/* Target-dependent code for GNU/Linux on Alpha.
- Copyright 2002 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2007, 2008, 2009 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-#include "gdbcore.h"
-#include "value.h"
+#include "frame.h"
+#include "gdb_assert.h"
+#include "gdb_string.h"
+#include "osabi.h"
+#include "solib-svr4.h"
+#include "symtab.h"
+#include "regset.h"
+#include "regcache.h"
#include "alpha-tdep.h"
-/* Under GNU/Linux, signal handler invocations can be identified by the
- designated code sequence that is used to return from a signal
+/* Under GNU/Linux, signal handler invocations can be identified by
+ the designated code sequence that is used to return from a signal
handler. In particular, the return address of a signal handler
- points to the following sequence (the first instruction is quadword
- aligned):
-
- bis $30,$30,$16
- addq $31,0x67,$0
- call_pal callsys
-
- Each instruction has a unique encoding, so we simply attempt to
- match the instruction the pc is pointing to with any of the above
- instructions. If there is a hit, we know the offset to the start
- of the designated sequence and can then check whether we really are
- executing in a designated sequence. If not, -1 is returned,
- otherwise the offset from the start of the desingated sequence is
- returned.
-
- There is a slight chance of false hits: code could jump into the
- middle of the designated sequence, in which case there is no
- guarantee that we are in the middle of a sigreturn syscall. Don't
- think this will be a problem in praxis, though. */
-LONGEST
-alpha_linux_sigtramp_offset (CORE_ADDR pc)
+ points to a sequence that copies $sp to $16, loads $0 with the
+ appropriate syscall number, and finally enters the kernel.
+
+ This is somewhat complicated in that:
+ (1) the expansion of the "mov" assembler macro has changed over
+ time, from "bis src,src,dst" to "bis zero,src,dst",
+ (2) the kernel has changed from using "addq" to "lda" to load the
+ syscall number,
+ (3) there is a "normal" sigreturn and an "rt" sigreturn which
+ has a different stack layout.
+*/
+
+static long
+alpha_linux_sigtramp_offset_1 (CORE_ADDR pc)
{
- unsigned int i[3], w;
- long off;
+ switch (alpha_read_insn (pc))
+ {
+ case 0x47de0410: /* bis $30,$30,$16 */
+ case 0x47fe0410: /* bis $31,$30,$16 */
+ return 0;
- if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
- return -1;
+ case 0x43ecf400: /* addq $31,103,$0 */
+ case 0x201f0067: /* lda $0,103($31) */
+ case 0x201f015f: /* lda $0,351($31) */
+ return 4;
+
+ case 0x00000083: /* call_pal callsys */
+ return 8;
- off = -1;
- switch (w)
- {
- case 0x47de0410:
- off = 0;
- break; /* bis $30,$30,$16 */
- case 0x43ecf400:
- off = 4;
- break; /* addq $31,0x67,$0 */
- case 0x00000083:
- off = 8;
- break; /* call_pal callsys */
default:
return -1;
}
+}
+
+static LONGEST
+alpha_linux_sigtramp_offset (CORE_ADDR pc)
+{
+ long i, off;
+
+ if (pc & 3)
+ return -1;
+
+ /* Guess where we might be in the sequence. */
+ off = alpha_linux_sigtramp_offset_1 (pc);
+ if (off < 0)
+ return -1;
+
+ /* Verify that the other two insns of the sequence are as we expect. */
pc -= off;
- if (pc & 0x7)
+ for (i = 0; i < 12; i += 4)
{
- /* designated sequence is not quadword aligned */
- return -1;
+ if (i == off)
+ continue;
+ if (alpha_linux_sigtramp_offset_1 (pc + i) != i)
+ return -1;
}
- if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0)
- return -1;
-
- if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
- return off;
- return -1;
+ return off;
}
static int
alpha_linux_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
{
- return (alpha_linux_sigtramp_offset (pc) >= 0);
+ return alpha_linux_sigtramp_offset (pc) >= 0;
+}
+
+static CORE_ADDR
+alpha_linux_sigcontext_addr (struct frame_info *this_frame)
+{
+ CORE_ADDR pc;
+ ULONGEST sp;
+ long off;
+
