/* GNU/Linux on ARM target support.
- Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+ Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+ Free Software Foundation, Inc.
This file is part of GDB.
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. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
#include "defs.h"
#include "target.h"
#include "frame.h"
#include "regcache.h"
#include "doublest.h"
+#include "solib-svr4.h"
+#include "osabi.h"
+#include "trad-frame.h"
+#include "tramp-frame.h"
#include "arm-tdep.h"
+#include "glibc-tdep.h"
-/* For arm_linux_skip_solib_resolver. */
-#include "symtab.h"
-#include "symfile.h"
-#include "objfiles.h"
+#include "gdb_string.h"
/* Under ARM GNU/Linux the traditional way of performing a breakpoint
is to execute a particular software interrupt, rather than use a
particular undefined instruction to provoke a trap. Upon exection
of the software interrupt the kernel stops the inferior with a
- SIGTRAP, and wakes the debugger. Since ARM GNU/Linux is little
- endian, and doesn't support Thumb at the moment we only override
- the ARM little-endian breakpoint. */
+ SIGTRAP, and wakes the debugger. */
-static const char arm_linux_arm_le_breakpoint[] = {0x01,0x00,0x9f,0xef};
+static const char arm_linux_arm_le_breakpoint[] = { 0x01, 0x00, 0x9f, 0xef };
-/* CALL_DUMMY_WORDS:
- This sequence of words is the instructions
+static const char arm_linux_arm_be_breakpoint[] = { 0xef, 0x9f, 0x00, 0x01 };
- mov lr, pc
- mov pc, r4
- swi bkpt_swi
+/* However, the EABI syscall interface (new in Nov. 2005) does not look at
+ the operand of the swi if old-ABI compatibility is disabled. Therefore,
+ use an undefined instruction instead. This is supported as of kernel
+ version 2.5.70 (May 2003), so should be a safe assumption for EABI
+ binaries. */
- Note this is 12 bytes. */
+static const char eabi_linux_arm_le_breakpoint[] = { 0xf0, 0x01, 0xf0, 0xe7 };
-LONGEST arm_linux_call_dummy_words[] =
-{
- 0xe1a0e00f, 0xe1a0f004, 0xef9f001
-};
+static const char eabi_linux_arm_be_breakpoint[] = { 0xe7, 0xf0, 0x01, 0xf0 };
+
+/* All the kernels which support Thumb support using a specific undefined
+ instruction for the Thumb breakpoint. */
+
+static const char arm_linux_thumb_be_breakpoint[] = {0xde, 0x01};
+
+static const char arm_linux_thumb_le_breakpoint[] = {0x01, 0xde};
/* Description of the longjmp buffer. */
-#define JB_ELEMENT_SIZE INT_REGISTER_RAW_SIZE
-#define JB_PC 21
+#define ARM_LINUX_JB_ELEMENT_SIZE INT_REGISTER_SIZE
+#define ARM_LINUX_JB_PC 21
/* Extract from an array REGBUF containing the (raw) register state
a function return value of type TYPE, and copy that, in virtual format,
into VALBUF. */
-
-void
+/* FIXME rearnsha/2002-02-23: This function shouldn't be necessary.
+ The ARM generic one should be able to handle the model used by
+ linux and the low-level formatting of the registers should be
+ hidden behind the regcache abstraction. */
+static void
arm_linux_extract_return_value (struct type *type,
- char regbuf[REGISTER_BYTES],
+ char regbuf[],
char *valbuf)
{
/* ScottB: This needs to be looked at to handle the different
int regnum = ((TYPE_CODE_FLT == TYPE_CODE (type))
? ARM_F0_REGNUM : ARM_A1_REGNUM);
- memcpy (valbuf, ®buf[REGISTER_BYTE (regnum)], TYPE_LENGTH (type));
+ memcpy (valbuf, ®buf[DEPRECATED_REGISTER_BYTE (regnum)], TYPE_LENGTH (type));
}
-
-/* Note: ScottB
-
- This function does not support passing parameters using the FPA
- variant of the APCS. It passes any floating point arguments in the
- general registers and/or on the stack.
