/* Target-dependent code for GNU/Linux SPARC.
- Copyright 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 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 "floatformat.h"
+#include "dwarf2-frame.h"
#include "frame.h"
#include "frame-unwind.h"
-#include "tramp-frame.h"
+#include "gdbtypes.h"
+#include "regset.h"
#include "gdbarch.h"
#include "gdbcore.h"
#include "osabi.h"
#include "solib-svr4.h"
#include "symtab.h"
#include "trad-frame.h"
+#include "tramp-frame.h"
#include "sparc-tdep.h"
/* Signal trampoline support. */
+static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
+ struct frame_info *this_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func);
+
/* GNU/Linux has two flavors of signals. Normal signal handlers, and
"realtime" (RT) signals. The RT signals can provide additional
information to the signal handler if the SA_SIGINFO flag is set
/* When the sparc Linux kernel calls a signal handler and the
SA_RESTORER flag isn't set, the return address points to a bit of
- code on the stack. This function returns whether the PC appears to
- be within this bit of code.
-
- The instruction sequence for normal signals is
- mov __NR_sigreturn, %g1 ! hex: 0x821020d8
- ta 0x10 ! hex: 0x91d02010
+ code on the stack. This code checks whether the PC appears to be
+ within this bit of code.
+ The instruction sequence for normal signals is encoded below.
Checking for the code sequence should be somewhat reliable, because
the effect is to call the system call sigreturn. This is unlikely
- to occur anywhere other than a signal trampoline.
-
- It kind of sucks that we have to read memory from the process in
- order to identify a signal trampoline, but there doesn't seem to be
- any other way. However, sparc32_linux_pc_in_sigtramp arranges to
- only call us if no function name could be identified, which should
- be the case since the code is on the stack. */
-
-#define LINUX32_SIGTRAMP_INSN0 0x821020d8 /* mov __NR_sigreturn, %g1 */
-#define LINUX32_SIGTRAMP_INSN1 0x91d02010 /* ta 0x10 */
+ to occur anywhere other than a signal trampoline. */
-/* The instruction sequence for RT signals is
- mov __NR_rt_sigreturn, %g1 ! hex: 0x82102065
- ta {0x10,0x6d} ! hex: 0x91d02010
-
- The effect is to call the system call rt_sigreturn.
- Note that 64-bit binaries only use this RT signal return method. */
-
-#define LINUX32_RT_SIGTRAMP_INSN0 0x82102065
-#define LINUX32_RT_SIGTRAMP_INSN1 0x91d02010
-
-static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
- struct frame_info *next_frame,
- struct trad_frame_cache *this_cache,
- CORE_ADDR func);
-
-static const struct tramp_frame sparc32_linux_sigframe = {
+static const struct tramp_frame sparc32_linux_sigframe =
+{
SIGTRAMP_FRAME,
4,
{
- { LINUX32_SIGTRAMP_INSN0, -1 },
- { LINUX32_SIGTRAMP_INSN1, -1 },
+ { 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
+ { 0x91d02010, -1 }, /* ta 0x10 */
{ TRAMP_SENTINEL_INSN, -1 }
},
sparc32_linux_sigframe_init
};
-static const struct tramp_frame sparc32_linux_rt_sigframe = {
+/* The instruction sequence for RT signals is slightly different. The
+ effect is to call the system call rt_sigreturn. */
+
+static const struct tramp_frame sparc32_linux_rt_sigframe =
+{
SIGTRAMP_FRAME,
4,
{
- { LINUX32_RT_SIGTRAMP_INSN0, -1 },
- { LINUX32_RT_SIGTRAMP_INSN1, -1 },
+ { 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
+ { 0x91d02010, -1 }, /* ta 0x10 */
{ TRAMP_SENTINEL_INSN, -1 }
},
sparc32_linux_sigframe_init
static void
sparc32_linux_sigframe_init (const struct tramp_frame *self,
- struct frame_info *next_frame,
+ struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
- CORE_ADDR base, addr;
+ CORE_ADDR base, addr, sp_addr;
int regnum;
- base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
+ base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
if (self == &sparc32_linux_rt_sigframe)
base += 128;
- /* Offsets from <bits/sigcontext.h> */
+ /* Offsets from <bits/sigcontext.h>. */
- trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0x00);
- trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 0x04);
- trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 0x08);
- trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 0x0c);
+ trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
+ trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
+ trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
+ trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);
/* Since %g0 is always zero, keep the identity encoding. */
- addr = base + 0x14;
+ addr = base + 20;
+ sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
{
trad_frame_set_reg_addr (this_cache, regnum, addr);
addr += 4;
}
- base = addr = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
+ base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
+ addr = get_frame_memory_unsigned (this_frame, sp_addr, 4);
+
for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
{
trad_frame_set_reg_addr (this_cache, regnum, addr);
}
trad_frame_set_id (this_cache, frame_id_build (base, func));
}
+\f
+/* Return the address of a system call's alternative return
+ address. */
+
+static CORE_ADDR
+sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
+{
+ if (insn == 0x91d02010)
+ {
+ ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
+
+ /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
+ if (sc_num == 101 || sc_num == 216)
+ {
+ ULONGEST sp, pc_offset;
+
+ sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
+
+ /* The kernel puts the sigreturn registers on the stack,
+ and this is where the signal unwinding state is take from
+ when returning from a signal.
