[GIT PULL] x86/mm changes for v4.5

From: Ingo Molnar
Date: Mon Jan 11 2016 - 10:05:52 EST

Linus,

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

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

# HEAD: 1f1a89ac05f6e88aa341e86e57435fdbb1177c0c x86/mm: Micro-optimise clflush_cache_range()

The main changes in this cycle were:

- make the debugfs 'kernel_page_tables' file read-only, as it only has read ops.
(Borislav Petkov)

- micro-optimize clflush_cache_range() (Chris Wilson)

- swiotlb enhancements, which fixes certain KVM emulated devices (Igor Mammedov)

- fix an LDT related debug message (Jan Beulich)

- modularize CONFIG_X86_PTDUMP (Kees Cook)

- tone down an overly alarming warning (Laura Abbott)

- Mark variable __initdata (Rasmus Villemoes)

- PAT additions (Toshi Kani)

out-of-topic modifications in x86-mm-for-linus:
-------------------------------------------------
include/asm-generic/pgtable.h # d9fe4fab1197: x86/mm/pat: Add untrack_pfn_
include/linux/bootmem.h # 8dd330300197: x86/mm: Introduce max_possib
mm/bootmem.c # 8dd330300197: x86/mm: Introduce max_possib
mm/mremap.c # d9fe4fab1197: x86/mm/pat: Add untrack_pfn_
mm/nobootmem.c # 8dd330300197: x86/mm: Introduce max_possib

Thanks,

Ingo

------------------>
Borislav Petkov (1):
x86/mm/ptdump: Make (debugfs)/kernel_page_tables read-only

Chris Wilson (1):
x86/mm: Micro-optimise clflush_cache_range()

Igor Mammedov (2):
x86/mm: Introduce max_possible_pfn
x86/mm/64: Enable SWIOTLB if system has SRAT memory regions above MAX_DMA32_PFN

Jan Beulich (1):
x86/LDT: Print the real LDT base address

Kees Cook (1):
x86/mm: Turn CONFIG_X86_PTDUMP into a module

Laura Abbott (1):
x86/mm: Drop WARN from multi-BAR check

Rasmus Villemoes (1):
x86/mm/mtrr: Mark the 'range_new' static variable in mtrr_calc_range_state() as __initdata

Toshi Kani (2):
x86/mm/pat: Add untrack_pfn_moved for mremap
x86/mm/pat: Change free_memtype() to support shrinking case


arch/x86/Kconfig.debug | 2 +-
arch/x86/kernel/cpu/mtrr/cleanup.c | 11 ++++++--
arch/x86/kernel/pci-swiotlb.c | 2 +-
arch/x86/kernel/process_64.c | 2 +-
arch/x86/kernel/setup.c | 2 ++
arch/x86/mm/Makefile | 1 +
arch/x86/mm/debug_pagetables.c | 46 +++++++++++++++++++++++++++++++++
arch/x86/mm/dump_pagetables.c | 34 ++-----------------------
arch/x86/mm/ioremap.c | 4 +--
arch/x86/mm/pageattr.c | 10 +++++---
arch/x86/mm/pat.c | 12 ++++++++-
arch/x86/mm/pat_rbtree.c | 52 +++++++++++++++++++++++++++++++-------
arch/x86/mm/srat.c | 2 ++
include/asm-generic/pgtable.h | 10 +++++++-
include/linux/bootmem.h | 4 +++
mm/bootmem.c | 1 +
mm/mremap.c | 4 +++
mm/nobootmem.c | 1 +
18 files changed, 146 insertions(+), 54 deletions(-)
create mode 100644 arch/x86/mm/debug_pagetables.c