-
- FIXME: This and arm_push_arguments should be merged. However this
- function breaks on a little endian host, big endian target
- using the COFF file format. ELF is ok.
-
- ScottB. */
-
-/* Addresses for calling Thumb functions have the bit 0 set.
- Here are some macros to test, set, or clear bit 0 of addresses. */
-#define IS_THUMB_ADDR(addr) ((addr) & 1)
-#define MAKE_THUMB_ADDR(addr) ((addr) | 1)
-#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
-CORE_ADDR
-arm_linux_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
- int struct_return, CORE_ADDR struct_addr)
-{
- char *fp;
- int argnum, argreg, nstack_size;
-
- /* Walk through the list of args and determine how large a temporary
- stack is required. Need to take care here as structs may be
- passed on the stack, and we have to to push them. */
- nstack_size = -4 * REGISTER_SIZE; /* Some arguments go into A1-A4. */
-
- if (struct_return) /* The struct address goes in A1. */
- nstack_size += REGISTER_SIZE;
-
- /* Walk through the arguments and add their size to nstack_size. */
- for (argnum = 0; argnum < nargs; argnum++)
- {
- int len;
- struct type *arg_type;
-
- arg_type = check_typedef (VALUE_TYPE (args[argnum]));
- len = TYPE_LENGTH (arg_type);
-
- /* ANSI C code passes float arguments as integers, K&R code
- passes float arguments as doubles. Correct for this here. */
- if (TYPE_CODE_FLT == TYPE_CODE (arg_type) && REGISTER_SIZE == len)
- nstack_size += FP_REGISTER_VIRTUAL_SIZE;
- else
- nstack_size += len;
- }
-
- /* Allocate room on the stack, and initialize our stack frame
- pointer. */
- fp = NULL;
- if (nstack_size > 0)
- {
- sp -= nstack_size;
- fp = (char *) sp;
- }
-
- /* Initialize the integer argument register pointer. */
- argreg = ARM_A1_REGNUM;
-
- /* The struct_return pointer occupies the first parameter passing
- register. */
- if (struct_return)
- write_register (argreg++, struct_addr);
-
- /* Process arguments from left to right. Store as many as allowed
- in the parameter passing registers (A1-A4), and save the rest on
- the temporary stack. */
- for (argnum = 0; argnum < nargs; argnum++)
- {
- int len;
- char *val;
- CORE_ADDR regval;
- enum type_code typecode;
- struct type *arg_type, *target_type;
-
- arg_type = check_typedef (VALUE_TYPE (args[argnum]));
- target_type = TYPE_TARGET_TYPE (arg_type);
- len = TYPE_LENGTH (arg_type);
- typecode = TYPE_CODE (arg_type);
- val = (char *) VALUE_CONTENTS (args[argnum]);
-
- /* ANSI C code passes float arguments as integers, K&R code
- passes float arguments as doubles. The .stabs record for
- for ANSI prototype floating point arguments records the
- type as FP_INTEGER, while a K&R style (no prototype)
- .stabs records the type as FP_FLOAT. In this latter case
- the compiler converts the float arguments to double before
- calling the function. */
- if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
- {
- DOUBLEST dblval;
- dblval = extract_floating (val, len);
- len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
- val = alloca (len);
- store_floating (val, len, dblval);
- }
-
- /* If the argument is a pointer to a function, and it is a Thumb
