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x86, microcode, AMD: Unify valid container checks

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For additional coverage, BorisO and friends unknowlingly did swap AMD
microcode with Intel microcode blobs in order to see what happens. What
did happen on 32-bit was

[    5.722656] BUG: unable to handle kernel paging request at be3a6008
[    5.722693] IP: [<c106d6b4>] load_microcode_amd+0x24/0x3f0
[    5.722716] *pdpt = 0000000000000000 *pde = 0000000000000000

because there was a valid initrd there but without valid microcode in it
and the container check happened *after* the relocated ramdisk handling
on 32-bit, which was clearly wrong.

While at it, take care of the ramdisk relocation on both 32- and 64-bit
as it is done on both. Also, comment what we're doing because this code
is a bit tricky.

Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1391460104-7261-1-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Borislav Petkov 2014-02-03 21:41:44 +01:00 • committed by H. Peter Anvin
commit 75a1ba5b2c
1 changed files with 29 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

43
arch/x86/kernel/cpu/microcode/amd_early.c
View file

@ -285,6 +285,15 @@ static void __init collect_cpu_sig_on_bsp(void *arg)
uci->cpu_sig.sig = cpuid_eax(0x00000001);
}
static void __init get_bsp_sig(void)
{
unsigned int bsp = boot_cpu_data.cpu_index;
struct ucode_cpu_info *uci = ucode_cpu_info + bsp;
if (!uci->cpu_sig.sig)
smp_call_function_single(bsp, collect_cpu_sig_on_bsp, NULL, 1);
}
#else
void load_ucode_amd_ap(void)
{
@ -337,31 +346,37 @@ void load_ucode_amd_ap(void)
int __init save_microcode_in_initrd_amd(void)
{
unsigned long cont;
enum ucode_state ret;
u32 eax;
#ifdef CONFIG_X86_32
unsigned int bsp = boot_cpu_data.cpu_index;
struct ucode_cpu_info *uci = ucode_cpu_info + bsp;
if (!container)
return -EINVAL;
if (!uci->cpu_sig.sig)
smp_call_function_single(bsp, collect_cpu_sig_on_bsp, NULL, 1);
#ifdef CONFIG_X86_32
get_bsp_sig();
cont = (unsigned long)container;
#else
/*
* We need the physical address of the container for both bitness since
* boot_params.hdr.ramdisk_image is a physical address.
*/
cont = __pa(container);
#endif
/*
* Take into account the fact that the ramdisk might get relocated
* and therefore we need to recompute the container's position in
* virtual memory space.
* Take into account the fact that the ramdisk might get relocated and
* therefore we need to recompute the container's position in virtual
* memory space.
*/
container = (u8 *)(__va((u32)relocated_ramdisk) +
((u32)container - boot_params.hdr.ramdisk_image));
#endif
if (relocated_ramdisk)
container = (u8 *)(__va(relocated_ramdisk) +
(cont - boot_params.hdr.ramdisk_image));
if (ucode_new_rev)
pr_info("microcode: updated early to new patch_level=0x%08x\n",
ucode_new_rev);
if (!container)
return -EINVAL;
eax = cpuid_eax(0x00000001);
eax = ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff);