On Sun, 12 Apr 2020 at 08:19, Vincent Chen <vincent.c...@sifive.com> wrote:
>
> The skeleton of RISC-V KGDB port.
>
> Signed-off-by: Vincent Chen <vincent.c...@sifive.com>
> Reviewed-by: Palmer Dabbelt <palmerdabb...@google.com>
> ---
> arch/riscv/Kconfig | 1 +
> arch/riscv/include/asm/kdebug.h | 12 +++
> arch/riscv/include/asm/kgdb.h | 107 +++++++++++++++++++++
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/kgdb.c | 200
> ++++++++++++++++++++++++++++++++++++++++
> arch/riscv/kernel/traps.c | 5 +
> 6 files changed, 326 insertions(+)
> create mode 100644 arch/riscv/include/asm/kdebug.h
> create mode 100644 arch/riscv/include/asm/kgdb.h
> create mode 100644 arch/riscv/kernel/kgdb.c
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index a197258595ef..7db9a81cda75 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -68,6 +68,7 @@ config RISCV
> select ARCH_HAS_GCOV_PROFILE_ALL
> select HAVE_COPY_THREAD_TLS
> select HAVE_ARCH_KASAN if MMU && 64BIT
> + select HAVE_ARCH_KGDB
>
> config ARCH_MMAP_RND_BITS_MIN
> default 18 if 64BIT
> diff --git a/arch/riscv/include/asm/kdebug.h b/arch/riscv/include/asm/kdebug.h
> new file mode 100644
> index 000000000000..85ac00411f6e
> --- /dev/null
> +++ b/arch/riscv/include/asm/kdebug.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef _ASM_ARC_KDEBUG_H
> +#define _ASM_ARC_KDEBUG_H
> +
> +enum die_val {
> + DIE_UNUSED,
> + DIE_TRAP,
> + DIE_OOPS
> +};
> +
> +#endif
> diff --git a/arch/riscv/include/asm/kgdb.h b/arch/riscv/include/asm/kgdb.h
> new file mode 100644
> index 000000000000..69bc6a03081d
> --- /dev/null
> +++ b/arch/riscv/include/asm/kgdb.h
> @@ -0,0 +1,107 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef __ASM_KGDB_H_
> +#define __ASM_KGDB_H_
> +
> +#ifdef __KERNEL__
> +
> +#define GDB_SIZEOF_REG sizeof(unsigned long)
> +
> +#define DBG_MAX_REG_NUM (33)
> +#define NUMREGBYTES ((DBG_MAX_REG_NUM) * GDB_SIZEOF_REG)
> +#define CACHE_FLUSH_IS_SAFE 1
[...]
> +#define BUFMAX 2048
> +#ifdef CONFIG_RISCV_ISA_C
> +#define BREAK_INSTR_SIZE 2
> +#else
> +#define BREAK_INSTR_SIZE 4
> +#endif
> +#define CACHE_FLUSH_IS_SAFE 1
double macro definition?
-Sumit
> +
> +#ifndef __ASSEMBLY__
> +
> +extern int kgdb_has_hit_break(unsigned long addr);
> +extern unsigned long kgdb_compiled_break;
> +
> +static inline void arch_kgdb_breakpoint(void)
> +{
> + asm(".global kgdb_compiled_break\n"
> + ".option norvc\n"
> + "kgdb_compiled_break: ebreak\n"
> + ".option rvc\n");
> +}
> +
> +#endif /* !__ASSEMBLY__ */
> +
> +#define DBG_REG_ZERO "zero"
> +#define DBG_REG_RA "ra"
> +#define DBG_REG_SP "sp"
> +#define DBG_REG_GP "gp"
> +#define DBG_REG_TP "tp"
> +#define DBG_REG_T0 "t0"
> +#define DBG_REG_T1 "t1"
> +#define DBG_REG_T2 "t2"
> +#define DBG_REG_FP "fp"
> +#define DBG_REG_S1 "s1"
> +#define DBG_REG_A0 "a0"
> +#define DBG_REG_A1 "a1"
> +#define DBG_REG_A2 "a2"
> +#define DBG_REG_A3 "a3"
> +#define DBG_REG_A4 "a4"
> +#define DBG_REG_A5 "a5"
> +#define DBG_REG_A6 "a6"
> +#define DBG_REG_A7 "a7"
> +#define DBG_REG_S2 "s2"
