6ced1278fc
LoongArch defines hardware watchpoint functions for fetch operations. After the software configures the watchpoints for fetch, the processor hardware will monitor the access addresses of the fetch operations and trigger a watchpoint exception when the watchpoint setting conditions are met. Hardware watchpoints for fetch operations is used to implement hardware breakpoint function on LoongArch. Refer to the following document for hardware breakpoint. https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints A simple test is as follows: lihui@bogon:~$ cat test.c #include <stdio.h> int a = 0; int main() { printf("start test\n"); a = 1; printf("a = %d\n", a); printf("end test\n"); return 0; } lihui@bogon:~$ gcc -g test.c -o test without this patch: lihui@bogon:~$ gdb test ... (gdb) start ... Temporary breakpoint 1, main () at test.c:5 5 printf("start test\n"); (gdb) hbreak 8 No hardware breakpoint support in the target. with this patch: lihui@bogon:~$ gdb test ... (gdb) start ... Temporary breakpoint 1, main () at test.c:5 5 printf("start test\n"); (gdb) hbreak 8 Hardware assisted breakpoint 2 at 0x1200006ec: file test.c, line 8. (gdb) c Continuing. start test a = 1 Breakpoint 2, main () at test.c:8 8 printf("end test\n"); (gdb) c Continuing. end test [Inferior 1 (process 25378) exited normally] Signed-off-by: Hui Li <lihui@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
100 lines
3.1 KiB
C
100 lines
3.1 KiB
C
/* Native-dependent code for GNU/Linux on LoongArch processors.
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Copyright (C) 2024 Free Software Foundation, Inc.
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Contributed by Loongson Ltd.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "gdbsupport/common-defs.h"
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#include "gdbsupport/break-common.h"
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#include "nat/linux-nat.h"
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#include "nat/loongarch-linux-hw-point.h"
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#include "nat/loongarch-linux.h"
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#include "elf/common.h"
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#include "nat/gdb_ptrace.h"
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#include <asm/ptrace.h>
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#include <sys/uio.h>
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/* Called when resuming a thread LWP.
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The hardware debug registers are updated when there is any change. */
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void
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loongarch_linux_prepare_to_resume (struct lwp_info *lwp)
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{
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struct arch_lwp_info *info = lwp_arch_private_info (lwp);
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/* NULL means this is the main thread still going through the shell,
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or, no watchpoint has been set yet. In that case, there's
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nothing to do. */
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if (info == NULL)
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return;
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if (DR_HAS_CHANGED (info->dr_changed_bp)
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|| DR_HAS_CHANGED (info->dr_changed_wp))
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{
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ptid_t ptid = ptid_of_lwp (lwp);
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int tid = ptid.lwp ();
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struct loongarch_debug_reg_state *state
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= loongarch_get_debug_reg_state (ptid.pid ());
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if (show_debug_regs)
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debug_printf ("prepare_to_resume thread %d\n", tid);
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/* Watchpoints. */
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if (DR_HAS_CHANGED (info->dr_changed_wp))
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{
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loongarch_linux_set_debug_regs (state, tid, 1);
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DR_CLEAR_CHANGED (info->dr_changed_wp);
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}
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/* Breakpoints. */
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if (DR_HAS_CHANGED (info->dr_changed_bp))
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{
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loongarch_linux_set_debug_regs (state, tid, 0);
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DR_CLEAR_CHANGED (info->dr_changed_bp);
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}
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}
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}
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/* Function to call when a new thread is detected. */
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void
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loongarch_linux_new_thread (struct lwp_info *lwp)
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{
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ptid_t ptid = ptid_of_lwp (lwp);
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struct loongarch_debug_reg_state *state
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= loongarch_get_debug_reg_state (ptid.pid ());
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struct arch_lwp_info *info = XCNEW (struct arch_lwp_info);
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/* If there are hardware breakpoints/watchpoints in the process then mark that
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all the hardware breakpoint/watchpoint register pairs for this thread need
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to be initialized (with data from arch_process_info.debug_reg_state). */
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if (loongarch_any_set_debug_regs_state (state, false))
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DR_MARK_ALL_CHANGED (info->dr_changed_bp, loongarch_num_bp_regs);
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if (loongarch_any_set_debug_regs_state (state, true))
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DR_MARK_ALL_CHANGED (info->dr_changed_wp, loongarch_num_wp_regs);
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lwp_set_arch_private_info (lwp, info);
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}
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/* See nat/loongarch-linux.h. */
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void
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loongarch_linux_delete_thread (struct arch_lwp_info *arch_lwp)
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{
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xfree (arch_lwp);
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}
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