diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-microcode-AMD-Change-load_microcode_amd-s-param-.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-microcode-AMD-Change-load_microcode_amd-s-param-.patch | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-microcode-AMD-Change-load_microcode_amd-s-param-.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-microcode-AMD-Change-load_microcode_amd-s-param-.patch new file mode 100644 index 00000000..00297c34 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0011-x86-microcode-AMD-Change-load_microcode_amd-s-param-.patch @@ -0,0 +1,133 @@ +From df2f7e0d21ca37bdbdf3fc5b6fa42a9b0bc6fbd6 Mon Sep 17 00:00:00 2001 +From: Borislav Petkov <bp@suse.de> +Date: Mon, 19 Feb 2018 11:13:28 +0100 +Subject: [PATCH 11/12] x86/microcode/AMD: Change load_microcode_amd()'s param + to bool to fix preemptibility bug + +commit dac6ca243c4c49a9ca7507d3d66140ebfac8b04b upstream. + +With CONFIG_DEBUG_PREEMPT enabled, I get: + + BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 + caller is debug_smp_processor_id + CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2+ #2 + Call Trace: + dump_stack + check_preemption_disabled + debug_smp_processor_id + save_microcode_in_initrd_amd + ? microcode_init + save_microcode_in_initrd + ... + +because, well, it says it above, we're using smp_processor_id() in +preemptible code. + +But passing the CPU number is not really needed. It is only used to +determine whether we're on the BSP, and, if so, to save the microcode +patch for early loading. + + [ We don't absolutely need to do it on the BSP but we do that + customarily there. ] + +Instead, convert that function parameter to a boolean which denotes +whether the patch should be saved or not, thereby avoiding the use of +smp_processor_id() in preemptible code. + +Signed-off-by: Borislav Petkov <bp@suse.de> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Thomas Gleixner <tglx@linutronix.de> +Link: http://lkml.kernel.org/r/20170528200414.31305-1-bp@alien8.de +Signed-off-by: Ingo Molnar <mingo@kernel.org> +[arnd: rebased to 4.9, after running into warning: + arch/x86/kernel/cpu/microcode/amd.c:881:30: self-comparison always evaluates to true] +Signed-off-by: Arnd Bergmann <arnd@arndb.de> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/include/asm/microcode_amd.h | 1 - + arch/x86/kernel/cpu/microcode/amd.c | 17 +++++++++++------ + 2 files changed, 11 insertions(+), 7 deletions(-) + +diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h +index 15eb754..98ccbd1 100644 +--- a/arch/x86/include/asm/microcode_amd.h ++++ b/arch/x86/include/asm/microcode_amd.h +@@ -59,7 +59,6 @@ static inline u16 find_equiv_id(struct equiv_cpu_entry *equiv_cpu_table, + + extern int __apply_microcode_amd(struct microcode_amd *mc_amd); + extern int apply_microcode_amd(int cpu); +-extern enum ucode_state load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size); + + #define PATCH_MAX_SIZE PAGE_SIZE + +diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c +index 017bda1..aaab28a 100644 +--- a/arch/x86/kernel/cpu/microcode/amd.c ++++ b/arch/x86/kernel/cpu/microcode/amd.c +@@ -135,6 +135,9 @@ static size_t compute_container_size(u8 *data, u32 total_size) + return size; + } + ++static enum ucode_state ++load_microcode_amd(bool save, u8 family, const u8 *data, size_t size); ++ + /* + * Early load occurs before we can vmalloc(). So we look for the microcode + * patch container file in initrd, traverse equivalent cpu table, look for a +@@ -451,7 +454,7 @@ int __init save_microcode_in_initrd_amd(void) + eax = cpuid_eax(0x00000001); + eax = ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff); + +- ret = load_microcode_amd(smp_processor_id(), eax, container, container_size); ++ ret = load_microcode_amd(true, eax, container, container_size); + if (ret != UCODE_OK) + retval = -EINVAL; + +@@ -860,7 +863,8 @@ static enum ucode_state __load_microcode_amd(u8 family, const u8 *data, + return UCODE_OK; + } + +-enum ucode_state load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size) ++static enum ucode_state ++load_microcode_amd(bool save, u8 family, const u8 *data, size_t size) + { + enum ucode_state ret; + +@@ -874,8 +878,8 @@ enum ucode_state load_microcode_amd(int cpu, u8 family, const u8 *data, size_t s + + #ifdef CONFIG_X86_32 + /* save BSP's matching patch for early load */ +- if (cpu_data(cpu).cpu_index == boot_cpu_data.cpu_index) { +- struct ucode_patch *p = find_patch(cpu); ++ if (save) { ++ struct ucode_patch *p = find_patch(0); + if (p) { + memset(amd_ucode_patch, 0, PATCH_MAX_SIZE); + memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data), +@@ -907,11 +911,12 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device, + { + char fw_name[36] = "amd-ucode/microcode_amd.bin"; + struct cpuinfo_x86 *c = &cpu_data(cpu); ++ bool bsp = c->cpu_index == boot_cpu_data.cpu_index; + enum ucode_state ret = UCODE_NFOUND; + const struct firmware *fw; + + /* reload ucode container only on the boot cpu */ +- if (!refresh_fw || c->cpu_index != boot_cpu_data.cpu_index) ++ if (!refresh_fw || !bsp) + return UCODE_OK; + + if (c->x86 >= 0x15) +@@ -928,7 +933,7 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device, + goto fw_release; + } + +- ret = load_microcode_amd(cpu, c->x86, fw->data, fw->size); ++ ret = load_microcode_amd(bsp, c->x86, fw->data, fw->size); + + fw_release: + release_firmware(fw); +-- +2.7.4 + |