From 75a1ba5b2c529db60ca49626bcaf0bddf4548438 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 3 Feb 2014 21:41:44 +0100 Subject: [PATCH] x86, microcode, AMD: Unify valid container checks 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: [] 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 Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1391460104-7261-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/microcode/amd_early.c | 43 +++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/amd_early.c b/arch/x86/kernel/cpu/microcode/amd_early.c index 8384c0f..617a9e2 100644 --- a/arch/x86/kernel/cpu/microcode/amd_early.c +++ b/arch/x86/kernel/cpu/microcode/amd_early.c @@ -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 (!uci->cpu_sig.sig) - smp_call_function_single(bsp, collect_cpu_sig_on_bsp, NULL, 1); + if (!container) + return -EINVAL; +#ifdef CONFIG_X86_32 + get_bsp_sig(); + cont = (unsigned long)container; +#else /* - * 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. + * We need the physical address of the container for both bitness since + * boot_params.hdr.ramdisk_image is a physical address. */ - container = (u8 *)(__va((u32)relocated_ramdisk) + - ((u32)container - boot_params.hdr.ramdisk_image)); + 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. + */ + 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); -- 2.7.4