/* Target-dependent code for GNU/Linux on Alpha.
- Copyright 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002-2020 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 "frame.h"
-#include "gdbcore.h"
-#include "value.h"
#include "osabi.h"
-
+#include "solib-svr4.h"
+#include "symtab.h"
+#include "regset.h"
+#include "regcache.h"
+#include "linux-tdep.h"
#include "alpha-tdep.h"
+#include "gdbarch.h"
+
+/* This enum represents the signals' numbers on the Alpha
+ architecture. It just contains the signal definitions which are
+ different from the generic implementation.
+
+ It is derived from the file <arch/alpha/include/uapi/asm/signal.h>,
+ from the Linux kernel tree. */
+
+enum
+ {
+ /* SIGABRT is the same as in the generic implementation, but is
+ defined here because SIGIOT depends on it. */
+ ALPHA_LINUX_SIGABRT = 6,
+ ALPHA_LINUX_SIGEMT = 7,
+ ALPHA_LINUX_SIGBUS = 10,
+ ALPHA_LINUX_SIGSYS = 12,
+ ALPHA_LINUX_SIGURG = 16,
+ ALPHA_LINUX_SIGSTOP = 17,
+ ALPHA_LINUX_SIGTSTP = 18,
+ ALPHA_LINUX_SIGCONT = 19,
+ ALPHA_LINUX_SIGCHLD = 20,
+ ALPHA_LINUX_SIGIO = 23,
+ ALPHA_LINUX_SIGINFO = 29,
+ ALPHA_LINUX_SIGUSR1 = 30,
+ ALPHA_LINUX_SIGUSR2 = 31,
+ ALPHA_LINUX_SIGPOLL = ALPHA_LINUX_SIGIO,
+ ALPHA_LINUX_SIGPWR = ALPHA_LINUX_SIGINFO,
+ ALPHA_LINUX_SIGIOT = ALPHA_LINUX_SIGABRT,
+ };
-/* 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)
-{
- unsigned int i[3], w;
- long off;
+ points to a sequence that copies $sp to $16, loads $0 with the
+ appropriate syscall number, and finally enters the kernel.
- if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
- return -1;
+ 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. */
- off = -1;
- switch (w)
+static long
+alpha_linux_sigtramp_offset_1 (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ switch (alpha_read_insn (gdbarch, pc))
{
- 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 */
+ case 0x47de0410: /* bis $30,$30,$16 */
+ case 0x47fe0410: /* bis $31,$30,$16 */
+ return 0;
+
+ 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;
+
default:
return -1;
}
+}
+
+static LONGEST
+alpha_linux_sigtramp_offset (struct gdbarch *gdbarch, 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 (gdbarch, 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 (gdbarch, 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)
+alpha_linux_pc_in_sigtramp (struct gdbarch *gdbarch,
+ CORE_ADDR pc, const char *func_name)
{
- return (alpha_linux_sigtramp_offset (pc) >= 0);
+ return alpha_linux_sigtramp_offset (gdbarch, pc) >= 0;
}
static CORE_ADDR
-alpha_linux_sigcontext_addr (struct frame_info *frame)
+alpha_linux_sigcontext_addr (struct frame_info *this_frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (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 (gdbarch, 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 (gdbarch, 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 = (const gdb_byte *) gregs;
+
+ gdb_assert (len >= 32 * 8);
+ alpha_supply_int_regs (regcache, regnum, regs, regs + 31 * 8,
+ len >= 33 * 8 ? regs + 32 * 8 : NULL);
+}
+
+/* Collect register REGNUM from the register cache REGCACHE and store
+ it in the buffer specified by GREGS and LEN as described by the
+ general-purpose register set REGSET. If REGNUM is -1, do this for
+ all registers in REGSET. */
+
+static void
+alpha_linux_collect_gregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *gregs, size_t len)
+{
+ gdb_byte *regs = (gdb_byte *) gregs;
+
+ gdb_assert (len >= 32 * 8);
+ alpha_fill_int_regs (regcache, regnum, regs, regs + 31 * 8,
+ 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_supply_fpregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *fpregs, size_t len)
+{
+ const gdb_byte *regs = (const gdb_byte *) fpregs;
+
+ gdb_assert (len >= 32 * 8);
+ alpha_supply_fp_regs (regcache, regnum, regs, regs + 31 * 8);
+}
+
+/* Collect register REGNUM from the register cache REGCACHE and store
+ it in the buffer specified by FPREGS and LEN as described by the
+ general-purpose register set REGSET. If REGNUM is -1, do this for
+ all registers in REGSET. */
