/* Native-dependent code for GNU/Linux x86-64.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ Copyright (C) 2001-2020 Free Software Foundation, Inc.
Contributed by Jiri Smid, SuSE Labs.
This file is part of GDB.
#include "defs.h"
#include "inferior.h"
-#include "gdbcore.h"
#include "regcache.h"
-#include "linux-nat.h"
-#include "amd64-linux-tdep.h"
-
-#include "gdb_assert.h"
-#include "gdb_string.h"
-#include <sys/ptrace.h>
-#include <sys/debugreg.h>
-#include <sys/syscall.h>
-#include <sys/procfs.h>
+#include "elf/common.h"
+#include <sys/uio.h>
+#include "nat/gdb_ptrace.h"
#include <asm/prctl.h>
-/* FIXME ezannoni-2003-07-09: we need <sys/reg.h> to be included after
- <asm/ptrace.h> because the latter redefines FS and GS for no apparent
- reason, and those definitions don't match the ones that libpthread_db
- uses, which come from <sys/reg.h>. */
-/* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have
- been removed from ptrace.h in the kernel. However, better safe than
- sorry. */
-#include <asm/ptrace.h>
#include <sys/reg.h>
-#include "gdb_proc_service.h"
-
-/* Prototypes for supply_gregset etc. */
#include "gregset.h"
+#include "gdb_proc_service.h"
+#include "amd64-nat.h"
#include "amd64-tdep.h"
+#include "amd64-linux-tdep.h"
#include "i386-linux-tdep.h"
-#include "amd64-nat.h"
+#include "gdbsupport/x86-xstate.h"
-/* Mapping between the general-purpose registers in GNU/Linux x86-64
- `struct user' format and GDB's register cache layout. */
+#include "x86-linux-nat.h"
+#include "nat/linux-ptrace.h"
+#include "nat/amd64-linux-siginfo.h"
-static int amd64_linux_gregset64_reg_offset[] =
+/* This definition comes from prctl.h. Kernels older than 2.5.64
+ do not have it. */
+#ifndef PTRACE_ARCH_PRCTL
+#define PTRACE_ARCH_PRCTL 30
+#endif
+
+struct amd64_linux_nat_target final : public x86_linux_nat_target
{
- RAX * 8, RBX * 8, /* %rax, %rbx */
- RCX * 8, RDX * 8, /* %rcx, %rdx */
- RSI * 8, RDI * 8, /* %rsi, %rdi */
- RBP * 8, RSP * 8, /* %rbp, %rsp */
- R8 * 8, R9 * 8, /* %r8 ... */
- R10 * 8, R11 * 8,
- R12 * 8, R13 * 8,
- R14 * 8, R15 * 8, /* ... %r15 */
- RIP * 8, EFLAGS * 8, /* %rip, %eflags */
- CS * 8, SS * 8, /* %cs, %ss */
- DS * 8, ES * 8, /* %ds, %es */
- FS * 8, GS * 8, /* %fs, %gs */
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1,
- ORIG_RAX * 8
+ /* Add our register access methods. */
+ void fetch_registers (struct regcache *, int) override;
+ void store_registers (struct regcache *, int) override;
+
+ bool low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, int direction)
+ override;
};
-\f
+
+static amd64_linux_nat_target the_amd64_linux_nat_target;
/* Mapping between the general-purpose registers in GNU/Linux x86-64
`struct user' format and GDB's register cache layout for GNU/Linux
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1,
- ORIG_RAX * 8 /* "orig_eax" */
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
+ -1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
+ -1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
+ -1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
+ -1, /* PKEYS register PKRU */
+ ORIG_RAX * 8 /* "orig_eax" */
};
\f
/* Transfering the general-purpose registers between GDB, inferiors
and core files. */
+/* See amd64_collect_native_gregset. This linux specific version handles
+ issues with negative EAX values not being restored correctly upon syscall
+ return when debugging 32-bit targets. It has no effect on 64-bit
+ targets. */
+
+static void
+amd64_linux_collect_native_gregset (const struct regcache *regcache,
+ void *gregs, int regnum)
+{
+ amd64_collect_native_gregset (regcache, gregs, regnum);
+
+ struct gdbarch *gdbarch = regcache->arch ();
+ if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
+ {
+ /* Sign extend EAX value to avoid potential syscall restart
+ problems.
