Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-30 14:52:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

powerpc fixes for 5.1 #6

Browse Source 
A one-liner to make our Radix MMU support depend on HUGETLB_PAGE. We use some of
 the hugetlb inlines (eg. pud_huge()) when operating on the linear mapping and if
 they're compiled into empty wrappers we can corrupt memory.
 
 Then two fixes to our VFIO IOMMU code. The first is not a regression but fixes
 the locking to avoid a user-triggerable deadlock.
 
 The second does fix a regression since rc1, and depends on the first fix. It
 makes it possible to run guests with large amounts of memory again (~256GB).
 
 Thanks to:
   Alexey Kardashevskiy.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJcxUumAAoJEFHr6jzI4aWAEXwP/0x1hscWlJdpblLKc0Mh7kud
 MYUiEjxTsw2r8QeEJ5e3AtDh44DyuhrnL09w01vpsKMzVVC5vZDOQVXuAexeI8vO
 iv3pfpUhNyvNjpVDH1rHGJuQ4hJHIKr34GoNAhAfgW7yiZEvFOir2qd+bQm7KKgQ
 H2xvRiEXUJ3p1nVzOt2XYXEInTB2VWkwEfeNXLmh0AIySlAK1OLlrvZaZ4LzI7Bn
 Binbn+mIeftFWbXMOG8jhbiaTf6v9KQeWj5fTmaGEfBP3FBHjMQNf7krgCkq5Juh
 Ijxc20ardxBXeOq8E23q8+oAuGfpZjsKO3PPtl0r/Eyub65+FMP98//7iXvmwChL
 bkRwC+05LLMZPHYJ9UcWBKreEy1BDzb7nPWzvGkSyXnOVylavw+xZk22imAj/5pk
 auuuizTpTrW8c9WDYoWDkBVfbOOo44o4Eor51pYbC8Tq6cOkIYA6uO80JAD9yz6L
 FuKwrapMYKo779LAiX6u46iB6AVAaq/2TktwwnyZSqmj/oIiwNMKhrlENiO+CwgH
 PvDkrs0HA02F9nyHUreIQr5DQDgrgw4ZnMsatxvzBu/zBoe2RITfRms4c8WmKb+w
 y63ezFx4+FiFQGkniEY5/+o7ewpUFw6JyjKI+Q02tFKUKnq+iZQHtMxgJgxswxN/
 k8EUzlyS2ZY8d7vHHQ4u
 =oJ9o
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "A one-liner to make our Radix MMU support depend on HUGETLB_PAGE. We
  use some of the hugetlb inlines (eg. pud_huge()) when operating on the
  linear mapping and if they're compiled into empty wrappers we can
  corrupt memory.

  Then two fixes to our VFIO IOMMU code. The first is not a regression
  but fixes the locking to avoid a user-triggerable deadlock.

  The second does fix a regression since rc1, and depends on the first
  fix. It makes it possible to run guests with large amounts of memory
  again (~256GB).

  Thanks to Alexey Kardashevskiy"

* tag 'powerpc-5.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm_iommu: Allow pinning large regions
  powerpc/mm_iommu: Fix potential deadlock
  powerpc/mm/radix: Make Radix require HUGETLB_PAGE
This commit is contained in:
Linus Torvalds 2019-04-28 10:43:15 -07:00
commit 0d82044e1b
3 changed files with 61 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/powerpc/configs/skiroot_defconfig
View File

@ -266,6 +266,7 @@ CONFIG_UDF_FS=m
CONFIG_MSDOS_FS=m
CONFIG_VFAT_FS=m
CONFIG_PROC_KCORE=y
CONFIG_HUGETLBFS=y
# CONFIG_MISC_FILESYSTEMS is not set
# CONFIG_NETWORK_FILESYSTEMS is not set
CONFIG_NLS=y