> +#define DBG_REG_S3 "s3"
> +#define DBG_REG_S4 "s4"
> +#define DBG_REG_S5 "s5"
> +#define DBG_REG_S6 "s6"
> +#define DBG_REG_S7 "s7"
> +#define DBG_REG_S8 "s8"
> +#define DBG_REG_S9 "s9"
> +#define DBG_REG_S10 "s10"
> +#define DBG_REG_S11 "s11"
> +#define DBG_REG_T3 "t3"
> +#define DBG_REG_T4 "t4"
> +#define DBG_REG_T5 "t5"
> +#define DBG_REG_T6 "t6"
> +#define DBG_REG_EPC "pc"
> +
> +#define DBG_REG_ZERO_OFF 0
> +#define DBG_REG_RA_OFF 1
> +#define DBG_REG_SP_OFF 2
> +#define DBG_REG_GP_OFF 3
> +#define DBG_REG_TP_OFF 4
> +#define DBG_REG_T0_OFF 5
> +#define DBG_REG_T1_OFF 6
> +#define DBG_REG_T2_OFF 7
> +#define DBG_REG_FP_OFF 8
> +#define DBG_REG_S1_OFF 9
> +#define DBG_REG_A0_OFF 10
> +#define DBG_REG_A1_OFF 11
> +#define DBG_REG_A2_OFF 12
> +#define DBG_REG_A3_OFF 13
> +#define DBG_REG_A4_OFF 14
> +#define DBG_REG_A5_OFF 15
> +#define DBG_REG_A6_OFF 16
> +#define DBG_REG_A7_OFF 17
> +#define DBG_REG_S2_OFF 18
> +#define DBG_REG_S3_OFF 19
> +#define DBG_REG_S4_OFF 20
> +#define DBG_REG_S5_OFF 21
> +#define DBG_REG_S6_OFF 22
> +#define DBG_REG_S7_OFF 23
> +#define DBG_REG_S8_OFF 24
> +#define DBG_REG_S9_OFF 25
> +#define DBG_REG_S10_OFF 26
> +#define DBG_REG_S11_OFF 27
> +#define DBG_REG_T3_OFF 28
> +#define DBG_REG_T4_OFF 29
> +#define DBG_REG_T5_OFF 30
> +#define DBG_REG_T6_OFF 31
> +#define DBG_REG_EPC_OFF 32
> +#define DBG_REG_STATUS_OFF 33
> +#define DBG_REG_BADADDR_OFF 34
> +#define DBG_REG_CAUSE_OFF 35
> +#endif
> +#endif
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 86c83081044f..1f5736e996fd 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -51,5 +51,6 @@ ifeq ($(CONFIG_RISCV_SBI), y)
> obj-$(CONFIG_SMP) += cpu_ops_sbi.o
> endif
> obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o
> +obj-$(CONFIG_KGDB) += kgdb.o
>
> clean:
> diff --git a/arch/riscv/kernel/kgdb.c b/arch/riscv/kernel/kgdb.c
> new file mode 100644
> index 000000000000..6bdc0908a5b8
> --- /dev/null
> +++ b/arch/riscv/kernel/kgdb.c
> @@ -0,0 +1,200 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2020 SiFive
> + */
> +
> +#include <linux/ptrace.h>
> +#include <linux/kdebug.h>
> +#include <linux/bug.h>
> +#include <linux/kgdb.h>
> +#include <linux/irqflags.h>
> +#include <linux/string.h>
> +#include <asm/cacheflush.h>
> +
> +enum {
> + NOT_KGDB_BREAK = 0,
> + KGDB_SW_BREAK,
> + KGDB_COMPILED_BREAK,
> +};
> +
> +struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
> + {DBG_REG_ZERO, GDB_SIZEOF_REG, -1},
> + {DBG_REG_RA, GDB_SIZEOF_REG, offsetof(struct pt_regs, ra)},
> + {DBG_REG_SP, GDB_SIZEOF_REG, offsetof(struct pt_regs, sp)},
> + {DBG_REG_GP, GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
> + {DBG_REG_TP, GDB_SIZEOF_REG, offsetof(struct pt_regs, tp)},
> + {DBG_REG_T0, GDB_SIZEOF_REG, offsetof(struct pt_regs, t0)},
> + {DBG_REG_T1, GDB_SIZEOF_REG, offsetof(struct pt_regs, t1)},
> + {DBG_REG_T2, GDB_SIZEOF_REG, offsetof(struct pt_regs, t2)},
> + {DBG_REG_FP, GDB_SIZEOF_REG, offsetof(struct pt_regs, s0)},