+
+ On Linux, when a syscall is interrupted by a signal, the
+ (kernel function implementing the) syscall may return
+ -ERESTARTSYS when a signal occurs. Doing so indicates that
+ the syscall is restartable. Then, depending on settings
+ associated with the signal handler, and after the signal
+ handler is called, the kernel can then either return -EINTR
+ or it can cause the syscall to be restarted. We are
+ concerned with the latter case here.
+
+ On (32-bit) i386, the status (-ERESTARTSYS) is placed in the
+ EAX register. When debugging a 32-bit process from a 64-bit
+ (amd64) GDB, the debugger fetches 64-bit registers even
+ though the process being debugged is only 32-bit. The
+ register cache is only 32 bits wide though; GDB discards the
+ high 32 bits when placing 64-bit values in the 32-bit
+ regcache. Normally, this is not a problem since the 32-bit
+ process should only care about the lower 32-bit portions of
+ these registers. That said, it can happen that the 64-bit
+ value being restored will be different from the 64-bit value
+ that was originally retrieved from the kernel. The one place
+ (that we know of) where it does matter is in the kernel's
+ syscall restart code. The kernel's code for restarting a
+ syscall after a signal expects to see a negative value
+ (specifically -ERESTARTSYS) in the 64-bit RAX register in
+ order to correctly cause a syscall to be restarted.
+
+ The call to amd64_collect_native_gregset, above, is setting
+ the high 32 bits of RAX (and other registers too) to 0. For
+ syscall restart, we need to sign extend EAX so that RAX will
+ appear as a negative value when EAX is set to -ERESTARTSYS.
+ This in turn will cause the signal handling code in the
+ kernel to recognize -ERESTARTSYS which will in turn cause the
+ syscall to be restarted.
+
+ The test case gdb.base/interrupt.exp tests for this problem.
+ Without this sign extension code in place, it'll show
+ a number of failures when testing against unix/-m32. */
+
+ if (regnum == -1 || regnum == I386_EAX_REGNUM)
+ {
+ void *ptr = ((gdb_byte *) gregs
+ + amd64_linux_gregset32_reg_offset[I386_EAX_REGNUM]);
+
+ *(int64_t *) ptr = *(int32_t *) ptr;
+ }
+ }
+}
+
/* Fill GDB's register cache with the general-purpose register values
in *GREGSETP. */
fill_gregset (const struct regcache *regcache,
elf_gregset_t *gregsetp, int regnum)
{
- amd64_collect_native_gregset (regcache, gregsetp, regnum);
+ amd64_linux_collect_native_gregset (regcache, gregsetp, regnum);
}
/* Transfering floating-point registers between GDB, inferiors and cores. */
this for all registers (including the floating point and SSE
registers). */
-static void
-amd64_linux_fetch_inferior_registers (struct regcache *regcache, int regnum)
+void
+amd64_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
{
- struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ struct gdbarch *gdbarch = regcache->arch ();
int tid;
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = regcache->ptid ().lwp ();
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = regcache->ptid ().pid (); /* Not a threaded program. */
if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum))
{
{
elf_fpregset_t fpregs;
- if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
- perror_with_name (_("Couldn't get floating point status"));
+ if (have_ptrace_getregset == TRIBOOL_TRUE)
+ {
+ char xstateregs[X86_XSTATE_MAX_SIZE];
+ struct iovec iov;
+
+ /* Pre-4.14 kernels have a bug (fixed by commit 0852b374173b
+ "x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on
+ Intel Skylake CPUs") that sometimes causes the mxcsr location in
+ xstateregs not to be copied by PTRACE_GETREGSET. Make sure that
+ the location is at least initialized with a defined value. */
