arm64: print instructions leading to exception

If an exception occurs in a loaded image and the relocation offset is
unknown, it is helpful to know the instructions pointed to by the
program counter. This patch adds the missing output.

A possible output is:
    Code: 910c4021 aa1303e0 f9400662 d63f0040 (e7f7defb)

The parentheses indicate the instruction causing the exception.

The output can be disassembled using scripts/decodecode:

echo 'Code: 90000360 9100b800 94002782 17ffff8f (e7f7defb)' | \
  ARCH=arm64 scripts/decodecode

Code: 90000360 9100b800 94002782 17ffff8f (e7f7defb)
All code
========
   0:   90000360    adrp    x0, 0x6c000
   4:   9100b800    add     x0, x0, #0x2e
   8:   94002782    bl      0x9e10
   c:   17ffff8f    b       0xfffffffffffffe48
  10:*  e7f7defb    .inst   0xe7f7defb ; undefined <-- trapping instruction

Code starting with the faulting instruction
===========================================
   0:   e7f7defb    .inst   0xe7f7defb ; undefined

We already have implemented the same for armv7.

For testing command 'exception undefined' can be used.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Heinrich Schuchardt 2019-09-12 19:09:26 +02:00 committed by Tom Rini
parent 100e75bbdb
commit 57bbf44de6

View file

@ -30,6 +30,17 @@ static void show_efi_loaded_images(struct pt_regs *regs)
efi_print_image_infos((void *)regs->elr);
}
static void dump_instr(struct pt_regs *regs)
{
u32 *addr = (u32 *)(regs->elr & ~3UL);
int i;
printf("Code: ");
for (i = -4; i < 1; i++)
printf(i == 0 ? "(%08x) " : "%08x ", addr[i]);
printf("\n");
}
void show_regs(struct pt_regs *regs)
{
int i;
@ -44,6 +55,7 @@ void show_regs(struct pt_regs *regs)
printf("x%-2d: %016lx x%-2d: %016lx\n",
i, regs->regs[i], i+1, regs->regs[i+1]);
printf("\n");
dump_instr(regs);
}
/*