> + {DBG_REG_S1, GDB_SIZEOF_REG, offsetof(struct pt_regs, a1)},
> + {DBG_REG_A0, GDB_SIZEOF_REG, offsetof(struct pt_regs, a0)},
> + {DBG_REG_A1, GDB_SIZEOF_REG, offsetof(struct pt_regs, a1)},
> + {DBG_REG_A2, GDB_SIZEOF_REG, offsetof(struct pt_regs, a2)},
> + {DBG_REG_A3, GDB_SIZEOF_REG, offsetof(struct pt_regs, a3)},
> + {DBG_REG_A4, GDB_SIZEOF_REG, offsetof(struct pt_regs, a4)},
> + {DBG_REG_A5, GDB_SIZEOF_REG, offsetof(struct pt_regs, a5)},
> + {DBG_REG_A6, GDB_SIZEOF_REG, offsetof(struct pt_regs, a6)},
> + {DBG_REG_A7, GDB_SIZEOF_REG, offsetof(struct pt_regs, a7)},
> + {DBG_REG_S2, GDB_SIZEOF_REG, offsetof(struct pt_regs, s2)},
> + {DBG_REG_S3, GDB_SIZEOF_REG, offsetof(struct pt_regs, s3)},
> + {DBG_REG_S4, GDB_SIZEOF_REG, offsetof(struct pt_regs, s4)},
> + {DBG_REG_S5, GDB_SIZEOF_REG, offsetof(struct pt_regs, s5)},
> + {DBG_REG_S6, GDB_SIZEOF_REG, offsetof(struct pt_regs, s6)},
> + {DBG_REG_S7, GDB_SIZEOF_REG, offsetof(struct pt_regs, s7)},
> + {DBG_REG_S8, GDB_SIZEOF_REG, offsetof(struct pt_regs, s8)},
> + {DBG_REG_S9, GDB_SIZEOF_REG, offsetof(struct pt_regs, s9)},
> + {DBG_REG_S10, GDB_SIZEOF_REG, offsetof(struct pt_regs, s10)},
> + {DBG_REG_S11, GDB_SIZEOF_REG, offsetof(struct pt_regs, s11)},
> + {DBG_REG_T3, GDB_SIZEOF_REG, offsetof(struct pt_regs, t3)},
> + {DBG_REG_T4, GDB_SIZEOF_REG, offsetof(struct pt_regs, t4)},
> + {DBG_REG_T5, GDB_SIZEOF_REG, offsetof(struct pt_regs, t5)},
> + {DBG_REG_T6, GDB_SIZEOF_REG, offsetof(struct pt_regs, t6)},
> + {DBG_REG_EPC, GDB_SIZEOF_REG, offsetof(struct pt_regs, epc)},
> +};
> +
> +char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
> +{
> + if (regno >= DBG_MAX_REG_NUM || regno < 0)
> + return NULL;
> +
> + if (dbg_reg_def[regno].offset != -1)
> + memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
> + dbg_reg_def[regno].size);
> + else
> + memset(mem, 0, dbg_reg_def[regno].size);
> + return dbg_reg_def[regno].name;
> +}
> +
> +int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
> +{
> + if (regno >= DBG_MAX_REG_NUM || regno < 0)
> + return -EINVAL;
> +
> + if (dbg_reg_def[regno].offset != -1)
> + memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
> + dbg_reg_def[regno].size);
> + return 0;
> +}
> +
> +void
> +sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct
> *task)
> +{
> + /* Initialize to zero */
> + memset((char *)gdb_regs, 0, NUMREGBYTES);
> +
> + gdb_regs[DBG_REG_SP_OFF] = task->thread.sp;
> + gdb_regs[DBG_REG_FP_OFF] = task->thread.s[0];
> + gdb_regs[DBG_REG_S1_OFF] = task->thread.s[1];
> + gdb_regs[DBG_REG_S2_OFF] = task->thread.s[2];
> + gdb_regs[DBG_REG_S3_OFF] = task->thread.s[3];
> + gdb_regs[DBG_REG_S4_OFF] = task->thread.s[4];
> + gdb_regs[DBG_REG_S5_OFF] = task->thread.s[5];
> + gdb_regs[DBG_REG_S6_OFF] = task->thread.s[6];
> + gdb_regs[DBG_REG_S7_OFF] = task->thread.s[7];
> + gdb_regs[DBG_REG_S8_OFF] = task->thread.s[8];
> + gdb_regs[DBG_REG_S9_OFF] = task->thread.s[10];
> + gdb_regs[DBG_REG_S10_OFF] = task->thread.s[11];
> + gdb_regs[DBG_REG_EPC_OFF] = task->thread.ra;