+ memset (xstateregs, 0, sizeof (xstateregs));
+ iov.iov_base = xstateregs;
+ iov.iov_len = sizeof (xstateregs);
+ if (ptrace (PTRACE_GETREGSET, tid,
+ (unsigned int) NT_X86_XSTATE, (long) &iov) < 0)
+ perror_with_name (_("Couldn't get extended state status"));
+
+ amd64_supply_xsave (regcache, -1, xstateregs);
+ }
+ else
+ {
+ if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
+ perror_with_name (_("Couldn't get floating point status"));
- amd64_supply_fxsave (regcache, -1, &fpregs);
+ amd64_supply_fxsave (regcache, -1, &fpregs);
+ }
+#ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+ {
+ /* PTRACE_ARCH_PRCTL is obsolete since 2.6.25, where the
+ fs_base and gs_base fields of user_regs_struct can be
+ used directly. */
+ unsigned long base;
+
+ if (regnum == -1 || regnum == AMD64_FSBASE_REGNUM)
+ {
+ if (ptrace (PTRACE_ARCH_PRCTL, tid, &base, ARCH_GET_FS) < 0)
+ perror_with_name (_("Couldn't get segment register fs_base"));
+
+ regcache->raw_supply (AMD64_FSBASE_REGNUM, &base);
+ }
+
+ if (regnum == -1 || regnum == AMD64_GSBASE_REGNUM)
+ {
+ if (ptrace (PTRACE_ARCH_PRCTL, tid, &base, ARCH_GET_GS) < 0)
+ perror_with_name (_("Couldn't get segment register gs_base"));
+
+ regcache->raw_supply (AMD64_GSBASE_REGNUM, &base);
+ }
+ }
+#endif
}
}
-1, do this for all registers (including the floating-point and SSE
registers). */
-static void
-amd64_linux_store_inferior_registers (struct regcache *regcache, int regnum)
+void
+amd64_linux_nat_target::store_registers (struct regcache *regcache, int regnum)
{
- struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ struct gdbarch *gdbarch = regcache->arch ();
int tid;
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = regcache->ptid ().lwp ();
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = regcache->ptid ().pid (); /* Not a threaded program. */
if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum))
{
if (ptrace (PTRACE_GETREGS, tid, 0, (long) ®s) < 0)
perror_with_name (_("Couldn't get registers"));
- amd64_collect_native_gregset (regcache, ®s, regnum);
+ amd64_linux_collect_native_gregset (regcache, ®s, regnum);
if (ptrace (PTRACE_SETREGS, tid, 0, (long) ®s) < 0)
perror_with_name (_("Couldn't write registers"));
{
elf_fpregset_t fpregs;
- if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
- perror_with_name (_("Couldn't get floating point status"));
+ if (have_ptrace_getregset == TRIBOOL_TRUE)
+ {
+ char xstateregs[X86_XSTATE_MAX_SIZE];
+ struct iovec iov;
- amd64_collect_fxsave (regcache, regnum, &fpregs);
+ iov.iov_base = xstateregs;
+ iov.iov_len = sizeof (xstateregs);
+ if (ptrace (PTRACE_GETREGSET, tid,
+ (unsigned int) NT_X86_XSTATE, (long) &iov) < 0)
+ perror_with_name (_("Couldn't get extended state status"));
- if (ptrace (PTRACE_SETFPREGS, tid, 0, (long) &fpregs) < 0)
- perror_with_name (_("Couldn't write floating point status"));
+ amd64_collect_xsave (regcache, regnum, xstateregs, 0);
- return;
- }
-}
-\f
-/* Support for debug registers. */
+ if (ptrace (PTRACE_SETREGSET, tid,
+ (unsigned int) NT_X86_XSTATE, (long) &iov) < 0)
+ perror_with_name (_("Couldn't write extended state status"));
+ }
+ else
+ {
+ if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
+ perror_with_name (_("Couldn't get floating point status"));
-static unsigned long amd64_linux_dr[DR_CONTROL + 1];
+ amd64_collect_fxsave (regcache, regnum, &fpregs);
-static unsigned long
-amd64_linux_dr_get (ptid_t ptid, int regnum)
-{
- int tid;
- unsigned long value;
+ if (ptrace (PTRACE_SETFPREGS, tid, 0, (long) &fpregs) < 0)
+ perror_with_name (_("Couldn't write floating point status"));
+ }
- tid = TIDGET (ptid);
- if (tid == 0)
- tid = PIDGET (ptid);
-
