On Thu, Nov 24, 2016 at 06:58:05PM +0900, AKASHI Takahiro wrote:
> diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> index 04744dc..b5168e8 100644
> --- a/arch/arm64/include/asm/kexec.h
> +++ b/arch/arm64/include/asm/kexec.h
> @@ -40,7 +40,47 @@
> static inline void crash_setup_regs(struct pt_regs *newregs,
> struct pt_regs *oldregs)
> {
> - /* Empty routine needed to avoid build errors. */
> + if (oldregs) {
> + memcpy(newregs, oldregs, sizeof(*newregs));
> + } else {
> + u64 tmp1, tmp2;
> +
> + __asm__ __volatile__ (
> + "stp x0, x1, [%2, #16 * 0]\n"
> + "stp x2, x3, [%2, #16 * 1]\n"
> + "stp x4, x5, [%2, #16 * 2]\n"
> + "stp x6, x7, [%2, #16 * 3]\n"
> + "stp x8, x9, [%2, #16 * 4]\n"
> + "stp x10, x11, [%2, #16 * 5]\n"
> + "stp x12, x13, [%2, #16 * 6]\n"
> + "stp x14, x15, [%2, #16 * 7]\n"
> + "stp x16, x17, [%2, #16 * 8]\n"
> + "stp x18, x19, [%2, #16 * 9]\n"
> + "stp x20, x21, [%2, #16 * 10]\n"
> + "stp x22, x23, [%2, #16 * 11]\n"
> + "stp x24, x25, [%2, #16 * 12]\n"
> + "stp x26, x27, [%2, #16 * 13]\n"
> + "stp x28, x29, [%2, #16 * 14]\n"
> + "mov %0, sp\n"
> + "stp x30, %0, [%2, #16 * 15]\n"
> +
> + "/* faked current PSTATE */\n"
> + "mrs %0, CurrentEL\n"
> + "mrs %1, SPSEL\n"
> + "orr %0, %0, %1\n"
> + "mrs %1, DAIF\n"
> + "orr %0, %0, %1\n"
> + "mrs %1, NZCV\n"
> + "orr %0, %0, %1\n"
> + /* pc */
> + "adr %1, 1f\n"
> + "1:\n"
> + "stp %1, %0, [%2, #16 * 16]\n"
> + : "+r" (tmp1), "+r" (tmp2)
> + : "r" (newregs)
> + : "memory"
tmp1 and tmp2 are not input arguments here, so you should use the "=&"
modifier. With my compiler, I get warnings of these variables being used
uninitialised.
--
Catalin