> +}
> +
> +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
> +{
> + regs->epc = pc;
> +}
> +
> +static inline void kgdb_arch_update_addr(struct pt_regs *regs,
> + char *remcom_in_buffer)
> +{
> + unsigned long addr;
> + char *ptr;
> +
> + ptr = &remcom_in_buffer[1];
> + if (kgdb_hex2long(&ptr, &addr))
> + regs->epc = addr;
> +}
> +
> +int kgdb_arch_handle_exception(int vector, int signo, int err_code,
> + char *remcom_in_buffer, char
> *remcom_out_buffer,
> + struct pt_regs *regs)
> +{
> + int err = 0;
> +
> + switch (remcom_in_buffer[0]) {
> + case 'c':
> + case 'D':
> + case 'k':
> + if (remcom_in_buffer[0] == 'c')
> + kgdb_arch_update_addr(regs, remcom_in_buffer);
> + break;
> + default:
> + err = -1;
> + }
> +
> + return err;
> +}
> +
> +int kgdb_riscv_kgdbbreak(unsigned long addr)
> +{
> + if (atomic_read(&kgdb_setting_breakpoint))
> + if (addr == (unsigned long)&kgdb_compiled_break)
> + return KGDB_COMPILED_BREAK;
> +
> + return kgdb_has_hit_break(addr);
> +}
> +
> +static int kgdb_riscv_notify(struct notifier_block *self, unsigned long cmd,
> + void *ptr)
> +{
> + struct die_args *args = (struct die_args *)ptr;
> + struct pt_regs *regs = args->regs;
> + unsigned long flags;
> + int type;
> +
> + if (user_mode(regs))
> + return NOTIFY_DONE;
> +
> + type = kgdb_riscv_kgdbbreak(regs->epc);
> + if (type == NOT_KGDB_BREAK && cmd == DIE_TRAP)
> + return NOTIFY_DONE;
> +
> + local_irq_save(flags);
> + if (kgdb_handle_exception(1, args->signr, cmd, regs))
> + return NOTIFY_DONE;
> +
> + if (type == KGDB_COMPILED_BREAK)
> + regs->epc += 4;
> +
> + local_irq_restore(flags);
> +
> + return NOTIFY_STOP;
> +}
> +
> +static struct notifier_block kgdb_notifier = {
> + .notifier_call = kgdb_riscv_notify,
> +};
> +
> +int kgdb_arch_init(void)
> +{
> + register_die_notifier(&kgdb_notifier);
> +
> + return 0;
> +}
> +
> +void kgdb_arch_exit(void)
> +{
> + unregister_die_notifier(&kgdb_notifier);
> +}
> +
> +/*
> + * Global data
> + */
> +#ifdef CONFIG_RISCV_ISA_C
> +const struct kgdb_arch arch_kgdb_ops = {
> + .gdb_bpt_instr = {0x02, 0x90}, /* c.ebreak */
> +};
> +#else
> +const struct kgdb_arch arch_kgdb_ops = {
> + .gdb_bpt_instr = {0x73, 0x00, 0x10, 0x00}, /* ebreak */
> +};
> +#endif
> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> index 7f58fa53033f..5080fdf8c296 100644
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -147,6 +147,11 @@ asmlinkage __visible void do_trap_break(struct pt_regs
> *regs)
> {
> if (user_mode(regs))
> force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user
> *)regs->epc);
> +#ifdef CONFIG_KGDB
> + else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
> + ==
> NOTIFY_STOP)
> + return;
> +#endif
> else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN)
> regs->epc += get_break_insn_length(regs->epc);
> else
> --
> 2.7.4
>
>
>
> _______________________________________________
> Kgdb-bugreport mailing list
> Kgdb-bugreport@lists.sourceforge.net
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