[GIT PULL] x86 fixes

Ingo Molnar
2017-06-02T06:54:24Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: c08d517480ea342cc43acdacc5cf4a795e18151d Revert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"

Misc fixes:

- revert a broken PAT commit that broke a number of systems,

- fix two preemptability warnings/bugs that can trigger under certain
circumstances, in the debug code and in the microcode loader.

Thanks,

Ingo

------------------>
Borislav Petkov (2):
x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug
x86/debug/32: Convert a smp_processor_id() call to raw to avoid DEBUG_PREEMPT warning

Ingo Molnar (1):
Revert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"

arch/x86/kernel/cpu/microcode/amd.c | 16 ++++++++--------
arch/x86/kernel/process_32.c | 2 +-
arch/x86/mm/pat.c | 9 +++------
3 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 45db4d2ebd01..e9f4d762aa5b 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -320,7 +320,7 @@ void load_ucode_amd_ap(unsigned int cpuid_1_eax)
}

static enum ucode_state
-load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size);
+load_microcode_amd(bool save, u8 family, const u8 *data, size_t size);

int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax)
{
@@ -338,8 +338,7 @@ int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax)
if (!desc.mc)
return -EINVAL;

- ret = load_microcode_amd(smp_processor_id(), x86_family(cpuid_1_eax),
- desc.data, desc.size);
+ ret = load_microcode_amd(true, x86_family(cpuid_1_eax), desc.data, desc.size);
if (ret != UCODE_OK)
return -EINVAL;

@@ -675,7 +674,7 @@ static enum ucode_state __load_microcode_amd(u8 family, const u8 *data,
}

static enum ucode_state
-load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size)
+load_microcode_amd(bool save, u8 family, const u8 *data, size_t size)
{
enum ucode_state ret;

@@ -689,8 +688,8 @@ load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size)

#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),
@@ -722,11 +721,12 @@ 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)
@@ -743,7 +743,7 @@ 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);
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index ff40e74c9181..ffeae818aa7a 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -78,7 +78,7 @@ void __show_regs(struct pt_regs *regs, int all)

printk(KERN_DEFAULT "EIP: %pS\n", (void *)regs->ip);
printk(KERN_DEFAULT "EFLAGS: %08lx CPU: %d\n", regs->flags,
- smp_processor_id());
+ raw_smp_processor_id());

printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
regs->ax, regs->bx, regs->cx, regs->dx);
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 83a59a67757a..9b78685b66e6 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -65,11 +65,9 @@ static int __init nopat(char *str)
}
early_param("nopat", nopat);

-static bool __read_mostly __pat_initialized = false;
-
bool pat_enabled(void)
{
- return __pat_initialized;
+ return !!__pat_enabled;
}
EXPORT_SYMBOL_GPL(pat_enabled);

@@ -227,14 +225,13 @@ static void pat_bsp_init(u64 pat)
}

wrmsrl(MSR_IA32_CR_PAT, pat);
- __pat_initialized = true;

__init_cache_modes(pat);
}

static void pat_ap_init(u64 pat)
{
- if (!this_cpu_has(X86_FEATURE_PAT)) {
+ if (!boot_cpu_has(X86_FEATURE_PAT)) {
/*
* If this happens we are on a secondary CPU, but switched to
* PAT on the boot CPU. We have no way to undo PAT.
@@ -309,7 +306,7 @@ void pat_init(void)
u64 pat;
struct cpuinfo_x86 *c = &boot_cpu_data;

- if (!__pat_enabled) {
+ if (!pat_enabled()) {
init_cache_modes();
return;
}