- function, set the low bit of the pointer. */
- if (TYPE_CODE_PTR == typecode
- && NULL != target_type
- && TYPE_CODE_FUNC == TYPE_CODE (target_type))
- {
- CORE_ADDR regval = extract_address (val, len);
- if (arm_pc_is_thumb (regval))
- store_address (val, len, MAKE_THUMB_ADDR (regval));
- }
-
- /* Copy the argument to general registers or the stack in
- register-sized pieces. Large arguments are split between
- registers and stack. */
- while (len > 0)
- {
- int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
-
- if (argreg <= ARM_LAST_ARG_REGNUM)
- {
- /* It's an argument being passed in a general register. */
- regval = extract_address (val, partial_len);
- write_register (argreg++, regval);
- }
- else
- {
- /* Push the arguments onto the stack. */
- write_memory ((CORE_ADDR) fp, val, REGISTER_SIZE);
- fp += REGISTER_SIZE;
- }
-
- len -= partial_len;
- val += partial_len;
- }
- }
-
- /* Return adjusted stack pointer. */
- return sp;
-}
-
/*
Dynamic Linking on ARM GNU/Linux
--------------------------------
with. Before the fixup/resolver code returns, it actually calls
the requested function and repairs &GOT[n+3]. */
-/* Find the minimal symbol named NAME, and return both the minsym
- struct and its objfile. This probably ought to be in minsym.c, but
- everything there is trying to deal with things like C++ and
- SOFUN_ADDRESS_MAYBE_TURQUOISE, ... Since this is so simple, it may
- be considered too special-purpose for general consumption. */
-
-static struct minimal_symbol *
-find_minsym_and_objfile (char *name, struct objfile **objfile_p)
-{
- struct objfile *objfile;
-
- ALL_OBJFILES (objfile)
- {
- struct minimal_symbol *msym;
-
- ALL_OBJFILE_MSYMBOLS (objfile, msym)
- {
- if (SYMBOL_NAME (msym)
- && STREQ (SYMBOL_NAME (msym), name))
- {
- *objfile_p = objfile;
- return msym;
- }
- }
- }
-
- return 0;
-}
-
-
-static CORE_ADDR
-skip_hurd_resolver (CORE_ADDR pc)
-{
- /* The HURD dynamic linker is part of the GNU C library, so many
- GNU/Linux distributions use it. (All ELF versions, as far as I
- know.) An unresolved PLT entry points to "_dl_runtime_resolve",
- which calls "fixup" to patch the PLT, and then passes control to
- the function.
-
- We look for the symbol `_dl_runtime_resolve', and find `fixup' in
- the same objfile. If we are at the entry point of `fixup', then
- we set a breakpoint at the return address (at the top of the
- stack), and continue.
-
- It's kind of gross to do all these checks every time we're
- called, since they don't change once the executable has gotten
- started. But this is only a temporary hack --- upcoming versions
- of GNU/Linux will provide a portable, efficient interface for
- debugging programs that use shared libraries. */
-
- struct objfile *objfile;
- struct minimal_symbol *resolver
- = find_minsym_and_objfile ("_dl_runtime_resolve", &objfile);
-
- if (resolver)
- {
- struct minimal_symbol *fixup
- = lookup_minimal_symbol ("fixup", NULL, objfile);
-
- if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc)
- return (SAVED_PC_AFTER_CALL (get_current_frame ()));
- }
-
- return 0;
-}
-
-/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c.