+ pc = get_frame_pc (this_frame);
+ sp = get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM);
+
+ off = alpha_linux_sigtramp_offset (pc);
+ gdb_assert (off >= 0);
+
+ /* __NR_rt_sigreturn has a couple of structures on the stack. This is:
+
+ struct rt_sigframe {
+ struct siginfo info;
+ struct ucontext uc;
+ };
+
+ offsetof (struct rt_sigframe, uc.uc_mcontext);
+ */
+ if (alpha_read_insn (pc - off + 4) == 0x201f015f)
+ return sp + 176;
+
+ /* __NR_sigreturn has the sigcontext structure at the top of the stack. */
+ return sp;
+}
+
+/* Supply register REGNUM from the buffer specified by GREGS and LEN
+ in the general-purpose register set REGSET to register cache
+ REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
+
+static void
+alpha_linux_supply_gregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *gregs, size_t len)
+{
+ const gdb_byte *regs = gregs;
+ int i;
+ gdb_assert (len >= 32 * 8);
+
+ for (i = 0; i < ALPHA_ZERO_REGNUM; i++)
+ {
+ if (regnum == i || regnum == -1)
+ regcache_raw_supply (regcache, i, regs + i * 8);
+ }
+
+ if (regnum == ALPHA_PC_REGNUM || regnum == -1)
+ regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
+
+ if (regnum == ALPHA_UNIQUE_REGNUM || regnum == -1)
+ regcache_raw_supply (regcache, ALPHA_UNIQUE_REGNUM,
+ len >= 33 * 8 ? regs + 32 * 8 : NULL);
}
+/* Supply register REGNUM from the buffer specified by FPREGS and LEN
+ in the floating-point register set REGSET to register cache
+ REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
+
static void
-alpha_linux_init_abi (struct gdbarch_info info,
- struct gdbarch *gdbarch)
+alpha_linux_supply_fpregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *fpregs, size_t len)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ const gdb_byte *regs = fpregs;
+ int i;
+ gdb_assert (len >= 32 * 8);
- set_gdbarch_pc_in_sigtramp (gdbarch, alpha_linux_pc_in_sigtramp);
+ for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++)
+ {
+ if (regnum == i || regnum == -1)
+ regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8);
+ }
+
+ if (regnum == ALPHA_FPCR_REGNUM || regnum == -1)
+ regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 31 * 8);
+}
+
+static struct regset alpha_linux_gregset =
+{
+ NULL,
+ alpha_linux_supply_gregset
+};
+
+static struct regset alpha_linux_fpregset =
+{
+ NULL,
+ alpha_linux_supply_fpregset
+};
+/* Return the appropriate register set for the core section identified
+ by SECT_NAME and SECT_SIZE. */
+
+const struct regset *
+alpha_linux_regset_from_core_section (struct gdbarch *gdbarch,
+ const char *sect_name, size_t sect_size)
+{
+ if (strcmp (sect_name, ".reg") == 0 && sect_size >= 32 * 8)
+ return &alpha_linux_gregset;
+
+ if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 32 * 8)
+ return &alpha_linux_fpregset;
+
+ return NULL;
+}
+
+static void
+alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep;
+
+ /* Hook into the DWARF CFI frame unwinder. */
+ alpha_dwarf2_init_abi (info, gdbarch);
+
+ /* Hook into the MDEBUG frame unwinder. */
+ alpha_mdebug_init_abi (info, gdbarch);
+
+ tdep = gdbarch_tdep (gdbarch);
tdep->dynamic_sigtramp_offset = alpha_linux_sigtramp_offset;
+ tdep->sigcontext_addr = alpha_linux_sigcontext_addr;
+ tdep->pc_in_sigtramp = alpha_linux_pc_in_sigtramp;
+ tdep->jb_pc = 2;
+ tdep->jb_elt_size = 8;
+
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, svr4_lp64_fetch_link_map_offsets);
+
+ /* Enable TLS support. */
+ set_gdbarch_fetch_tls_load_module_address (gdbarch,
+ svr4_fetch_objfile_link_map);
+
+ set_gdbarch_regset_from_core_section
+ (gdbarch, alpha_linux_regset_from_core_section);
}
void
_initialize_alpha_linux_tdep (void)
{
- alpha_gdbarch_register_os_abi (ALPHA_ABI_LINUX, alpha_linux_init_abi);
+ gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_LINUX,
+ alpha_linux_init_abi);
}
projects / deliverable / binutils-gdb.git / blobdiff