+
+static void
+alpha_linux_collect_fpregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *fpregs, size_t len)
+{
+ gdb_byte *regs = (gdb_byte *) fpregs;
+
+ gdb_assert (len >= 32 * 8);
+ alpha_fill_fp_regs (regcache, regnum, regs, regs + 31 * 8);
+}
+
+static const struct regset alpha_linux_gregset =
+{
+ NULL,
+ alpha_linux_supply_gregset, alpha_linux_collect_gregset
+};
+
+static const struct regset alpha_linux_fpregset =
+{
+ NULL,
+ alpha_linux_supply_fpregset, alpha_linux_collect_fpregset
+};
+
+/* Iterate over core file register note sections. */
+
+static void
+alpha_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
+ iterate_over_regset_sections_cb *cb,
+ void *cb_data,
+ const struct regcache *regcache)
{
- return (get_frame_base (frame) - 0x298); /* sizeof(struct sigcontext) */
+ cb (".reg", 32 * 8, 32 * 8, &alpha_linux_gregset, NULL, cb_data);
+ cb (".reg2", 32 * 8, 32 * 8, &alpha_linux_fpregset, NULL, cb_data);
+}
+
+/* Implementation of `gdbarch_gdb_signal_from_target', as defined in
+ gdbarch.h. */
+
+static enum gdb_signal
+alpha_linux_gdb_signal_from_target (struct gdbarch *gdbarch,
+ int signal)
+{
+ switch (signal)
+ {
+ case ALPHA_LINUX_SIGEMT:
+ return GDB_SIGNAL_EMT;
+
+ case ALPHA_LINUX_SIGBUS:
+ return GDB_SIGNAL_BUS;
+
+ case ALPHA_LINUX_SIGSYS:
+ return GDB_SIGNAL_SYS;
+
+ case ALPHA_LINUX_SIGURG:
+ return GDB_SIGNAL_URG;
+
+ case ALPHA_LINUX_SIGSTOP:
+ return GDB_SIGNAL_STOP;
+
+ case ALPHA_LINUX_SIGTSTP:
+ return GDB_SIGNAL_TSTP;
+
+ case ALPHA_LINUX_SIGCONT:
+ return GDB_SIGNAL_CONT;
+
+ case ALPHA_LINUX_SIGCHLD:
+ return GDB_SIGNAL_CHLD;
+
+ /* No way to differentiate between SIGIO and SIGPOLL.
+ Therefore, we just handle the first one. */
+ case ALPHA_LINUX_SIGIO:
+ return GDB_SIGNAL_IO;
+
+ /* No way to differentiate between SIGINFO and SIGPWR.
+ Therefore, we just handle the first one. */
+ case ALPHA_LINUX_SIGINFO:
+ return GDB_SIGNAL_INFO;
+
+ case ALPHA_LINUX_SIGUSR1:
+ return GDB_SIGNAL_USR1;
+
+ case ALPHA_LINUX_SIGUSR2:
+ return GDB_SIGNAL_USR2;
+ }
+
+ return linux_gdb_signal_from_target (gdbarch, signal);
+}
+
+/* Implementation of `gdbarch_gdb_signal_to_target', as defined in
+ gdbarch.h. */
+
+static int
+alpha_linux_gdb_signal_to_target (struct gdbarch *gdbarch,
+ enum gdb_signal signal)
+{
+ switch (signal)
+ {
+ case GDB_SIGNAL_EMT:
+ return ALPHA_LINUX_SIGEMT;
+
+ case GDB_SIGNAL_BUS:
+ return ALPHA_LINUX_SIGBUS;
+
+ case GDB_SIGNAL_SYS:
+ return ALPHA_LINUX_SIGSYS;
+
+ case GDB_SIGNAL_URG:
+ return ALPHA_LINUX_SIGURG;
+
+ case GDB_SIGNAL_STOP:
+ return ALPHA_LINUX_SIGSTOP;
+
+ case GDB_SIGNAL_TSTP:
+ return ALPHA_LINUX_SIGTSTP;
+
+ case GDB_SIGNAL_CONT:
+ return ALPHA_LINUX_SIGCONT;
+
+ case GDB_SIGNAL_CHLD:
+ return ALPHA_LINUX_SIGCHLD;
+
+ case GDB_SIGNAL_IO:
+ return ALPHA_LINUX_SIGIO;
+
+ case GDB_SIGNAL_INFO:
+ return ALPHA_LINUX_SIGINFO;
+
+ case GDB_SIGNAL_USR1:
+ return ALPHA_LINUX_SIGUSR1;
+
+ case GDB_SIGNAL_USR2:
+ return ALPHA_LINUX_SIGUSR2;
+
+ case GDB_SIGNAL_POLL:
+ return ALPHA_LINUX_SIGPOLL;
+
+ case GDB_SIGNAL_PWR:
+ return ALPHA_LINUX_SIGPWR;
+ }
+
+ return linux_gdb_signal_to_target (gdbarch, signal);
}
static void
-alpha_linux_init_abi (struct gdbarch_info info,
- struct gdbarch *gdbarch)
+alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ struct gdbarch_tdep *tdep;
+
+ linux_init_abi (info, gdbarch);
+
+ /* Hook into the DWARF CFI frame unwinder. */
+ alpha_dwarf2_init_abi (info, gdbarch);
- set_gdbarch_pc_in_sigtramp (gdbarch, alpha_linux_pc_in_sigtramp);
+ /* 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_iterate_over_regset_sections
+ (gdbarch, alpha_linux_iterate_over_regset_sections);
+
+ set_gdbarch_gdb_signal_from_target (gdbarch,
+ alpha_linux_gdb_signal_from_target);
+ set_gdbarch_gdb_signal_to_target (gdbarch,
+ alpha_linux_gdb_signal_to_target);
}
+void _initialize_alpha_linux_tdep ();
void
-_initialize_alpha_linux_tdep (void)
+_initialize_alpha_linux_tdep ()
{
gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_LINUX,
alpha_linux_init_abi);
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