+
+ For __NR_sigreturn, this register area sits 96 bytes from
+ the base of the stack. The saved PC sits 4 bytes into the
+ sigreturn register save area.
+
+ For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
+ right before the sigreturn register save area. */
+
+ pc_offset = 96 + 4;
+ if (sc_num == 101)
+ pc_offset += 128;
+
+ return read_memory_unsigned_integer (sp + pc_offset, 4);
+ }
+ }
+
+ return 0;
+}
+\f
+
+const struct sparc_gregset sparc32_linux_core_gregset =
+{
+ 32 * 4, /* %psr */
+ 33 * 4, /* %pc */
+ 34 * 4, /* %npc */
+ 35 * 4, /* %y */
+ -1, /* %wim */
+ -1, /* %tbr */
+ 1 * 4, /* %g1 */
+ 16 * 4, /* %l0 */
+ 4, /* y size */
+};
+\f
+
+static void
+sparc32_linux_supply_core_gregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *gregs, size_t len)
+{
+ sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
+}
+
+static void
+sparc32_linux_collect_core_gregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *gregs, size_t len)
+{
+ sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
+}
+
+static void
+sparc32_linux_supply_core_fpregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *fpregs, size_t len)
+{
+ sparc32_supply_fpregset (regcache, regnum, fpregs);
+}
+
+static void
+sparc32_linux_collect_core_fpregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *fpregs, size_t len)
+{
+ sparc32_collect_fpregset (regcache, regnum, fpregs);
+}
+
+/* Set the program counter for process PTID to PC. */
+
+#define PSR_SYSCALL 0x00004000
+
+static void
+sparc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
+ ULONGEST psr;
+
+ regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
+ regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
+
+ /* Clear the "in syscall" bit to prevent the kernel from
+ messing with the PCs we just installed, if we happen to be
+ within an interrupted system call that the kernel wants to
+ restart.
+
+ Note that after we return from the dummy call, the PSR et al.
+ registers will be automatically restored, and the kernel
+ continues to restart the system call at this point. */
+ regcache_cooked_read_unsigned (regcache, SPARC32_PSR_REGNUM, &psr);
+ psr &= ~PSR_SYSCALL;
+ regcache_cooked_write_unsigned (regcache, SPARC32_PSR_REGNUM, psr);
+}
\f
static void
sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
+ sparc32_linux_collect_core_gregset);
+ tdep->sizeof_gregset = 152;
+
+ tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
+ sparc32_linux_collect_core_fpregset);
+ tdep->sizeof_fpregset = 396;
+
tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);
- /* GNU/Linux is very similar to Solaris ... */
- sparc32_sol2_init_abi (info, gdbarch);
+ /* GNU/Linux has SVR4-style shared libraries... */
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, svr4_ilp32_fetch_link_map_offsets);
- /* ... but doesn't have kernel-assisted single-stepping support. */
- set_gdbarch_software_single_step (gdbarch, sparc_software_single_step);
-
- /* GNU/Linux doesn't support the 128-bit `long double' from the psABI. */
- set_gdbarch_long_double_bit (gdbarch, 64);
- set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
+ /* ...which means that we need some special handling when doing
+ prologue analysis. */
+ tdep->plt_entry_size = 12;
/* Enable TLS support. */
set_gdbarch_fetch_tls_load_module_address (gdbarch,
svr4_fetch_objfile_link_map);
+
+ /* Make sure we can single-step over signal return system calls. */
+ tdep->step_trap = sparc32_linux_step_trap;
+
+ /* Hook in the DWARF CFI frame unwinder. */
+ dwarf2_append_unwinders (gdbarch);
+
+ set_gdbarch_write_pc (gdbarch, sparc_linux_write_pc);
}
/* Provide a prototype to silence -Wmissing-prototypes. */