[GIT PULL] x86 fixes

Ingo Molnar
2019-02-10T09:13:48Z

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: 20e55bc17dd01f13cec0eb17e76e9511b23963ef x86/mm: Make set_pmd_at() paravirt aware

A handful of fixes:

- Fix an MCE corner case bug/crash found via MCE injection testing

- Fix 5-level paging boot crash

- Fix MCE recovery cache invalidation bug

- Fix regression on Xen guests caused by a recent PMD level mremap
speedup optimization

Thanks,

Ingo

------------------>
Juergen Gross (1):
x86/mm: Make set_pmd_at() paravirt aware

Kirill A. Shutemov (1):
x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting

Peter Zijlstra (1):
x86/mm/cpa: Fix set_mce_nospec()

Tony Luck (1):
x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()

arch/x86/boot/compressed/head_64.S | 2 ++
arch/x86/include/asm/pgtable.h | 2 +-
arch/x86/kernel/cpu/mce/core.c | 1 +
arch/x86/mm/pageattr.c | 50 +++++++++++++++++++-------------------
4 files changed, 29 insertions(+), 26 deletions(-)

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index f105ae8651c9..f62e347862cc 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -602,10 +602,12 @@ ENTRY(trampoline_32bit_src)
3:
/* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */
pushl %ecx
+ pushl %edx
movl $MSR_EFER, %ecx
rdmsr
btsl $_EFER_LME, %eax
wrmsr
+ popl %edx
popl %ecx

/* Enable PAE and LA57 (if required) paging modes */
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 40616e805292..2779ace16d23 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1065,7 +1065,7 @@ static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
- native_set_pmd(pmdp, pmd);
+ set_pmd(pmdp, pmd);
}

static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 672c7225cb1b..6ce290c506d9 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -784,6 +784,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
quirk_no_way_out(i, m, regs);

if (mce_severity(m, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
+ m->bank = i;
mce_read_aux(m, i);
*msg = tmp;
return 1;
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 4f8972311a77..14e6119838a6 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -230,6 +230,29 @@ static bool __cpa_pfn_in_highmap(unsigned long pfn)

#endif

+/*
+ * See set_mce_nospec().
+ *
+ * Machine check recovery code needs to change cache mode of poisoned pages to
+ * UC to avoid speculative access logging another error. But passing the
+ * address of the 1:1 mapping to set_memory_uc() is a fine way to encourage a
+ * speculative access. So we cheat and flip the top bit of the address. This
+ * works fine for the code that updates the page tables. But at the end of the
+ * process we need to flush the TLB and cache and the non-canonical address
+ * causes a #GP fault when used by the INVLPG and CLFLUSH instructions.
+ *
+ * But in the common case we already have a canonical address. This code
+ * will fix the top bit if needed and is a no-op otherwise.
+ */
+static inline unsigned long fix_addr(unsigned long addr)
+{
+#ifdef CONFIG_X86_64
+ return (long)(addr << 1) >> 1;
+#else
+ return addr;
+#endif
+}
+
static unsigned long __cpa_addr(struct cpa_data *cpa, unsigned long idx)
{
if (cpa->flags & CPA_PAGES_ARRAY) {
@@ -313,7 +336,7 @@ void __cpa_flush_tlb(void *data)
unsigned int i;

for (i = 0; i < cpa->numpages; i++)
- __flush_tlb_one_kernel(__cpa_addr(cpa, i));
+ __flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i)));
}

static void cpa_flush(struct cpa_data *data, int cache)
@@ -347,7 +370,7 @@ static void cpa_flush(struct cpa_data *data, int cache)
* Only flush present addresses:
*/
if (pte && (pte_val(*pte) & _PAGE_PRESENT))
- clflush_cache_range_opt((void *)addr, PAGE_SIZE);
+ clflush_cache_range_opt((void *)fix_addr(addr), PAGE_SIZE);
}
mb();
}
@@ -1627,29 +1650,6 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
return ret;
}

-/*
- * Machine check recovery code needs to change cache mode of poisoned
- * pages to UC to avoid speculative access logging another error. But
- * passing the address of the 1:1 mapping to set_memory_uc() is a fine
- * way to encourage a speculative access. So we cheat and flip the top
- * bit of the address. This works fine for the code that updates the
- * page tables. But at the end of the process we need to flush the cache
- * and the non-canonical address causes a #GP fault when used by the
- * CLFLUSH instruction.
- *
- * But in the common case we already have a canonical address. This code
- * will fix the top bit if needed and is a no-op otherwise.
- */
-static inline unsigned long make_addr_canonical_again(unsigned long addr)
-{
-#ifdef CONFIG_X86_64
- return (long)(addr << 1) >> 1;
-#else
- return addr;
-#endif
-}
-
-
static int change_page_attr_set_clr(unsigned long *addr, int numpages,
pgprot_t mask_set, pgprot_t mask_clr,
int force_split, int in_flag,