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SubjectRe: AMD microcode loading broken on 32 bit
On 01/28/2014 04:37 PM, Boris Ostrovsky wrote:
> On 01/28/2014 04:30 PM, Borislav Petkov wrote:
>> On Tue, Jan 28, 2014 at 04:05:20PM -0500, Boris Ostrovsky wrote:
>>> Yes. This was a bug in our build environment. It is fixed now but I
>>> put this bug back when I was testing your patch.
>> Right, that was the deal. Oh well, we'd need to verify the container
>> too, I guess:

The patch seems to have fixed the problem.

-boris

>
> I'll give it a spin. Apparently the problem is currently in
> install_equiv_cpu_table()
> when we are trying to index into buf and buf (which is container)
> doesn't appear
> to be there.
>
> Are you sure that
>
> container = (u8 *)(__va((u32)relocated_ramdisk) +
> ((u32)container -
> boot_params.hdr.ramdisk_image));
>
> in save_microcode_in_initrd_amd() always results in a valid pointer?
> It is non-NULL but it
> points to address that looks to be not mapped.
>
> -boris
>
>>
>> ---
>> diff --git a/arch/x86/kernel/cpu/microcode/amd_early.c
>> b/arch/x86/kernel/cpu/microcode/amd_early.c
>> index 8384c0fa206f..c568b6c9af95 100644
>> --- a/arch/x86/kernel/cpu/microcode/amd_early.c
>> +++ b/arch/x86/kernel/cpu/microcode/amd_early.c
>> @@ -37,10 +37,12 @@ static __initdata char ucode_path[] =
>> "kernel/x86/microcode/AuthenticAMD.bin";
>> static struct cpio_data __init find_ucode_in_initrd(void)
>> {
>> + struct cpio_data ret;
>> long offset = 0;
>> char *path;
>> void *start;
>> size_t size;
>> + u32 *hdr;
>> #ifdef CONFIG_X86_32
>> struct boot_params *p;
>> @@ -59,7 +61,18 @@ static struct cpio_data __init
>> find_ucode_in_initrd(void)
>> size = boot_params.hdr.ramdisk_size;
>> #endif
>> - return find_cpio_data(path, start, size, &offset);
>> + ret = find_cpio_data(path, start, size, &offset);
>> +
>> + /* Verify we didn't get some garbage from the initrd. */
>> + hdr = (u32 *)ret.data;
>> +
>> + if (hdr[0] != UCODE_MAGIC ||
>> + hdr[1] != UCODE_EQUIV_CPU_TABLE_TYPE ||
>> + hdr[2] == 0) {
>> + ret.data = NULL;
>> + ret.size = 0;
>> + }
>> + return ret;
>> }
>> static size_t compute_container_size(u8 *data, u32 total_size)
>> @@ -359,7 +372,7 @@ int __init save_microcode_in_initrd_amd(void)
>> pr_info("microcode: updated early to new
>> patch_level=0x%08x\n",
>> ucode_new_rev);
>> - if (!container)
>> + if (!container || !ucode_cpio.data)
>> return -EINVAL;
>> eax = cpuid_eax(0x00000001);
>> --
>>
>



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