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path: root/arch/loongarch/kernel/hw_breakpoint.c
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2023-06-15LoongArch: Avoid uninitialized alignment_maskQing Zhang
The hardware monitoring points for instruction fetching and load/store operations need to align 4 bytes and 1/2/4/8 bytes respectively. Reported-by: Colin King <colin.i.king@gmail.com> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: ptrace: Add hardware single step supportQing Zhang
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT, PTRACE_KILL and PTRACE_SINGLESTEP handling. This implies defining arch_has_single_step() and implementing the user_enable_single_step() and user_disable_single_step() functions. LoongArch cannot do hardware single-stepping per se, the hardware single-stepping it is achieved by configuring the instruction fetch watchpoints (FWPS) and specifies that the next instruction must trigger the watch exception by setting the mask bit. In some scenarios CSR.FWPS.Skip is used to ignore the next hit result, avoid endless repeated triggering of the same watchpoint without canceling it. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: Add hardware breakpoints/watchpoints supportQing Zhang
Use perf framework to manage hardware instruction and data breakpoints. LoongArch defines hardware watchpoint functions for instruction fetch and memory load/store operations. After the software configures hardware watchpoints, the processor hardware will monitor the access address of the instruction fetch and load/store operation, and trigger an 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. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>