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>
diff --git a/arch/arm/lib/interrupts_64.c b/arch/arm/lib/interrupts_64.c
index 0bfdb8d..a32a4b6 100644
--- a/arch/arm/lib/interrupts_64.c
+++ b/arch/arm/lib/interrupts_64.c
@@ -30,6 +30,17 @@
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 @@
printf("x%-2d: %016lx x%-2d: %016lx\n",
i, regs->regs[i], i+1, regs->regs[i+1]);
printf("\n");
+ dump_instr(regs);
}
/*