99
arch/powerpc/mm/mmu_context_iommu.c
View File

@ -95,28 +95,15 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
unsigned long entries, unsigned long dev_hpa,
struct mm_iommu_table_group_mem_t **pmem)
{
struct mm_iommu_table_group_mem_t *mem;
long i, ret, locked_entries = 0;
struct mm_iommu_table_group_mem_t *mem, *mem2;
long i, ret, locked_entries = 0, pinned = 0;
unsigned int pageshift;
mutex_lock(&mem_list_mutex);
list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,
next) {
/* Overlap? */
if ((mem->ua < (ua + (entries << PAGE_SHIFT))) &&
(ua < (mem->ua +
(mem->entries << PAGE_SHIFT)))) {
ret = -EINVAL;
goto unlock_exit;
}
}
unsigned long entry, chunk;
if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) {
ret = mm_iommu_adjust_locked_vm(mm, entries, true);
if (ret)
goto unlock_exit;
return ret;
locked_entries = entries;
}
@ -148,17 +135,27 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
}
down_read(&mm->mmap_sem);
ret = get_user_pages_longterm(ua, entries, FOLL_WRITE, mem->hpages, NULL);
up_read(&mm->mmap_sem);
if (ret != entries) {
/* free the reference taken */
for (i = 0; i < ret; i++)
put_page(mem->hpages[i]);
chunk = (1UL << (PAGE_SHIFT + MAX_ORDER - 1)) /
sizeof(struct vm_area_struct *);
chunk = min(chunk, entries);
for (entry = 0; entry < entries; entry += chunk) {
unsigned long n = min(entries - entry, chunk);
vfree(mem->hpas);
kfree(mem);
ret = -EFAULT;
goto unlock_exit;
ret = get_user_pages_longterm(ua + (entry << PAGE_SHIFT), n,
FOLL_WRITE, mem->hpages + entry, NULL);
if (ret == n) {
pinned += n;
continue;
}
if (ret > 0)
pinned += ret;
break;
}
up_read(&mm->mmap_sem);
if (pinned != entries) {
if (!ret)
ret = -EFAULT;
goto free_exit;
}
pageshift = PAGE_SHIFT;
@ -183,21 +180,43 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
}
good_exit:
ret = 0;
atomic64_set(&mem->mapped, 1);
mem->used = 1;
mem->ua = ua;
mem->entries = entries;
*pmem = mem;
mutex_lock(&mem_list_mutex);
list_for_each_entry_rcu(mem2, &mm->context.iommu_group_mem_list, next) {
/* Overlap? */
if ((mem2->ua < (ua + (entries << PAGE_SHIFT))) &&
(ua < (mem2->ua +
(mem2->entries << PAGE_SHIFT)))) {
ret = -EINVAL;
mutex_unlock(&mem_list_mutex);
goto free_exit;
}
}
list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);
unlock_exit:
if (locked_entries && ret)
mm_iommu_adjust_locked_vm(mm, locked_entries, false);
mutex_unlock(&mem_list_mutex);
*pmem = mem;
return 0;
free_exit:
/* free the reference taken */
for (i = 0; i < pinned; i++)
put_page(mem->hpages[i]);
vfree(mem->hpas);
kfree(mem);
unlock_exit:
mm_iommu_adjust_locked_vm(mm, locked_entries, false);
return ret;
}
@ -266,7 +285,7 @@ static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem)
long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
{
long ret = 0;
unsigned long entries, dev_hpa;
unsigned long unlock_entries = 0;
mutex_lock(&mem_list_mutex);
@ -287,17 +306,17 @@ long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
goto unlock_exit;
}
/* @mapped became 0 so now mappings are disabled, release the region */
entries = mem->entries;
dev_hpa = mem->dev_hpa;
mm_iommu_release(mem);
if (mem->dev_hpa == MM_IOMMU_TABLE_INVALID_HPA)
unlock_entries = mem->entries;
if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA)
mm_iommu_adjust_locked_vm(mm, entries, false);
/* @mapped became 0 so now mappings are disabled, release the region */
mm_iommu_release(mem);
unlock_exit:
mutex_unlock(&mem_list_mutex);
mm_iommu_adjust_locked_vm(mm, unlock_entries, false);
return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_put);

2
arch/powerpc/platforms/Kconfig.cputype
View File

@ -324,7 +324,7 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
config PPC_RADIX_MMU
bool "Radix MMU Support"
depends on PPC_BOOK3S_64
depends on PPC_BOOK3S_64 && HUGETLB_PAGE
select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
default y
help