binutils-gdb/gdb/frv-linux-tdep.c

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/* Target-dependent code for GNU/Linux running on the Fujitsu FR-V,
for GDB.
Copyright (C) 2004-2019 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 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdbcore.h"
#include "target.h"
#include "frame.h"
#include "osabi.h"
#include "regcache.h"
#include "elf-bfd.h"
#include "elf/frv.h"
#include "frv-tdep.h"
#include "trad-frame.h"
#include "frame-unwind.h"
#include "regset.h"
#include "linux-tdep.h"
/* Define the size (in bytes) of an FR-V instruction. */
static const int frv_instr_size = 4;
enum {
NORMAL_SIGTRAMP = 1,
RT_SIGTRAMP = 2
};
static int
frv_linux_pc_in_sigtramp (struct gdbarch *gdbarch, CORE_ADDR pc,
const char *name)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[frv_instr_size];
LONGEST instr;
int retval = 0;
if (target_read_memory (pc, buf, sizeof buf) != 0)
return 0;
instr = extract_unsigned_integer (buf, sizeof buf, byte_order);
if (instr == 0x8efc0077) /* setlos #__NR_sigreturn, gr7 */
retval = NORMAL_SIGTRAMP;
else if (instr == 0x8efc00ad) /* setlos #__NR_rt_sigreturn, gr7 */
retval = RT_SIGTRAMP;
else
return 0;
if (target_read_memory (pc + frv_instr_size, buf, sizeof buf) != 0)
return 0;
instr = extract_unsigned_integer (buf, sizeof buf, byte_order);
if (instr != 0xc0700000) /* tira gr0, 0 */
return 0;
/* If we get this far, we'll return a non-zero value, either
NORMAL_SIGTRAMP (1) or RT_SIGTRAMP (2). */
return retval;
}
/* Given NEXT_FRAME, the "callee" frame of the sigtramp frame that we
wish to decode, and REGNO, one of the frv register numbers defined
in frv-tdep.h, return the address of the saved register (corresponding
to REGNO) in the sigtramp frame. Return -1 if the register is not
found in the sigtramp frame. The magic numbers in the code below
were computed by examining the following kernel structs:
From arch/frv/kernel/signal.c:
struct sigframe
{
void (*pretcode)(void);
int sig;
struct sigcontext sc;
unsigned long extramask[_NSIG_WORDS-1];
uint32_t retcode[2];
};
struct rt_sigframe
{
void (*pretcode)(void);
int sig;
struct siginfo *pinfo;
void *puc;
struct siginfo info;
struct ucontext uc;
uint32_t retcode[2];
};
From include/asm-frv/ucontext.h:
struct ucontext {
unsigned long uc_flags;
struct ucontext *uc_link;
stack_t uc_stack;
struct sigcontext uc_mcontext;
sigset_t uc_sigmask;
};
From include/asm-frv/signal.h:
typedef struct sigaltstack {
void *ss_sp;
int ss_flags;
size_t ss_size;
} stack_t;
From include/asm-frv/sigcontext.h:
struct sigcontext {
struct user_context sc_context;
unsigned long sc_oldmask;
} __attribute__((aligned(8)));
From include/asm-frv/registers.h:
struct user_int_regs
{
unsigned long psr;
unsigned long isr;
unsigned long ccr;
unsigned long cccr;
unsigned long lr;
unsigned long lcr;
unsigned long pc;
unsigned long __status;
unsigned long syscallno;
unsigned long orig_gr8;
unsigned long gner[2];
unsigned long long iacc[1];
union {
unsigned long tbr;
unsigned long gr[64];
};
};
struct user_fpmedia_regs
{
unsigned long fr[64];
unsigned long fner[2];
unsigned long msr[2];
unsigned long acc[8];
unsigned char accg[8];
unsigned long fsr[1];
};
struct user_context
{
struct user_int_regs i;
struct user_fpmedia_regs f;
void *extension;
} __attribute__((aligned(8))); */
static LONGEST
frv_linux_sigcontext_reg_addr (struct frame_info *this_frame, int regno,
CORE_ADDR *sc_addr_cache_ptr)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR sc_addr;
if (sc_addr_cache_ptr && *sc_addr_cache_ptr)
{
sc_addr = *sc_addr_cache_ptr;
}
else
{
CORE_ADDR pc, sp;
gdb_byte buf[4];
int tramp_type;
pc = get_frame_pc (this_frame);
tramp_type = frv_linux_pc_in_sigtramp (gdbarch, pc, 0);
get_frame_register (this_frame, sp_regnum, buf);
sp = extract_unsigned_integer (buf, sizeof buf, byte_order);
if (tramp_type == NORMAL_SIGTRAMP)
{
/* For a normal sigtramp frame, the sigcontext struct starts
at SP + 8. */
sc_addr = sp + 8;
}
else if (tramp_type == RT_SIGTRAMP)
{
/* For a realtime sigtramp frame, SP + 12 contains a pointer
to a ucontext struct. The ucontext struct contains a
sigcontext struct starting 24 bytes in. (The offset of
uc_mcontext within struct ucontext is derived as follows:
stack_t is a 12-byte struct and struct sigcontext is
8-byte aligned. This gives an offset of 8 + 12 + 4 (for
padding) = 24.) */
if (target_read_memory (sp + 12, buf, sizeof buf) != 0)
{
warning (_("Can't read realtime sigtramp frame."));
return 0;
}
sc_addr = extract_unsigned_integer (buf, sizeof buf, byte_order);
sc_addr += 24;
}
else
internal_error (__FILE__, __LINE__, _("not a signal trampoline"));
if (sc_addr_cache_ptr)
*sc_addr_cache_ptr = sc_addr;
}
switch (regno)
{
case psr_regnum :
return sc_addr + 0;
/* sc_addr + 4 has "isr", the Integer Status Register. */
case ccr_regnum :
return sc_addr + 8;
case cccr_regnum :
return sc_addr + 12;
case lr_regnum :
return sc_addr + 16;
case lcr_regnum :
return sc_addr + 20;
case pc_regnum :
return sc_addr + 24;
/* sc_addr + 28 is __status, the exception status.