- /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
- ptrace call fails breaks debugging remote targets. The correct
- way to fix this is to add the hardware breakpoint and watchpoint
- stuff to the target vector. For now, just return zero if the
- ptrace call fails. */
- errno = 0;
- value = ptrace (PTRACE_PEEKUSER, tid,
- offsetof (struct user, u_debugreg[regnum]), 0);
- if (errno != 0)
-#if 0
- perror_with_name (_("Couldn't read debug register"));
-#else
- return 0;
+#ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+ {
+ /* PTRACE_ARCH_PRCTL is obsolete since 2.6.25, where the
+ fs_base and gs_base fields of user_regs_struct can be
+ used directly. */
+ void *base;
+
+ if (regnum == -1 || regnum == AMD64_FSBASE_REGNUM)
+ {
+ regcache->raw_collect (AMD64_FSBASE_REGNUM, &base);
+
+ if (ptrace (PTRACE_ARCH_PRCTL, tid, base, ARCH_SET_FS) < 0)
+ perror_with_name (_("Couldn't write segment register fs_base"));
+ }
+ if (regnum == -1 || regnum == AMD64_GSBASE_REGNUM)
+ {
+
+ regcache->raw_collect (AMD64_GSBASE_REGNUM, &base);
+ if (ptrace (PTRACE_ARCH_PRCTL, tid, base, ARCH_SET_GS) < 0)
+ perror_with_name (_("Couldn't write segment register gs_base"));
+ }
+ }
#endif
-
- return value;
-}
-
-static void
-amd64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
-{
- int tid;
-
- tid = TIDGET (ptid);
- if (tid == 0)
- tid = PIDGET (ptid);
-
- errno = 0;
- ptrace (PTRACE_POKEUSER, tid,
- offsetof (struct user, u_debugreg[regnum]), value);
- if (errno != 0)
- perror_with_name (_("Couldn't write debug register"));
-}
-
-void
-amd64_linux_dr_set_control (unsigned long control)
-{
- struct lwp_info *lp;
- ptid_t ptid;
-
- amd64_linux_dr[DR_CONTROL] = control;
- ALL_LWPS (lp, ptid)
- amd64_linux_dr_set (ptid, DR_CONTROL, control);
-}
-
-void
-amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
-{
- struct lwp_info *lp;
- ptid_t ptid;
-
- gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
-
- amd64_linux_dr[DR_FIRSTADDR + regnum] = addr;
- ALL_LWPS (lp, ptid)
- amd64_linux_dr_set (ptid, DR_FIRSTADDR + regnum, addr);
-}
-
-void
-amd64_linux_dr_reset_addr (int regnum)
-{
- amd64_linux_dr_set_addr (regnum, 0);
-}
-
-unsigned long
-amd64_linux_dr_get_status (void)
-{
- return amd64_linux_dr_get (inferior_ptid, DR_STATUS);
-}
-
-static void
-amd64_linux_new_thread (ptid_t ptid)
-{
- int i;
-
- for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
- amd64_linux_dr_set (ptid, i, amd64_linux_dr[i]);
-
- amd64_linux_dr_set (ptid, DR_CONTROL, amd64_linux_dr[DR_CONTROL]);
+ }
}
\f
a request for a thread's local storage address. */
ps_err_e
-ps_get_thread_area (const struct ps_prochandle *ph,
+ps_get_thread_area (struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
- if (gdbarch_ptr_bit (current_gdbarch) == 32)
+ if (gdbarch_bfd_arch_info (ph->thread->inf->gdbarch)->bits_per_word == 32)
{
- /* The full structure is found in <asm-i386/ldt.h>. The second
- integer is the LDT's base_address and that is used to locate
- the thread's local storage. See i386-linux-nat.c more
- info. */
- unsigned int desc[4];
-
- /* This code assumes that "int" is 32 bits and that
- GET_THREAD_AREA returns no more than 4 int values. */
- gdb_assert (sizeof (int) == 4);
-#ifndef PTRACE_GET_THREAD_AREA
-#define PTRACE_GET_THREAD_AREA 25
-#endif
- if (ptrace (PTRACE_GET_THREAD_AREA,
- lwpid, (void *) (long) idx, (unsigned long) &desc) < 0)
- return PS_ERR;
-
- /* Extend the value to 64 bits. Here it's assumed that a "long"
- and a "void *" are the same. */
- (*base) = (void *) (long) desc[1];
- return PS_OK;
+ unsigned int base_addr;
+ ps_err_e result;
+
+ result = x86_linux_get_thread_area (lwpid, (void *) (long) idx,
+ &base_addr);
+ if (result == PS_OK)
+ {
+ /* Extend the value to 64 bits. Here it's assumed that