- This function:
- 1) decides whether a PLT has sent us into the linker to resolve
- a function reference, and
- 2) if so, tells us where to set a temporary breakpoint that will
- trigger when the dynamic linker is done. */
-
-CORE_ADDR
-arm_linux_skip_solib_resolver (CORE_ADDR pc)
-{
- CORE_ADDR result;
-
- /* Plug in functions for other kinds of resolvers here. */
- result = skip_hurd_resolver (pc);
-
- if (result)
- return result;
-
- return 0;
-}
-
/* The constants below were determined by examining the following files
in the linux kernel sources:
#define ARM_LINUX_SIGRETURN_INSTR 0xef900077
#define ARM_LINUX_RT_SIGRETURN_INSTR 0xef9000ad
-/* arm_linux_in_sigtramp determines if PC points at one of the
- instructions which cause control to return to the Linux kernel upon
- return from a signal handler. FUNC_NAME is unused. */
+/* For ARM EABI, recognize the pattern that glibc uses... alternatively,
+ we could arrange to do this by function name, but they are not always
+ exported. */
+#define ARM_SET_R7_SIGRETURN 0xe3a07077
+#define ARM_SET_R7_RT_SIGRETURN 0xe3a070ad
+#define ARM_EABI_SYSCALL 0xef000000
-int
-arm_linux_in_sigtramp (CORE_ADDR pc, char *func_name)
+static void
+arm_linux_sigtramp_cache (struct frame_info *next_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func, int regs_offset)
{
- unsigned long inst;
+ CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM);
+ CORE_ADDR base = sp + regs_offset;
+ int i;
- inst = read_memory_integer (pc, 4);
+ for (i = 0; i < 16; i++)
+ trad_frame_set_reg_addr (this_cache, i, base + i * 4);
- return (inst == ARM_LINUX_SIGRETURN_INSTR
- || inst == ARM_LINUX_RT_SIGRETURN_INSTR);
+ trad_frame_set_reg_addr (this_cache, ARM_PS_REGNUM, base + 16 * 4);
+ /* The VFP or iWMMXt registers may be saved on the stack, but there's
+ no reliable way to restore them (yet). */
+
+ /* Save a frame ID. */
+ trad_frame_set_id (this_cache, frame_id_build (sp, func));
}
-/* arm_linux_sigcontext_register_address returns the address in the
- sigcontext of register REGNO given a stack pointer value SP and
- program counter value PC. The value 0 is returned if PC is not
- pointing at one of the signal return instructions or if REGNO is
- not saved in the sigcontext struct. */
+static void
+arm_linux_sigreturn_init (const struct tramp_frame *self,
+ struct frame_info *next_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func)
+{
+ arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ 0x0c /* Offset to registers. */);
+}
-CORE_ADDR
-arm_linux_sigcontext_register_address (CORE_ADDR sp, CORE_ADDR pc, int regno)
+static void
+arm_linux_rt_sigreturn_init (const struct tramp_frame *self,
+ struct frame_info *next_frame,
+ struct trad_frame_cache *this_cache,
+ CORE_ADDR func)
{
- unsigned long inst;
- CORE_ADDR reg_addr = 0;
+ arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ 0x88 /* Offset to ucontext_t. */
+ + 0x14 /* Offset to sigcontext. */
+ + 0x0c /* Offset to registers. */);
+}
- inst = read_memory_integer (pc, 4);
+static struct tramp_frame arm_linux_sigreturn_tramp_frame = {
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { ARM_LINUX_SIGRETURN_INSTR, -1 },
+ { TRAMP_SENTINEL_INSN }
+ },
+ arm_linux_sigreturn_init
+};
- if (inst == ARM_LINUX_SIGRETURN_INSTR
- || inst == ARM_LINUX_RT_SIGRETURN_INSTR)
- {
- CORE_ADDR sigcontext_addr;
-
- /* The sigcontext structure is at different places for the two
- signal return instructions. For ARM_LINUX_SIGRETURN_INSTR,
- it starts at the SP value. For ARM_LINUX_RT_SIGRETURN_INSTR,
- it is at SP+8. For the latter instruction, it may also be
- the case that the address of this structure may be determined
- by reading the 4 bytes at SP, but I'm not convinced this is
- reliable.
-
- In any event, these magic constants (0 and 8) may be
- determined by examining struct sigframe and struct
- rt_sigframe in arch/arm/kernel/signal.c in the Linux kernel
- sources. */
-
- if (inst == ARM_LINUX_RT_SIGRETURN_INSTR)
- sigcontext_addr = sp + 8;
- else /* inst == ARM_LINUX_SIGRETURN_INSTR */
- sigcontext_addr = sp + 0;
-
- /* The layout of the sigcontext structure for ARM GNU/Linux is
- in include/asm-arm/sigcontext.h in the Linux kernel sources.
