use
"func_start". Add local variable "num_skip_linux_syscall_insn",
use to skip over first half of a GNU/Linux syscall and update
"func_start".
Index: ./gdb/rs6000-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/rs6000-tdep.c,v
retrieving revision 1.215
diff -p -u -r1.215 rs6000-tdep.c
--- ./gdb/rs6000-tdep.c 20 Jun 2004 17:18:06 -0000 1.215
+++ ./gdb/rs6000-tdep.c 22 Jun 2004 19:06:46 -0000
@@ -71,6 +71,7 @@
struct rs6000_framedata
{
+ CORE_ADDR func_start; /* True function start. */
int offset; /* total size of frame --- the distance
by which we decrement sp to allocate
the frame */
@@ -694,7 +695,6 @@ store_param_on_stack_p (unsigned long op
static CORE_ADDR
skip_prologue (CORE_ADDR pc, CORE_ADDR lim_pc, struct rs6000_framedata *fdata)
{
- CORE_ADDR orig_pc = pc;
CORE_ADDR last_prologue_pc = pc;
CORE_ADDR li_found_pc = 0;
char buf[4];
@@ -712,6 +712,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
int minimal_toc_loaded = 0;
int prev_insn_was_prologue_insn = 1;
int num_skip_non_prologue_insns = 0;
+ int num_skip_ppc64_gnu_linux_syscall_insn = 0;
int r0_contains_arg = 0;
const struct bfd_arch_info *arch_info = gdbarch_bfd_arch_info (current_gdbarch);
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
@@ -732,6 +733,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
lim_pc = refine_prologue_limit (pc, lim_pc);
memset (fdata, 0, sizeof (struct rs6000_framedata));
+ fdata->func_start = pc;
fdata->saved_gpr = -1;
fdata->saved_fpr = -1;
fdata->saved_vr = -1;
@@ -760,6 +762,55 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
break;
op = extract_signed_integer (buf, 4);
+ /* A PPC64 GNU/Linux system call function is split into two
+ sub-functions: a non-threaded fast-path (__NAME_nocancel)
+ which does not use a frame; and a threaded slow-path
+ (Lpseudo_cancel) that does create a frame. Ref:
+ nptl/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep-cancel.h
+
+ *INDENT-OFF*
+ NAME:
+ SINGLE_THREAD_P
+ bne- .Lpseudo_cancel
+ __NAME_nocancel:
+ li r0,162
+ sc
+ bnslr+
+ b 0x7fe014ef64 <.__syscall_error>
+ Lpseudo_cancel:
+ stdu r1,-128(r1)
+ ...
+ *INDENT-ON*
+
+ Unfortunatly, because the latter case uses a local label (not
+ in the symbol table) a PC in "Lpseudo_cancel" appears to be
+ in "__NAME_nocancel". The following code recognizes this,
+ adjusting FUNC_START to point to where "Lpseudo_cancel"
+ should be, and parsing the prologue sequence as if
+ "Lpseudo_cancel" was the entry point. */
+
+ if (((op & 0xffff0000) == 0x38000000 /* li r0,N */
+ && pc == fdata->func_start + 0
+ && num_skip_ppc64_gnu_linux_syscall_insn == 0)
+ || (op == 0x44000002 /* sc */
+ && pc == fdata->func_start + 4
+ && num_skip_ppc64_gnu_linux_syscall_insn == 1)
+ || (op == 0x4ca30020 /* bnslr+ */
+ && pc == fdata->func_start + 8
+ && num_skip_ppc64_gnu_linux_syscall_insn == 2))
+ {
+ num_skip_ppc64_gnu_linux_syscall_insn++;
+ continue;
+ }
+ else if ((op & 0xfc000003) == 0x48000000 /* b __syscall_error */
+ && pc == fdata->func_start + 12
+ && num_skip_ppc64_gnu_linux_syscall_insn == 3)
+ {
+ num_skip_ppc64_gnu_linux_syscall_insn = -1;
+ fdata->func_start = pc;
+ continue;
+ }
+
if ((op & 0xfc1fffff) == 0x7c0802a6)
{ /* mflr Rx */
/* Since shared library / PIC code, which needs to get its
@@ -913,7 +964,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
fdata->frameless = 0;
/* Don't skip over the subroutine call if it is not within
the first three instructions of the prologue. */
- if ((pc - orig_pc) > 8)
+ if ((pc - fdata->func_start) > 8)
break;
op = read_memory_integer (pc + 4, 4);