sc_addr + 32 is syscallno, the syscall number or -1.
sc_addr + 36 is orig_gr8, the original syscall arg #1.
sc_addr + 40 is gner[0].
sc_addr + 44 is gner[1]. */
case iacc0h_regnum :
return sc_addr + 48;
case iacc0l_regnum :
return sc_addr + 52;
default :
if (first_gpr_regnum <= regno && regno <= last_gpr_regnum)
return sc_addr + 56 + 4 * (regno - first_gpr_regnum);
else if (first_fpr_regnum <= regno && regno <= last_fpr_regnum)
return sc_addr + 312 + 4 * (regno - first_fpr_regnum);
else
return -1; /* not saved. */
}
}
/* Signal trampolines. */
static struct trad_frame_cache *
frv_linux_sigtramp_frame_cache (struct frame_info *this_frame,
void **this_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
struct trad_frame_cache *cache;
CORE_ADDR addr;
gdb_byte buf[4];
int regnum;
CORE_ADDR sc_addr_cache_val = 0;
struct frame_id this_id;
if (*this_cache)
return (struct trad_frame_cache *) *this_cache;
cache = trad_frame_cache_zalloc (this_frame);
/* FIXME: cagney/2004-05-01: This is is long standing broken code.
The frame ID's code address should be the start-address of the
signal trampoline and not the current PC within that
trampoline. */
get_frame_register (this_frame, sp_regnum, buf);
addr = extract_unsigned_integer (buf, sizeof buf, byte_order);
this_id = frame_id_build (addr, get_frame_pc (this_frame));
trad_frame_set_id (cache, this_id);
for (regnum = 0; regnum < frv_num_regs; regnum++)
{
LONGEST reg_addr = frv_linux_sigcontext_reg_addr (this_frame, regnum,
&sc_addr_cache_val);
if (reg_addr != -1)
trad_frame_set_reg_addr (cache, regnum, reg_addr);
}
*this_cache = cache;
return cache;
}
static void
frv_linux_sigtramp_frame_this_id (struct frame_info *this_frame,
void **this_cache,
struct frame_id *this_id)
{
struct trad_frame_cache *cache
= frv_linux_sigtramp_frame_cache (this_frame, this_cache);
trad_frame_get_id (cache, this_id);
}
static struct value *
frv_linux_sigtramp_frame_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
{
/* Make sure we've initialized the cache. */
struct trad_frame_cache *cache
= frv_linux_sigtramp_frame_cache (this_frame, this_cache);
return trad_frame_get_register (cache, this_frame, regnum);
}
static int
frv_linux_sigtramp_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
void **this_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
CORE_ADDR pc = get_frame_pc (this_frame);
const char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
if (frv_linux_pc_in_sigtramp (gdbarch, pc, name))
return 1;
return 0;
}
static const struct frame_unwind frv_linux_sigtramp_frame_unwind =
{
SIGTRAMP_FRAME,
default_frame_unwind_stop_reason,
frv_linux_sigtramp_frame_this_id,
frv_linux_sigtramp_frame_prev_register,
NULL,
frv_linux_sigtramp_frame_sniffer
};
/* The FRV kernel defines ELF_NGREG as 46. We add 2 in order to include
the loadmap addresses in the register set. (See below for more info.) */
#define FRV_ELF_NGREG (46 + 2)
typedef unsigned char frv_elf_greg_t[4];
typedef struct { frv_elf_greg_t reg[FRV_ELF_NGREG]; } frv_elf_gregset_t;
typedef unsigned char frv_elf_fpreg_t[4];
typedef struct
{
frv_elf_fpreg_t fr[64];
frv_elf_fpreg_t fner[2];
frv_elf_fpreg_t msr[2];
frv_elf_fpreg_t acc[8];
unsigned char accg[8];
frv_elf_fpreg_t fsr[1];
} frv_elf_fpregset_t;
/* Register maps. */
static const struct regcache_map_entry frv_linux_gregmap[] =
{
{ 1, psr_regnum, 4 },