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 137dfa96aa14..110253ce83af 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -69,7 +69,7 @@ config X86_PTDUMP_CORE
def_bool n

config X86_PTDUMP
- bool "Export kernel pagetable layout to userspace via debugfs"
+ tristate "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL
select DEBUG_FS
select X86_PTDUMP_CORE
diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c
index 70d7c93f4550..0d98503c2245 100644
--- a/arch/x86/kernel/cpu/mtrr/cleanup.c
+++ b/arch/x86/kernel/cpu/mtrr/cleanup.c
@@ -593,9 +593,16 @@ mtrr_calc_range_state(u64 chunk_size, u64 gran_size,
unsigned long x_remove_base,
unsigned long x_remove_size, int i)
{
- static struct range range_new[RANGE_NUM];
+ /*
+ * range_new should really be an automatic variable, but
+ * putting 4096 bytes on the stack is frowned upon, to put it
+ * mildly. It is safe to make it a static __initdata variable,
+ * since mtrr_calc_range_state is only called during init and
+ * there's no way it will call itself recursively.
+ */
+ static struct range range_new[RANGE_NUM] __initdata;
unsigned long range_sums_new;
- static int nr_range_new;
+ int nr_range_new;
int num_reg;

/* Convert ranges to var ranges state: */
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index adf0392d549a..7c577a178859 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -88,7 +88,7 @@ int __init pci_swiotlb_detect_4gb(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
#ifdef CONFIG_X86_64
- if (!no_iommu && max_pfn > MAX_DMA32_PFN)
+ if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
return swiotlb;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e835d263a33b..b9d99e0f82c4 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -125,7 +125,7 @@ void release_thread(struct task_struct *dead_task)
if (dead_task->mm->context.ldt) {
pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
dead_task->comm,
- dead_task->mm->context.ldt,
+ dead_task->mm->context.ldt->entries,
dead_task->mm->context.ldt->size);
BUG();
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 29db25f9a745..16a846548ece 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1048,6 +1048,8 @@ void __init setup_arch(char **cmdline_p)
if (mtrr_trim_uncached_memory(max_pfn))
max_pfn = e820_end_of_ram_pfn();

+ max_possible_pfn = max_pfn;
+
#ifdef CONFIG_X86_32
/* max_low_pfn get updated here */
find_low_pfn_range();
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 65c47fda26fc..f9d38a48e3c8 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o

obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_X86_PTDUMP_CORE) += dump_pagetables.o
+obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o

obj-$(CONFIG_HIGHMEM) += highmem_32.o

diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
new file mode 100644
index 000000000000..bfcffdf6c577
--- /dev/null
+++ b/arch/x86/mm/debug_pagetables.c
@@ -0,0 +1,46 @@
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <asm/pgtable.h>
+
+static int ptdump_show(struct seq_file *m, void *v)
+{
+ ptdump_walk_pgd_level(m, NULL);
+ return 0;
+}
+
+static int ptdump_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, ptdump_show, NULL);
+}
+
+static const struct file_operations ptdump_fops = {
+ .owner = THIS_MODULE,
+ .open = ptdump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *pe;
+
+static int __init pt_dump_debug_init(void)
+{
+ pe = debugfs_create_file("kernel_page_tables", S_IRUSR, NULL, NULL,
+ &ptdump_fops);
+ if (!pe)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __exit pt_dump_debug_exit(void)
+{
+ debugfs_remove_recursive(pe);
+}
+
+module_init(pt_dump_debug_init);
+module_exit(pt_dump_debug_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index a035c2aa7801..90a1dc054873 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -426,38 +426,15 @@ void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd)
{
ptdump_walk_pgd_level_core(m, pgd, false);
}
+EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level);

void ptdump_walk_pgd_level_checkwx(void)
{
ptdump_walk_pgd_level_core(NULL, NULL, true);
}

-#ifdef CONFIG_X86_PTDUMP
-static int ptdump_show(struct seq_file *m, void *v)
+static int __init pt_dump_init(void)
{
- ptdump_walk_pgd_level(m, NULL);
- return 0;
-}
-
-static int ptdump_open(struct inode *inode, struct file *filp)
-{
- return single_open(filp, ptdump_show, NULL);
-}
-
-static const struct file_operations ptdump_fops = {
- .open = ptdump_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-#endif
-
-static int pt_dump_init(void)
-{
-#ifdef CONFIG_X86_PTDUMP
- struct dentry *pe;
-#endif
-
#ifdef CONFIG_X86_32
/* Not a compile-time constant on x86-32 */
address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
@@ -468,13 +445,6 @@ static int pt_dump_init(void)
address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
#endif

