[PATCH v2 1/4] hugetlbfs: add arch_hugetlb_valid_size

From: Mike Kravetz
Date: Wed Apr 01 2020 - 14:40:17 EST

The architecture independent routine hugetlb_default_setup sets up
the default huge pages size. It has no way to verify if the passed
value is valid, so it accepts it and attempts to validate at a later
time. This requires undocumented cooperation between the arch specific
and arch independent code.

For architectures that support more than one huge page size, provide
a routine arch_hugetlb_valid_size to validate a huge page size.
hugetlb_default_setup can use this to validate passed values.

arch_hugetlb_valid_size will also be used in a subsequent patch to
move processing of the "hugepagesz=" in arch specific code to a common
routine in arch independent code.

Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
arch/arm64/include/asm/hugetlb.h | 2 ++
arch/arm64/mm/hugetlbpage.c | 17 +++++++++++++----
arch/powerpc/include/asm/hugetlb.h | 3 +++
arch/powerpc/mm/hugetlbpage.c | 20 +++++++++++++-------
arch/riscv/include/asm/hugetlb.h | 3 +++
arch/riscv/mm/hugetlbpage.c | 26 +++++++++++++++++---------
arch/s390/include/asm/hugetlb.h | 3 +++
arch/s390/mm/hugetlbpage.c | 16 ++++++++++++----
arch/sparc/include/asm/hugetlb.h | 3 +++
arch/sparc/mm/init_64.c | 24 ++++++++++++++++--------
arch/x86/include/asm/hugetlb.h | 5 +++++
arch/x86/mm/hugetlbpage.c | 17 +++++++++++++----
include/linux/hugetlb.h | 7 +++++++
mm/hugetlb.c | 15 ++++++++++++---
14 files changed, 122 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 2eb6c234d594..81606223494f 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -59,6 +59,8 @@ extern void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
extern void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte, unsigned long sz);
#define set_huge_swap_pte_at set_huge_swap_pte_at
+bool __init arch_hugetlb_valid_size(unsigned long size);
+#define arch_hugetlb_valid_size arch_hugetlb_valid_size

#include <asm-generic/hugetlb.h>

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index bbeb6a5a6ba6..069b96ee2aec 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -462,17 +462,26 @@ static int __init hugetlbpage_init(void)
}
arch_initcall(hugetlbpage_init);

-static __init int setup_hugepagesz(char *opt)
+bool __init arch_hugetlb_valid_size(unsigned long size)
{
- unsigned long ps = memparse(opt, &opt);
-
- switch (ps) {
+ switch (size) {
#ifdef CONFIG_ARM64_4K_PAGES
case PUD_SIZE:
#endif
case CONT_PMD_SIZE:
case PMD_SIZE:
case CONT_PTE_SIZE:
+ return true;
+ }
+
+ return false;
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+ unsigned long ps = memparse(opt, &opt);
+
+ if (arch_hugetlb_valid_size(ps)) {
add_huge_page_size(ps);
return 1;
}
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index bd6504c28c2f..19b453ee1431 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -64,6 +64,9 @@ static inline void arch_clear_hugepage_flags(struct page *page)
{
}

+#define arch_hugetlb_valid_size arch_hugetlb_valid_size
+bool __init arch_hugetlb_valid_size(unsigned long size);
+
#include <asm-generic/hugetlb.h>

#else /* ! CONFIG_HUGETLB_PAGE */
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 33b3461d91e8..de54d2a37830 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -558,7 +558,7 @@ unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
return vma_kernel_pagesize(vma);
}

-static int __init add_huge_page_size(unsigned long long size)
+bool __init arch_hugetlb_valid_size(unsigned long size)
{
int shift = __ffs(size);
int mmu_psize;
@@ -566,20 +566,26 @@ static int __init add_huge_page_size(unsigned long long size)
/* Check that it is a page size supported by the hardware and
* that it fits within pagetable and slice limits. */
if (size <= PAGE_SIZE || !is_power_of_2(size))
- return -EINVAL;
+ return false;

mmu_psize = check_and_get_huge_psize(shift);
if (mmu_psize < 0)
- return -EINVAL;
+ return false;

BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);

- /* Return if huge page size has already been setup */
- if (size_to_hstate(size))
- return 0;
+ return true;
+}

- hugetlb_add_hstate(shift - PAGE_SHIFT);
+static int __init add_huge_page_size(unsigned long long size)
+{
+ int shift = __ffs(size);
+
+ if (!arch_hugetlb_valid_size((unsigned long)size))
+ return -EINVAL;

+ if (!size_to_hstate(size))
+ hugetlb_add_hstate(shift - PAGE_SHIFT);
return 0;
}

diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index 728a5db66597..a6c414fa5b82 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -5,6 +5,9 @@
#include <asm-generic/hugetlb.h>
#include <asm/page.h>

+bool __init arch_hugetlb_valid_size(unsigned long size);
+#define arch_hugetlb_valid_size arch_hugetlb_valid_size
+
static inline int is_hugepage_only_range(struct mm_struct *mm,
unsigned long addr,
unsigned long len) {
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index a6189ed36c5f..da1f516bc451 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -12,21 +12,29 @@ int pmd_huge(pmd_t pmd)
return pmd_leaf(pmd);
}

+bool __init arch_hugetlb_valid_size(unsigned long size)
+{
+ if (size == HPAGE_SIZE)
+ return true;
+ else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
+ return true;
+ else
+ return false;
+}
+
static __init int setup_hugepagesz(char *opt)
{
unsigned long ps = memparse(opt, &opt);

- if (ps == HPAGE_SIZE) {
- hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
- } else if (IS_ENABLED(CONFIG_64BIT) && ps == PUD_SIZE) {
- hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
- } else {
- hugetlb_bad_size();
- pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
- return 0;
+ if (arch_hugetlb_valid_size(ps)) {
+ hugetlb_add_hstate(ilog2(ps) - PAGE_SHIFT);
+ return 1;
}

- return 1;
+ hugetlb_bad_size();
+ pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
+ return 0;
+
}
__setup("hugepagesz=", setup_hugepagesz);

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index de8f0bf5f238..f49981c00e72 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -15,6 +15,9 @@
#define hugetlb_free_pgd_range free_pgd_range
#define hugepages_supported() (MACHINE_HAS_EDAT1)

+bool __init arch_hugetlb_valid_size(unsigned long size);
+#define arch_hugetlb_valid_size arch_hugetlb_valid_size
+
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);
pte_t huge_ptep_get(pte_t *ptep);
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index f01daddcbc5e..ac25b207624c 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -251,16 +251,24 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address,
return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
}

+bool __init arch_hugetlb_valid_size(unsigned long size)
+{
+ if (MACHINE_HAS_EDAT1 && size == PMD_SIZE)
+ return true;
+ else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE)
+ return true;
+ else
+ return false;
+}
+
static __init int setup_hugepagesz(char *opt)
{
unsigned long size;
char *string = opt;

size = memparse(opt, &opt);
- if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
- hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
- } else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
- hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ if (arch_hugetlb_valid_size(size)) {
+ hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT);
} else {
hugetlb_bad_size();
pr_err("hugepagesz= specifies an unsupported page size %s\n",
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index 3963f80d1cb3..a88668b455d3 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -10,6 +10,9 @@ struct pud_huge_patch_entry {
unsigned int insn;
};
extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end;
+
+bool __init arch_hugetlb_valid_size(unsigned long size);
+#define arch_hugetlb_valid_size arch_hugetlb_valid_size
#endif

#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 1cf0d666dea3..2bfe8e22b706 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -360,16 +360,11 @@ static void __init pud_huge_patch(void)
__asm__ __volatile__("flush %0" : : "r" (addr));
}

