| /* Native-dependent code for GNU/Linux x86 (i386 and x86-64). |
| |
| Copyright (C) 1999-2024 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 "inferior.h" |
| #include "elf/common.h" |
| #include "gdb_proc_service.h" |
| #include "nat/gdb_ptrace.h" |
| #include <sys/user.h> |
| #include <sys/procfs.h> |
| #include <sys/uio.h> |
| |
| #include "x86-nat.h" |
| #ifndef __x86_64__ |
| #include "nat/i386-linux.h" |
| #endif |
| #include "x86-linux-nat.h" |
| #include "i386-linux-tdep.h" |
| #ifdef __x86_64__ |
| #include "amd64-linux-tdep.h" |
| #endif |
| #include "gdbsupport/x86-xstate.h" |
| #include "nat/x86-xstate.h" |
| #include "nat/linux-btrace.h" |
| #include "nat/linux-nat.h" |
| #include "nat/x86-linux.h" |
| #include "nat/x86-linux-dregs.h" |
| #include "nat/linux-ptrace.h" |
| #include "nat/x86-linux-tdesc.h" |
| |
| /* linux_nat_target::low_new_fork implementation. */ |
| |
| void |
| x86_linux_nat_target::low_new_fork (struct lwp_info *parent, pid_t child_pid) |
| { |
| pid_t parent_pid; |
| struct x86_debug_reg_state *parent_state; |
| struct x86_debug_reg_state *child_state; |
| |
| /* NULL means no watchpoint has ever been set in the parent. In |
| that case, there's nothing to do. */ |
| if (parent->arch_private == NULL) |
| return; |
| |
| /* Linux kernel before 2.6.33 commit |
| 72f674d203cd230426437cdcf7dd6f681dad8b0d |
| will inherit hardware debug registers from parent |
| on fork/vfork/clone. Newer Linux kernels create such tasks with |
| zeroed debug registers. |
| |
| GDB core assumes the child inherits the watchpoints/hw |
| breakpoints of the parent, and will remove them all from the |
| forked off process. Copy the debug registers mirrors into the |
| new process so that all breakpoints and watchpoints can be |
| removed together. The debug registers mirror will become zeroed |
| in the end before detaching the forked off process, thus making |
| this compatible with older Linux kernels too. */ |
| |
| parent_pid = parent->ptid.pid (); |
| parent_state = x86_debug_reg_state (parent_pid); |
| child_state = x86_debug_reg_state (child_pid); |
| *child_state = *parent_state; |
| } |
| |
| |
| x86_linux_nat_target::~x86_linux_nat_target () |
| { |
| } |
| |
| /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
| |
| void |
| x86_linux_nat_target::post_startup_inferior (ptid_t ptid) |
| { |
| x86_cleanup_dregs (); |
| linux_nat_target::post_startup_inferior (ptid); |
| } |
| |
| /* Get Linux/x86 target description from running target. */ |
| |
| const struct target_desc * |
| x86_linux_nat_target::read_description () |
| { |
| /* The x86_linux_tdesc_for_tid call only reads xcr0 the first time it is |
| called, the xcr0 value is stored here and reused on subsequent calls. */ |
| static uint64_t xcr0_storage; |
| |
| if (inferior_ptid == null_ptid) |
| return this->beneath ()->read_description (); |
| |
| int tid = inferior_ptid.pid (); |
| |
| return x86_linux_tdesc_for_tid (tid, &xcr0_storage, &this->m_xsave_layout); |
| } |
| |
| |
| /* Enable branch tracing. */ |
| |
| struct btrace_target_info * |
| x86_linux_nat_target::enable_btrace (thread_info *tp, |
| const struct btrace_config *conf) |
| { |
| struct btrace_target_info *tinfo = nullptr; |
| ptid_t ptid = tp->ptid; |
| try |
| { |
| tinfo = linux_enable_btrace (ptid, conf); |
| } |
| catch (const gdb_exception_error &exception) |
| { |
| error (_("Could not enable branch tracing for %s: %s"), |
| target_pid_to_str (ptid).c_str (), exception.what ()); |
| } |
| |
| return tinfo; |
| } |
| |
| /* Disable branch tracing. */ |
| |
| void |
| x86_linux_nat_target::disable_btrace (struct btrace_target_info *tinfo) |
| { |
| enum btrace_error errcode = linux_disable_btrace (tinfo); |
| |
| if (errcode != BTRACE_ERR_NONE) |
| error (_("Could not disable branch tracing.")); |
| } |
| |
| /* Teardown branch tracing. */ |
| |
| void |
| x86_linux_nat_target::teardown_btrace (struct btrace_target_info *tinfo) |
| { |
| /* Ignore errors. */ |
| linux_disable_btrace (tinfo); |
| } |
| |
| enum btrace_error |
| x86_linux_nat_target::read_btrace (struct btrace_data *data, |
| struct btrace_target_info *btinfo, |
| enum btrace_read_type type) |
| { |
| return linux_read_btrace (data, btinfo, type); |
| } |
| |
| /* See to_btrace_conf in target.h. */ |
| |
| const struct btrace_config * |
| x86_linux_nat_target::btrace_conf (const struct btrace_target_info *btinfo) |
| { |
| return linux_btrace_conf (btinfo); |
| } |
| |
| |
| |
| /* Helper for ps_get_thread_area. Sets BASE_ADDR to a pointer to |
| the thread local storage (or its descriptor) and returns PS_OK |
| on success. Returns PS_ERR on failure. */ |
| |
| ps_err_e |
| x86_linux_get_thread_area (pid_t pid, void *addr, unsigned int *base_addr) |
| { |
| /* NOTE: cagney/2003-08-26: The definition of this buffer is found |
| in the kernel header <asm-i386/ldt.h>. It, after padding, is 4 x |
| 4 byte integers in size: `entry_number', `base_addr', `limit', |
| and a bunch of status bits. |
| |
| The values returned by this ptrace call should be part of the |
| regcache buffer, and ps_get_thread_area should channel its |
| request through the regcache. That way remote targets could |
| provide the value using the remote protocol and not this direct |
| call. |
| |
| Is this function needed? I'm guessing that the `base' is the |
| address of a descriptor that libthread_db uses to find the |
| thread local address base that GDB needs. Perhaps that |
| descriptor is defined by the ABI. Anyway, given that |
| libthread_db calls this function without prompting (gdb |
| requesting tls base) I guess it needs info in there anyway. */ |
| 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, pid, addr, &desc) < 0) |
| return PS_ERR; |
| |
| *base_addr = desc[1]; |
| return PS_OK; |
| } |
| |
| |
| void _initialize_x86_linux_nat (); |
| void |
| _initialize_x86_linux_nat () |
| { |
| /* Initialize the debug register function vectors. */ |
| x86_dr_low.set_control = x86_linux_dr_set_control; |
| x86_dr_low.set_addr = x86_linux_dr_set_addr; |
| x86_dr_low.get_addr = x86_linux_dr_get_addr; |
| x86_dr_low.get_status = x86_linux_dr_get_status; |
| x86_dr_low.get_control = x86_linux_dr_get_control; |
| x86_set_debug_register_length (sizeof (void *)); |
| } |