-#ifdef CONFIG_X86_PTDUMP
- pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
- &ptdump_fops);
- if (!pe)
- return -ENOMEM;
-#endif
-
return 0;
}

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index b9c78f3bcd67..0d8d53d1f5cc 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -194,8 +194,8 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
* Check if the request spans more than any BAR in the iomem resource
* tree.
*/
- WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr, unaligned_size),
- KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
+ if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size))
+ pr_warn("caller %pS mapping multiple BARs\n", caller);

return ret_addr;
err_free_area:
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a3137a4feed1..6000ad7f560c 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -129,14 +129,16 @@ within(unsigned long addr, unsigned long start, unsigned long end)
*/
void clflush_cache_range(void *vaddr, unsigned int size)
{
- unsigned long clflush_mask = boot_cpu_data.x86_clflush_size - 1;
+ const unsigned long clflush_size = boot_cpu_data.x86_clflush_size;
+ void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1));
void *vend = vaddr + size;
- void *p;
+
+ if (p >= vend)
+ return;

mb();

- for (p = (void *)((unsigned long)vaddr & ~clflush_mask);
- p < vend; p += boot_cpu_data.x86_clflush_size)
+ for (; p < vend; p += clflush_size)
clflushopt(p);

mb();
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 188e3e07eeeb..031782e74231 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -586,7 +586,7 @@ int free_memtype(u64 start, u64 end)
entry = rbt_memtype_erase(start, end);
spin_unlock(&memtype_lock);

- if (!entry) {
+ if (IS_ERR(entry)) {
pr_info("x86/PAT: %s:%d freeing invalid memtype [mem %#010Lx-%#010Lx]\n",
current->comm, current->pid, start, end - 1);
return -EINVAL;
@@ -992,6 +992,16 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
vma->vm_flags &= ~VM_PAT;
}

+/*
+ * untrack_pfn_moved is called, while mremapping a pfnmap for a new region,
+ * with the old vma after its pfnmap page table has been removed. The new
+ * vma has a new pfnmap to the same pfn & cache type with VM_PAT set.
+ */
+void untrack_pfn_moved(struct vm_area_struct *vma)
+{
+ vma->vm_flags &= ~VM_PAT;
+}
+
pgprot_t pgprot_writecombine(pgprot_t prot)
{
return __pgprot(pgprot_val(prot) |
diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index 63931080366a..2f7702253ccf 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -98,8 +98,13 @@ static struct memtype *memtype_rb_lowest_match(struct rb_root *root,
return last_lower; /* Returns NULL if there is no overlap */
}

-static struct memtype *memtype_rb_exact_match(struct rb_root *root,
- u64 start, u64 end)
+enum {
+ MEMTYPE_EXACT_MATCH = 0,
+ MEMTYPE_END_MATCH = 1
+};
+
+static struct memtype *memtype_rb_match(struct rb_root *root,
+ u64 start, u64 end, int match_type)
{
struct memtype *match;

@@ -107,7 +112,12 @@ static struct memtype *memtype_rb_exact_match(struct rb_root *root,
while (match != NULL && match->start < end) {
struct rb_node *node;

- if (match->start == start && match->end == end)
+ if ((match_type == MEMTYPE_EXACT_MATCH) &&
+ (match->start == start) && (match->end == end))
+ return match;
+
+ if ((match_type == MEMTYPE_END_MATCH) &&
+ (match->start < start) && (match->end == end))
return match;

node = rb_next(&match->rb);
@@ -117,7 +127,7 @@ static struct memtype *memtype_rb_exact_match(struct rb_root *root,
match = NULL;
}

- return NULL; /* Returns NULL if there is no exact match */
+ return NULL; /* Returns NULL if there is no match */
}

static int memtype_rb_check_conflict(struct rb_root *root,
@@ -210,12 +220,36 @@ struct memtype *rbt_memtype_erase(u64 start, u64 end)
{
struct memtype *data;

