[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230208100837.2451-1-zhangqing@loongson.cn>
Date: Wed, 8 Feb 2023 18:08:35 +0800
From: Qing Zhang <zhangqing@...ngson.cn>
To: Huacai Chen <chenhuacai@...nel.org>,
Oleg Nesterov <oleg@...hat.com>,
WANG Xuerui <kernel@...0n.name>
Cc: Jiaxun Yang <jiaxun.yang@...goat.com>, loongarch@...ts.linux.dev,
linux-kernel@...r.kernel.org
Subject: [PATCH 0/2] LoongArch: Add hardware breakpoints/watchpoints support
Use perf framework to manage hardware instruction and data breakpoints.
LoongArch defines hardware watchpoint functions for instruction fetch
and load/store operations, after the software configures hardware watchpoints
for instruction fetch and load/store operations. The processor hardware will
monitor the access address of the instruction fetch and load/store operation,
and will trigger the exception of the watchpoint when it meets the conditions
set by the watchpoint.
The hardware monitoring points for instruction fetching and load/store operations
each have a register for the overall configuration of all monitoring points,
a register for recording the status of all monitoring points, and four registers
required for configuration of each watchpoint individually.
Watchpoint related control status register chapters:
https://github.com/loongson/LoongArch-Documentation/releases/download/2022.08.12/
LoongArch-Vol1-v1.02-CN.pdf
Initial version has the following limitations:
- userspace debug is not yet enabled: work on ptrace/gdb is in progress
- no support for virtualization
Can be tested: e.g.
1. see samples/hw_breakpoint and register_wide_hw_breakpoint.
2. ptrace(PTRACE_SINGLESTEP/..., pid, NULL, NULL)
TODO:
- Add hardware breakpoints/watchpoints for gdb, kgdb
Qing Zhang (2):
LoongArch: Add hardware breakpoints/watchpoints support
LoongArch: Add ptrace single step support
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/hw_breakpoint.h | 145 ++++++
arch/loongarch/include/asm/loongarch.h | 32 +-
arch/loongarch/include/asm/processor.h | 11 +-
arch/loongarch/include/asm/ptrace.h | 2 +
arch/loongarch/include/asm/switch_to.h | 1 +
arch/loongarch/kernel/Makefile | 1 +
arch/loongarch/kernel/hw_breakpoint.c | 525 +++++++++++++++++++++
arch/loongarch/kernel/process.c | 7 +
arch/loongarch/kernel/ptrace.c | 68 +++
arch/loongarch/kernel/traps.c | 31 +-
11 files changed, 803 insertions(+), 21 deletions(-)
create mode 100644 arch/loongarch/include/asm/hw_breakpoint.h
create mode 100644 arch/loongarch/kernel/hw_breakpoint.c
--
2.36.0
Powered by blists - more mailing lists