-
- There are three 4-byte fields which precede the saved r0
- field. (This accounts for the 12 in the code below.) The
- sixteen registers (4 bytes per field) follow in order. The
- PSR value follows the sixteen registers which accounts for
- the constant 19 below. */
-
- if (0 <= regno && regno <= ARM_PC_REGNUM)
- reg_addr = sigcontext_addr + 12 + (4 * regno);
- else if (regno == ARM_PS_REGNUM)
- reg_addr = sigcontext_addr + 19 * 4;
- }
+static struct tramp_frame arm_linux_rt_sigreturn_tramp_frame = {
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { ARM_LINUX_RT_SIGRETURN_INSTR, -1 },
+ { TRAMP_SENTINEL_INSN }
+ },
+ arm_linux_rt_sigreturn_init
+};
- return reg_addr;
-}
+static struct tramp_frame arm_eabi_linux_sigreturn_tramp_frame = {
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { ARM_SET_R7_SIGRETURN, -1 },
+ { ARM_EABI_SYSCALL, -1 },
+ { TRAMP_SENTINEL_INSN }
+ },
+ arm_linux_sigreturn_init
+};
+
+static struct tramp_frame arm_eabi_linux_rt_sigreturn_tramp_frame = {
+ SIGTRAMP_FRAME,
+ 4,
+ {
+ { ARM_SET_R7_RT_SIGRETURN, -1 },
+ { ARM_EABI_SYSCALL, -1 },
+ { TRAMP_SENTINEL_INSN }
+ },
+ arm_linux_rt_sigreturn_init
+};
static void
arm_linux_init_abi (struct gdbarch_info info,
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
tdep->lowest_pc = 0x8000;
- tdep->arm_breakpoint = arm_linux_arm_le_breakpoint;
+ if (info.byte_order == BFD_ENDIAN_BIG)
+ {
+ if (tdep->arm_abi == ARM_ABI_AAPCS)
+ tdep->arm_breakpoint = eabi_linux_arm_be_breakpoint;
+ else
+ tdep->arm_breakpoint = arm_linux_arm_be_breakpoint;
+ tdep->thumb_breakpoint = arm_linux_thumb_be_breakpoint;
+ }
+ else
+ {
+ if (tdep->arm_abi == ARM_ABI_AAPCS)
+ tdep->arm_breakpoint = eabi_linux_arm_le_breakpoint;
+ else
+ tdep->arm_breakpoint = arm_linux_arm_le_breakpoint;
+ tdep->thumb_breakpoint = arm_linux_thumb_le_breakpoint;
+ }
tdep->arm_breakpoint_size = sizeof (arm_linux_arm_le_breakpoint);
+ tdep->thumb_breakpoint_size = sizeof (arm_linux_thumb_le_breakpoint);
+
+ if (tdep->fp_model == ARM_FLOAT_AUTO)
+ tdep->fp_model = ARM_FLOAT_FPA;
+
+ tdep->jb_pc = ARM_LINUX_JB_PC;
+ tdep->jb_elt_size = ARM_LINUX_JB_ELEMENT_SIZE;
+
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+
+ /* The following override shouldn't be needed. */
+ set_gdbarch_deprecated_extract_return_value (gdbarch, arm_linux_extract_return_value);
+
+ /* Shared library handling. */
+ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+ set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
+
+ /* Enable TLS support. */
+ set_gdbarch_fetch_tls_load_module_address (gdbarch,
+ svr4_fetch_objfile_link_map);
- tdep->jb_pc = JB_PC;
- tdep->jb_elt_size = JB_ELEMENT_SIZE;
+ tramp_frame_prepend_unwinder (gdbarch,
+ &arm_linux_sigreturn_tramp_frame);
+ tramp_frame_prepend_unwinder (gdbarch,
+ &arm_linux_rt_sigreturn_tramp_frame);
+ tramp_frame_prepend_unwinder (gdbarch,
+ &arm_eabi_linux_sigreturn_tramp_frame);
+ tramp_frame_prepend_unwinder (gdbarch,
+ &arm_eabi_linux_rt_sigreturn_tramp_frame);
}
void
_initialize_arm_linux_tdep (void)
{
- arm_gdbarch_register_os_abi (ARM_ABI_LINUX, arm_linux_init_abi);
+ gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_LINUX,
+ arm_linux_init_abi);
}
projects / deliverable / binutils-gdb.git / blobdiff