[GIT PULL] x86 and PTI fixes

From: Ingo Molnar
Date: Sun Mar 25 2018 - 05:17:55 EST


Linus,

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

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

# HEAD: d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9 x86/entry/64: Don't use IST entry for #BP stack

Misc fixes:

- fix EFI pagetables freeing
- fix vsyscall pagetable setting on Xen PV guests
- remove ancient CONFIG_X86_PPRO_FENCE=y - x86 is TSO again
- fix two binutils (ld) development version related incompatibilities
- clean up breakpoint handling
- fix an x86 self-test

Thanks,

Ingo

------------------>
Andy Lutomirski (2):
selftests/x86/ptrace_syscall: Fix for yet more glibc interference
x86/entry/64: Don't use IST entry for #BP stack

Boris Ostrovsky (1):
x86/vsyscall/64: Use proper accessor to update P4D entry

Christoph Hellwig (1):
x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk

H.J. Lu (2):
x86/build/64: Force the linker to use 2MB page size
x86/boot/64: Verify alignment of the LOAD segment

Waiman Long (1):
x86/efi: Free efi_pgd with free_pages()


arch/x86/Kconfig.cpu | 13 ------------
arch/x86/Makefile | 9 +++++++++
arch/x86/boot/compressed/misc.c | 4 ++++
arch/x86/entry/entry_64.S | 2 +-
arch/x86/entry/vdso/vdso32/vclock_gettime.c | 2 --
arch/x86/entry/vsyscall/vsyscall_64.c | 2 +-
arch/x86/include/asm/barrier.h | 30 ----------------------------
arch/x86/include/asm/io.h | 15 --------------
arch/x86/kernel/idt.c | 2 --
arch/x86/kernel/pci-nommu.c | 19 ------------------
arch/x86/kernel/traps.c | 15 +++++++-------
arch/x86/platform/efi/efi_64.c | 2 +-
arch/x86/um/asm/barrier.h | 4 ----
tools/testing/selftests/x86/ptrace_syscall.c | 8 ++++++--
14 files changed, 30 insertions(+), 97 deletions(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 65a9a4716e34..f0c5ef578153 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -315,19 +315,6 @@ config X86_L1_CACHE_SHIFT
default "4" if MELAN || M486 || MGEODEGX1
default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX

-config X86_PPRO_FENCE
- bool "PentiumPro memory ordering errata workaround"
- depends on M686 || M586MMX || M586TSC || M586 || M486 || MGEODEGX1
- ---help---
- Old PentiumPro multiprocessor systems had errata that could cause
- memory operations to violate the x86 ordering standard in rare cases.
- Enabling this option will attempt to work around some (but not all)
- occurrences of this problem, at the cost of much heavier spinlock and
- memory barrier operations.
-
- If unsure, say n here. Even distro kernels should think twice before
- enabling this: there are few systems, and an unlikely bug.
-
config X86_F00F_BUG
def_bool y
depends on M586MMX || M586TSC || M586 || M486
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 498c1b812300..1c4d012550ec 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -223,6 +223,15 @@ KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr)

LDFLAGS := -m elf_$(UTS_MACHINE)

+#
+# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to
+# the linker to force 2MB page size regardless of the default page size used
+# by the linker.
+#
+ifdef CONFIG_X86_64
+LDFLAGS += $(call ld-option, -z max-page-size=0x200000)
+endif
+
# Speed up the build
KBUILD_CFLAGS += -pipe
# Workaround for a gcc prelease that unfortunately was shipped in a suse release
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 98761a1576ce..252fee320816 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -309,6 +309,10 @@ static void parse_elf(void *output)

switch (phdr->p_type) {
case PT_LOAD:
+#ifdef CONFIG_X86_64
+ if ((phdr->p_align % 0x200000) != 0)
+ error("Alignment of LOAD segment isn't multiple of 2MB");
+#endif
#ifdef CONFIG_RELOCATABLE
dest = output;
dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index d5c7f18f79ac..9b114675fbc0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1138,7 +1138,7 @@ apicinterrupt3 HYPERV_REENLIGHTENMENT_VECTOR \
#endif /* CONFIG_HYPERV */

idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
-idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0
idtentry stack_segment do_stack_segment has_error_code=1