-static int __init setup_hugepagesz(char *string)
+bool __init arch_hugetlb_valid_size(unsigned long size)
{
- unsigned long long hugepage_size;
- unsigned int hugepage_shift;
+ unsigned int hugepage_shift = ilog2(size);
unsigned short hv_pgsz_idx;
unsigned int hv_pgsz_mask;
- int rc = 0;
-
- hugepage_size = memparse(string, &string);
- hugepage_shift = ilog2(hugepage_size);

switch (hugepage_shift) {
case HPAGE_16GB_SHIFT:
@@ -397,7 +392,20 @@ static int __init setup_hugepagesz(char *string)
hv_pgsz_mask = 0;
}

- if ((hv_pgsz_mask & cpu_pgsz_mask) == 0U) {
+ if ((hv_pgsz_mask & cpu_pgsz_mask) == 0U)
+ return false;
+
+ return true;
+}
+
+static int __init setup_hugepagesz(char *string)
+{
+ unsigned long long hugepage_size;
+ int rc = 0;
+
+ hugepage_size = memparse(string, &string);
+
+ if (!arch_hugetlb_valid_size((unsigned long)hugepage_size)) {
hugetlb_bad_size();
pr_err("hugepagesz=%llu not supported by MMU.\n",
hugepage_size);
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index f65cfb48cfdd..53ae4df41433 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -7,6 +7,11 @@

#define hugepages_supported() boot_cpu_has(X86_FEATURE_PSE)

+#ifdef CONFIG_X86_64
+bool __init arch_hugetlb_valid_size(unsigned long size);
+#define arch_hugetlb_valid_size arch_hugetlb_valid_size
+#endif
+
static inline int is_hugepage_only_range(struct mm_struct *mm,
unsigned long addr,
unsigned long len) {
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 5bfd5aef5378..1c4372bfe782 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -181,13 +181,22 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
#endif /* CONFIG_HUGETLB_PAGE */

#ifdef CONFIG_X86_64
+bool __init arch_hugetlb_valid_size(unsigned long size)
+{
+ if (size == PMD_SIZE)
+ return true;
+ else if (size == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES))
+ return true;
+ else
+ return false;
+}
+
static __init int setup_hugepagesz(char *opt)
{
unsigned long ps = memparse(opt, &opt);
- if (ps == PMD_SIZE) {
- hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
- } else if (ps == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES)) {
- hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+
+ if (arch_hugetlb_valid_size(ps)) {
+ hugetlb_add_hstate(ilog2(ps) - PAGE_SHIFT);
} else {
hugetlb_bad_size();
printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n",
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 2fc9bc91894e..962bb1e6682b 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -688,6 +688,13 @@ static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
return &mm->page_table_lock;
}

+#ifndef arch_hugetlb_valid_size
+static inline bool arch_hugetlb_valid_size(unsigned long size)
+{
+ return size == HPAGE_SIZE;
+}
+#endif
+
#ifndef hugepages_supported
/*
* Some platform decide whether they support huge pages at boot
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 38c3363b46e1..e9d9d179cf12 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3324,12 +3324,21 @@ static int __init hugetlb_nrpages_setup(char *s)
}
__setup("hugepages=", hugetlb_nrpages_setup);

-static int __init hugetlb_default_setup(char *s)
+static int __init default_hugepagesz_setup(char *s)
{
- default_hstate_size = memparse(s, &s);
+ unsigned long size;
+
+ size = (unsigned long)memparse(s, NULL);
+
+ if (!arch_hugetlb_valid_size(size)) {
+ pr_err("HugeTLB: unsupported default_hugepagesz %s\n", s);
+ return 0;
+ }
+
+ default_hstate_size = size;
return 1;
}
-__setup("default_hugepagesz=", hugetlb_default_setup);
+__setup("default_hugepagesz=", default_hugepagesz_setup);

static unsigned int cpuset_mems_nr(unsigned int *array)
{
--
2.25.1