- data = memtype_rb_exact_match(&memtype_rbroot, start, end);
- if (!data)
- goto out;
+ /*
+ * Since the memtype_rbroot tree allows overlapping ranges,
+ * rbt_memtype_erase() checks with EXACT_MATCH first, i.e. free
+ * a whole node for the munmap case. If no such entry is found,
+ * it then checks with END_MATCH, i.e. shrink the size of a node
+ * from the end for the mremap case.
+ */
+ data = memtype_rb_match(&memtype_rbroot, start, end,
+ MEMTYPE_EXACT_MATCH);
+ if (!data) {
+ data = memtype_rb_match(&memtype_rbroot, start, end,
+ MEMTYPE_END_MATCH);
+ if (!data)
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (data->start == start) {
+ /* munmap: erase this node */
+ rb_erase_augmented(&data->rb, &memtype_rbroot,
+ &memtype_rb_augment_cb);
+ } else {
+ /* mremap: update the end value of this node */
+ rb_erase_augmented(&data->rb, &memtype_rbroot,
+ &memtype_rb_augment_cb);
+ data->end = start;
+ data->subtree_max_end = data->end;
+ memtype_rb_insert(&memtype_rbroot, data);
+ return NULL;
+ }

- rb_erase_augmented(&data->rb, &memtype_rbroot, &memtype_rb_augment_cb);
-out:
return data;
}

diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index c2aea63bee20..b5f821881465 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -203,6 +203,8 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
(unsigned long long)start, (unsigned long long)end - 1);

+ max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
+
return 0;
out_err_bad_srat:
bad_srat();
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 14b0ff32fb9f..3a6803cb0ec9 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -569,7 +569,7 @@ static inline int track_pfn_copy(struct vm_area_struct *vma)
}

/*
- * untrack_pfn_vma is called while unmapping a pfnmap for a region.
+ * untrack_pfn is called while unmapping a pfnmap for a region.
* untrack can be called for a specific region indicated by pfn and size or
* can be for the entire vma (in which case pfn, size are zero).
*/
@@ -577,6 +577,13 @@ static inline void untrack_pfn(struct vm_area_struct *vma,
unsigned long pfn, unsigned long size)
{
}
+
+/*
+ * untrack_pfn_moved is called while mremapping a pfnmap for a new region.
+ */
+static inline void untrack_pfn_moved(struct vm_area_struct *vma)
+{
+}
#else
extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr,
@@ -586,6 +593,7 @@ extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
extern int track_pfn_copy(struct vm_area_struct *vma);
extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
unsigned long size);
+extern void untrack_pfn_moved(struct vm_area_struct *vma);
#endif

#ifdef __HAVE_COLOR_ZERO_PAGE
diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index f589222bfa87..35b22f94d2d2 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -19,6 +19,10 @@ extern unsigned long min_low_pfn;
* highest page
*/
extern unsigned long max_pfn;
+/*
+ * highest possible page
+ */
+extern unsigned long long max_possible_pfn;

#ifndef CONFIG_NO_BOOTMEM
/*
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 3b6380784c28..91e32bc8517f 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -33,6 +33,7 @@ EXPORT_SYMBOL(contig_page_data);
unsigned long max_low_pfn;
unsigned long min_low_pfn;
unsigned long max_pfn;
+unsigned long long max_possible_pfn;

bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;

diff --git a/mm/mremap.c b/mm/mremap.c
index c25bc6268e46..de824e72c3e8 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -319,6 +319,10 @@ static unsigned long move_vma(struct vm_area_struct *vma,
hiwater_vm = mm->hiwater_vm;
vm_stat_account(mm, vma->vm_flags, vma->vm_file, new_len>>PAGE_SHIFT);

+ /* Tell pfnmap has moved from this vma */
+ if (unlikely(vma->vm_flags & VM_PFNMAP))
+ untrack_pfn_moved(vma);
+
if (do_munmap(mm, old_addr, old_len) < 0) {
/* OOM: unable to split vma, just get accounts right */
vm_unacct_memory(excess >> PAGE_SHIFT);
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index e57cf24babd6..99feb2b07fc5 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -31,6 +31,7 @@ EXPORT_SYMBOL(contig_page_data);
unsigned long max_low_pfn;
unsigned long min_low_pfn;
unsigned long max_pfn;
+unsigned long long max_possible_pfn;

static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
u64 goal, u64 limit)