#ifdef CONFIG_XEN
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
index 7780bbfb06ef..9242b28418d5 100644
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -5,8 +5,6 @@
#undef CONFIG_OPTIMIZE_INLINING
#endif

-#undef CONFIG_X86_PPRO_FENCE
-
#ifdef CONFIG_X86_64

/*
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 8560ef68a9d6..317be365bce3 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -347,7 +347,7 @@ void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
p4d = p4d_offset(pgd, VSYSCALL_ADDR);
#if CONFIG_PGTABLE_LEVELS >= 5
- p4d->p4d |= _PAGE_USER;
+ set_p4d(p4d, __p4d(p4d_val(*p4d) | _PAGE_USER));
#endif
pud = pud_offset(p4d, VSYSCALL_ADDR);
set_pud(pud, __pud(pud_val(*pud) | _PAGE_USER));
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index e1259f043ae9..042b5e892ed1 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -52,11 +52,7 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \
"lfence", X86_FEATURE_LFENCE_RDTSC)

-#ifdef CONFIG_X86_PPRO_FENCE
-#define dma_rmb() rmb()
-#else
#define dma_rmb() barrier()
-#endif
#define dma_wmb() barrier()

#ifdef CONFIG_X86_32
@@ -68,30 +64,6 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
#define __smp_wmb() barrier()
#define __smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)

-#if defined(CONFIG_X86_PPRO_FENCE)
-
-/*
- * For this option x86 doesn't have a strong TSO memory
- * model and we should fall back to full barriers.
- */
-
-#define __smp_store_release(p, v) \
-do { \
- compiletime_assert_atomic_type(*p); \
- __smp_mb(); \
- WRITE_ONCE(*p, v); \
-} while (0)
-
-#define __smp_load_acquire(p) \
-({ \
- typeof(*p) ___p1 = READ_ONCE(*p); \
- compiletime_assert_atomic_type(*p); \
- __smp_mb(); \
- ___p1; \
-})
-
-#else /* regular x86 TSO memory ordering */
-
#define __smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
@@ -107,8 +79,6 @@ do { \
___p1; \
})

-#endif
-
/* Atomic operations are already serializing on x86 */
#define __smp_mb__before_atomic() barrier()
#define __smp_mb__after_atomic() barrier()
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 95e948627fd0..f6e5b9375d8c 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -232,21 +232,6 @@ extern void set_iounmap_nonlazy(void);
*/
#define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))

-/*
- * Cache management
- *
- * This needed for two cases
- * 1. Out of order aware processors
- * 2. Accidentally out of order processors (PPro errata #51)
- */
-
-static inline void flush_write_buffers(void)
-{
-#if defined(CONFIG_X86_PPRO_FENCE)
- asm volatile("lock; addl $0,0(%%esp)": : :"memory");
-#endif
-}
-
#endif /* __KERNEL__ */

extern void native_io_delay(void);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 56d99be3706a..50bee5fe1140 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -160,7 +160,6 @@ static const __initconst struct idt_data early_pf_idts[] = {
*/
static const __initconst struct idt_data dbg_idts[] = {
INTG(X86_TRAP_DB, debug),
- INTG(X86_TRAP_BP, int3),
};
#endif

@@ -183,7 +182,6 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
static const __initconst struct idt_data ist_idts[] = {
ISTG(X86_TRAP_DB, debug, DEBUG_STACK),
ISTG(X86_TRAP_NMI, nmi, NMI_STACK),
- SISTG(X86_TRAP_BP, int3, DEBUG_STACK),
ISTG(X86_TRAP_DF, double_fault, DOUBLEFAULT_STACK),
#ifdef CONFIG_X86_MCE
ISTG(X86_TRAP_MC, &machine_check, MCE_STACK),
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 618285e475c6..ac7ea3a8242f 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -37,7 +37,6 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
WARN_ON(size == 0);
if (!check_addr("map_single", dev, bus, size))
return NOMMU_MAPPING_ERROR;
- flush_write_buffers();
return bus;
}

@@ -72,25 +71,9 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
return 0;
s->dma_length = s->length;
}
- flush_write_buffers();
return nents;
}