+ a "long" and a "void *" are the same. */
+ (*base) = (void *) (long) base_addr;
+ }
+ return result;
}
else
{
- /* This definition comes from prctl.h, but some kernels may not
- have it. */
-#ifndef PTRACE_ARCH_PRCTL
-#define PTRACE_ARCH_PRCTL 30
-#endif
+
/* FIXME: ezannoni-2003-07-09 see comment above about include
file order. We could be getting bogus values for these two. */
gdb_assert (FS < ELF_NGREG);
switch (idx)
{
case FS:
+#ifdef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+ {
+ /* PTRACE_ARCH_PRCTL is obsolete since 2.6.25, where the
+ fs_base and gs_base fields of user_regs_struct can be
+ used directly. */
+ unsigned long fs;
+ errno = 0;
+ fs = ptrace (PTRACE_PEEKUSER, lwpid,
+ offsetof (struct user_regs_struct, fs_base), 0);
+ if (errno == 0)
+ {
+ *base = (void *) fs;
+ return PS_OK;
+ }
+ }
+#endif
if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
return PS_OK;
break;
case GS:
+#ifdef HAVE_STRUCT_USER_REGS_STRUCT_GS_BASE
+ {
+ unsigned long gs;
+ errno = 0;
+ gs = ptrace (PTRACE_PEEKUSER, lwpid,
+ offsetof (struct user_regs_struct, gs_base), 0);
+ if (errno == 0)
+ {
+ *base = (void *) gs;
+ return PS_OK;
+ }
+ }
+#endif
if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
return PS_OK;
break;
}
\f
-static void (*super_post_startup_inferior) (ptid_t ptid);
+/* Convert a ptrace/host siginfo object, into/from the siginfo in the
+ layout of the inferiors' architecture. Returns true if any
+ conversion was done; false otherwise. If DIRECTION is 1, then copy
+ from INF to PTRACE. If DIRECTION is 0, copy from PTRACE to
+ INF. */
-static void
-amd64_linux_child_post_startup_inferior (ptid_t ptid)
+bool
+amd64_linux_nat_target::low_siginfo_fixup (siginfo_t *ptrace,
+ gdb_byte *inf,
+ int direction)
{
- i386_cleanup_dregs ();
- super_post_startup_inferior (ptid);
+ struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
+
+ /* Is the inferior 32-bit? If so, then do fixup the siginfo
+ object. */
+ if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
+ return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
+ FIXUP_32);
+ /* No fixup for native x32 GDB. */
+ else if (gdbarch_addr_bit (gdbarch) == 32 && sizeof (void *) == 8)
+ return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
+ FIXUP_X32);
+ else
+ return false;
}
-\f
-
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_amd64_linux_nat (void);
void
_initialize_amd64_linux_nat (void)
{
- struct target_ops *t;
-
amd64_native_gregset32_reg_offset = amd64_linux_gregset32_reg_offset;
amd64_native_gregset32_num_regs = I386_LINUX_NUM_REGS;
- amd64_native_gregset64_reg_offset = amd64_linux_gregset64_reg_offset;
+ amd64_native_gregset64_reg_offset = amd64_linux_gregset_reg_offset;
amd64_native_gregset64_num_regs = AMD64_LINUX_NUM_REGS;
gdb_assert (ARRAY_SIZE (amd64_linux_gregset32_reg_offset)
== amd64_native_gregset32_num_regs);
- gdb_assert (ARRAY_SIZE (amd64_linux_gregset64_reg_offset)
- == amd64_native_gregset64_num_regs);
-
- /* Fill in the generic GNU/Linux methods. */
- t = linux_target ();
- i386_use_watchpoints (t);
-
- /* Override the GNU/Linux inferior startup hook. */
- super_post_startup_inferior = t->to_post_startup_inferior;
- t->to_post_startup_inferior = amd64_linux_child_post_startup_inferior;
-
- /* Add our register access methods. */
- t->to_fetch_registers = amd64_linux_fetch_inferior_registers;
- t->to_store_registers = amd64_linux_store_inferior_registers;
+ linux_target = &the_amd64_linux_nat_target;
- /* Register the target. */
- linux_nat_add_target (t);
- linux_nat_set_new_thread (t, amd64_linux_new_thread);
+ /* Add the target. */
+ add_inf_child_target (linux_target);
}
projects / deliverable / binutils-gdb.git / blobdiff