{ 1, REGCACHE_MAP_SKIP, 4 }, /* isr */
{ 1, ccr_regnum, 4 },
{ 1, cccr_regnum, 4 },
{ 1, lr_regnum, 4 },
{ 1, lcr_regnum, 4 },
{ 1, pc_regnum, 4 },
{ 1, REGCACHE_MAP_SKIP, 4 }, /* __status */
{ 1, REGCACHE_MAP_SKIP, 4 }, /* syscallno */
{ 1, REGCACHE_MAP_SKIP, 4 }, /* orig_gr8 */
{ 1, gner0_regnum, 4 },
{ 1, gner1_regnum, 4 },
{ 1, REGCACHE_MAP_SKIP, 8 }, /* iacc0 */
{ 1, tbr_regnum, 4 },
{ 31, first_gpr_regnum + 1, 4 }, /* gr1 ... gr31 */
/* Technically, the loadmap addresses are not part of `pr_reg' as
found in the elf_prstatus struct. The fields which communicate
the loadmap address appear (by design) immediately after
`pr_reg' though, and the BFD function elf32_frv_grok_prstatus()
has been implemented to include these fields in the register
section that it extracts from the core file. So, for our
purposes, they may be viewed as registers. */
{ 1, fdpic_loadmap_exec_regnum, 4 },
{ 1, fdpic_loadmap_interp_regnum, 4 },
{ 0 }
};
static const struct regcache_map_entry frv_linux_fpregmap[] =
{
{ 64, first_fpr_regnum, 4 }, /* fr0 ... fr63 */
{ 1, fner0_regnum, 4 },
{ 1, fner1_regnum, 4 },
{ 1, msr0_regnum, 4 },
{ 1, msr1_regnum, 4 },
{ 8, acc0_regnum, 4 }, /* acc0 ... acc7 */
{ 1, accg0123_regnum, 4 },
{ 1, accg4567_regnum, 4 },
{ 1, fsr0_regnum, 4 },
{ 0 }
};
/* Unpack an frv_elf_gregset_t into GDB's register cache. */
static void
frv_linux_supply_gregset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *gregs, size_t len)
{
int regi;
/* gr0 always contains 0. Also, the kernel passes the TBR value in
this slot. */
regcache->raw_supply_zeroed (first_gpr_regnum);
/* Fill gr32, ..., gr63 with zeros. */
for (regi = first_gpr_regnum + 32; regi <= last_gpr_regnum; regi++)
regcache->raw_supply_zeroed (regi);
regcache_supply_regset (regset, regcache, regnum, gregs, len);
}
/* FRV Linux kernel register sets. */
static const struct regset frv_linux_gregset =
{
frv_linux_gregmap,
frv_linux_supply_gregset, regcache_collect_regset
};
static const struct regset frv_linux_fpregset =
{
frv_linux_fpregmap,
regcache_supply_regset, regcache_collect_regset
};
static void
frv_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
iterate_over_regset_sections_cb *cb,
void *cb_data,
const struct regcache *regcache)
{
cb (".reg", sizeof (frv_elf_gregset_t), sizeof (frv_elf_gregset_t),
&frv_linux_gregset, NULL, cb_data);
cb (".reg2", sizeof (frv_elf_fpregset_t), sizeof (frv_elf_fpregset_t),
&frv_linux_fpregset, NULL, cb_data);
}
static void
frv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
linux_init_abi (info, gdbarch);
/* Set the sigtramp frame sniffer. */
frame_unwind_append_unwinder (gdbarch, &frv_linux_sigtramp_frame_unwind);
set_gdbarch_iterate_over_regset_sections
(gdbarch, frv_linux_iterate_over_regset_sections);
}
static enum gdb_osabi
frv_linux_elf_osabi_sniffer (bfd *abfd)
{
int elf_flags;
elf_flags = elf_elfheader (abfd)->e_flags;
/* Assume GNU/Linux if using the FDPIC ABI. If/when another OS shows
up that uses this ABI, we'll need to start using .note sections
or some such. */
if (elf_flags & EF_FRV_FDPIC)
return GDB_OSABI_LINUX;
else
return GDB_OSABI_UNKNOWN;
}
void
_initialize_frv_linux_tdep (void)
{
gdbarch_register_osabi (bfd_arch_frv, 0, GDB_OSABI_LINUX,
frv_linux_init_abi);
gdbarch_register_osabi_sniffer (bfd_arch_frv,
bfd_target_elf_flavour,
frv_linux_elf_osabi_sniffer);
}