-static void nommu_sync_single_for_device(struct device *dev,
- dma_addr_t addr, size_t size,
- enum dma_data_direction dir)
-{
- flush_write_buffers();
-}
-
-
-static void nommu_sync_sg_for_device(struct device *dev,
- struct scatterlist *sg, int nelems,
- enum dma_data_direction dir)
-{
- flush_write_buffers();
-}
-
static int nommu_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
return dma_addr == NOMMU_MAPPING_ERROR;
@@ -101,8 +84,6 @@ const struct dma_map_ops nommu_dma_ops = {
.free = dma_generic_free_coherent,
.map_sg = nommu_map_sg,
.map_page = nommu_map_page,
- .sync_single_for_device = nommu_sync_single_for_device,
- .sync_sg_for_device = nommu_sync_sg_for_device,
.is_phys = 1,
.mapping_error = nommu_mapping_error,
.dma_supported = x86_dma_supported,
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 3d9b2308e7fa..03f3d7695dac 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -577,7 +577,6 @@ do_general_protection(struct pt_regs *regs, long error_code)
}
NOKPROBE_SYMBOL(do_general_protection);

-/* May run on IST stack. */
dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
{
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -592,6 +591,13 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
if (poke_int3_handler(regs))
return;

+ /*
+ * Use ist_enter despite the fact that we don't use an IST stack.
+ * We can be called from a kprobe in non-CONTEXT_KERNEL kernel
+ * mode or even during context tracking state changes.
+ *
+ * This means that we can't schedule. That's okay.
+ */
ist_enter(regs);
RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
@@ -609,15 +615,10 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
SIGTRAP) == NOTIFY_STOP)
goto exit;

- /*
- * Let others (NMI) know that the debug stack is in use
- * as we may switch to the interrupt stack.
- */
- debug_stack_usage_inc();
cond_local_irq_enable(regs);
do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
cond_local_irq_disable(regs);
- debug_stack_usage_dec();
+
exit:
ist_exit(regs);
}
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index c310a8284358..f9cfbc0d1f33 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -227,7 +227,7 @@ int __init efi_alloc_page_tables(void)
if (!pud) {
if (CONFIG_PGTABLE_LEVELS > 4)
free_page((unsigned long) pgd_page_vaddr(*pgd));
- free_page((unsigned long)efi_pgd);
+ free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
return -ENOMEM;
}

diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h
index b7d73400ea29..f31e5d903161 100644
--- a/arch/x86/um/asm/barrier.h
+++ b/arch/x86/um/asm/barrier.h
@@ -30,11 +30,7 @@

#endif /* CONFIG_X86_32 */

-#ifdef CONFIG_X86_PPRO_FENCE
-#define dma_rmb() rmb()
-#else /* CONFIG_X86_PPRO_FENCE */
#define dma_rmb() barrier()
-#endif /* CONFIG_X86_PPRO_FENCE */
#define dma_wmb() barrier()

#include <asm-generic/barrier.h>
diff --git a/tools/testing/selftests/x86/ptrace_syscall.c b/tools/testing/selftests/x86/ptrace_syscall.c
index 1ae1c5a7392e..6f22238f3217 100644
--- a/tools/testing/selftests/x86/ptrace_syscall.c
+++ b/tools/testing/selftests/x86/ptrace_syscall.c
@@ -183,8 +183,10 @@ static void test_ptrace_syscall_restart(void)
if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
err(1, "PTRACE_TRACEME");

+ pid_t pid = getpid(), tid = syscall(SYS_gettid);
+
printf("\tChild will make one syscall\n");
- raise(SIGSTOP);
+ syscall(SYS_tgkill, pid, tid, SIGSTOP);

syscall(SYS_gettid, 10, 11, 12, 13, 14, 15);
_exit(0);
@@ -301,9 +303,11 @@ static void test_restart_under_ptrace(void)
if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
err(1, "PTRACE_TRACEME");

+ pid_t pid = getpid(), tid = syscall(SYS_gettid);
+
printf("\tChild will take a nap until signaled\n");
setsigign(SIGUSR1, SA_RESTART);
- raise(SIGSTOP);
+ syscall(SYS_tgkill, pid, tid, SIGSTOP);

syscall(SYS_pause, 0, 0, 0, 0, 0, 0);
_exit(0);