diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 06978b4dbeb8..d16b33bacc32 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -323,7 +323,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ -#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */ #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */ @@ -1833,7 +1833,12 @@ static inline unsigned long memdesc_section(memdesc_flags_t mdf) { return (mdf.f >> SECTIONS_PGSHIFT) & SECTIONS_MASK; } -#endif +#else /* !SECTION_IN_PAGE_FLAGS */ +static inline unsigned long memdesc_section(memdesc_flags_t mdf) +{ + return 0; +} +#endif /* SECTION_IN_PAGE_FLAGS */ /** * folio_pfn - Return the Page Frame Number of a folio. @@ -4258,14 +4263,13 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); * since this value becomes part of PP_SIGNATURE; meaning we can just use the * space between the PP_SIGNATURE value (without POISON_POINTER_DELTA), and the * lowest bits of POISON_POINTER_DELTA. On arches where POISON_POINTER_DELTA is - * 0, we make sure that we leave the two topmost bits empty, as that guarantees - * we won't mistake a valid kernel pointer for a value we set, regardless of the - * VMSPLIT setting. + * 0, we use the lowest bit of PAGE_OFFSET as the boundary if that value is + * known at compile-time. * - * Altogether, this means that the number of bits available is constrained by - * the size of an unsigned long (at the upper end, subtracting two bits per the - * above), and the definition of PP_SIGNATURE (with or without - * POISON_POINTER_DELTA). + * If the value of PAGE_OFFSET is not known at compile time, or if it is too + * small to leave at least 8 bits available above PP_SIGNATURE, we define the + * number of bits to be 0, which turns off the DMA index tracking altogether + * (see page_pool_register_dma_index()). */ #define PP_DMA_INDEX_SHIFT (1 + __fls(PP_SIGNATURE - POISON_POINTER_DELTA)) #if POISON_POINTER_DELTA > 0 @@ -4274,8 +4278,13 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); */ #define PP_DMA_INDEX_BITS MIN(32, __ffs(POISON_POINTER_DELTA) - PP_DMA_INDEX_SHIFT) #else -/* Always leave out the topmost two; see above. */ -#define PP_DMA_INDEX_BITS MIN(32, BITS_PER_LONG - PP_DMA_INDEX_SHIFT - 2) +/* Use the lowest bit of PAGE_OFFSET if there's at least 8 bits available; see above */ +#define PP_DMA_INDEX_MIN_OFFSET (1 << (PP_DMA_INDEX_SHIFT + 8)) +#define PP_DMA_INDEX_BITS ((__builtin_constant_p(PAGE_OFFSET) && \ + PAGE_OFFSET >= PP_DMA_INDEX_MIN_OFFSET && \ + !(PAGE_OFFSET & (PP_DMA_INDEX_MIN_OFFSET - 1))) ? \ + MIN(32, __ffs(PAGE_OFFSET) - PP_DMA_INDEX_SHIFT) : 0) + #endif #define PP_DMA_INDEX_MASK GENMASK(PP_DMA_INDEX_BITS + PP_DMA_INDEX_SHIFT - 1, \ |