[PATCH v2 1/1] riscv: additional crash information

[Rick Chen]

> From: Heinrich Schuchardt [mailto:xypron.glpk at gmx.de]
> Sent: Saturday, August 01, 2020 11:16 PM
> To: Rick Jian-Zhi Chen(陳建志)
> Cc: Simon Glass; Bin Meng; Sean Anderson; u-boot at lists.denx.de; Heinrich Schuchardt
> Subject: [PATCH v2 1/1] riscv: additional crash information
>
> If an exception occurs, the relocated program counter and return address are required for an analysis.
>
> With this patch you get:
>
>     => exception undefined
>
>     Unhandled exception: Illegal instruction
>     EPC: 0000000080595908 RA: 000000008059c0c6 TVAL: 000000008030c01e
>     EPC: 0000000080007908 RA: 000000008000e0c6 reloc adjusted
>
> We can use the relocated addresses to find the involved functions in
> u.boot.map:
>
>     .text.do_undefined
>                 0x0000000080007908        0x8 cmd/built-in.o
>     .text.cmd_process
>                 0x000000008000dfcc      0x11a common/built-in.o
>                 0x000000008000dfcc                cmd_process
>
> If an exception occurs in an UEFI binary additionally the load addresses of the UEFI binaries are needed. With this patch:
>
>     => setenv efi_selftest exception
>     => bootefi selftest
>
>     Unhandled exception: Illegal instruction
>     EPC: 000000008042e18a RA: 000000008042e18a TVAL: 000000008030c01e
>     EPC: 000000007fea018a RA: 000000007fea018a reloc adjusted
>
>     UEFI image [0x0000000000000000:0xffffffffffffffff] '/\selftest'
>     UEFI image [0x000000008042e000:0x000000008042e43f] pc=0x18a '/bug.efi'
>
> The value pc=0x18a matches the position of the illegal instruction in efi_selftest_miniapp_exception.efi (loaded as /bug.efi);
>
>     asm volatile (".word 0xffffffff\n");
>
>     00000180   93 85 C5 11  1C 64 22 85  82 97 FF FF  FF FF 1C 64
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Reviewed-by: Sean Anderson <seanga2 at gmail.com>
> Tested-by: Sean Anderson <seanga2 at gmail.com>
> ---
> v2:
>         description of relocated addresses: %s/reloc/reloc adjusted/
> ---
>  arch/riscv/lib/interrupts.c | 57 +++++++++++++++++++++++--------------
>  1 file changed, 35 insertions(+), 22 deletions(-)
>
> diff --git a/arch/riscv/lib/interrupts.c b/arch/riscv/lib/interrupts.c index 074c70ee77..cd47e64487 100644
> --- a/arch/riscv/lib/interrupts.c
> +++ b/arch/riscv/lib/interrupts.c
> @@ -10,36 +10,43 @@
>   */
>
>  #include <common.h>
> +#include <efi_loader.h>
>  #include <hang.h>
>  #include <irq_func.h>
>  #include <asm/ptrace.h>
>  #include <asm/system.h>
>  #include <asm/encoding.h>
>
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +static void show_efi_loaded_images(uintptr_t epc) {
> +       efi_print_image_infos((void *)epc);
> +}
> +
>  static void show_regs(struct pt_regs *regs)  {  #ifdef CONFIG_SHOW_REGS
> -       printf("RA: " REG_FMT " SP:  " REG_FMT " GP:  " REG_FMT "\n",
> -              regs->ra, regs->sp, regs->gp);
> -       printf("TP: " REG_FMT " T0:  " REG_FMT " T1:  " REG_FMT "\n",
> -              regs->tp, regs->t0, regs->t1);
> -       printf("T2: " REG_FMT " S0:  " REG_FMT " S1:  " REG_FMT "\n",
> -              regs->t2, regs->s0, regs->s1);
> -       printf("A0: " REG_FMT " A1:  " REG_FMT " A2:  " REG_FMT "\n",
> -              regs->a0, regs->a1, regs->a2);
> -       printf("A3: " REG_FMT " A4:  " REG_FMT " A5:  " REG_FMT "\n",
> -              regs->a3, regs->a4, regs->a5);
> -       printf("A6: " REG_FMT " A7:  " REG_FMT " S2:  " REG_FMT "\n",
> -              regs->a6, regs->a7, regs->s2);
> -       printf("S3: " REG_FMT " S4:  " REG_FMT " S5:  " REG_FMT "\n",
> -              regs->s3, regs->s4, regs->s5);
> -       printf("S6: " REG_FMT " S7:  " REG_FMT " S8:  " REG_FMT "\n",
> -              regs->s6, regs->s7, regs->s8);
> -       printf("S9: " REG_FMT " S10: " REG_FMT " S11: " REG_FMT "\n",
> -              regs->s9, regs->s10, regs->s11);
> -       printf("T3: " REG_FMT " T4:  " REG_FMT " T5:  " REG_FMT "\n",
> -              regs->t3, regs->t4, regs->t5);
> -       printf("T6: " REG_FMT "\n", regs->t6);
> +       printf("SP:  " REG_FMT " GP:  " REG_FMT " TP:  " REG_FMT "\n",
> +              regs->sp, regs->gp, regs->tp);
> +       printf("T0:  " REG_FMT " T1:  " REG_FMT " T2:  " REG_FMT "\n",
> +              regs->t0, regs->t1, regs->t2);
> +       printf("S0:  " REG_FMT " S1:  " REG_FMT " A0:  " REG_FMT "\n",
> +              regs->s0, regs->s1, regs->a0);
> +       printf("A1:  " REG_FMT " A2:  " REG_FMT " A3:  " REG_FMT "\n",
> +              regs->a1, regs->a2, regs->a3);
> +       printf("A4:  " REG_FMT " A5:  " REG_FMT " A6:  " REG_FMT "\n",
> +              regs->a4, regs->a5, regs->a6);
> +       printf("A7:  " REG_FMT " S2:  " REG_FMT " S3:  " REG_FMT "\n",
> +              regs->a7, regs->s2, regs->s3);
> +       printf("S4:  " REG_FMT " S5:  " REG_FMT " S6:  " REG_FMT "\n",
> +              regs->s4, regs->s5, regs->s6);
> +       printf("S7:  " REG_FMT " S8:  " REG_FMT " S9:  " REG_FMT "\n",
> +              regs->s7, regs->s8, regs->s9);
> +       printf("S10: " REG_FMT " S11: " REG_FMT " T3:  " REG_FMT "\n",
> +              regs->s10, regs->s11, regs->t3);
> +       printf("T4:  " REG_FMT " T5:  " REG_FMT " T6:  " REG_FMT "\n\n",
> +              regs->t4, regs->t5, regs->t6);
>  #endif
>  }
>
> @@ -69,8 +76,14 @@ static void _exit_trap(ulong code, ulong epc, ulong tval, struct pt_regs *regs)
>         else
>                 printf("Unhandled exception code: %ld\n", code);
>
> -       printf("EPC: " REG_FMT " TVAL: " REG_FMT "\n", epc, tval);
> +       printf("EPC: " REG_FMT " RA: " REG_FMT " TVAL: " REG_FMT "\n",
> +              epc, regs->ra, tval);
> +       if (gd->flags & GD_FLG_RELOC)
> +               printf("EPC: " REG_FMT " RA: " REG_FMT " reloc adjusted\n\n",
> +                      epc - gd->reloc_off, regs->ra - gd->reloc_off);
> +
>         show_regs(regs);
> +       show_efi_loaded_images(epc);
>         hang();
>  }
>
> --

Reviewed-by: Rick Chen <rick at andestech.com>