[PATCH v12 07/11] x86/kasan: add and use kasan_map_populate()
STALE3257d
From: Pavel Tatashin <hidden>
Date: 2017-10-13 17:33:45
Also in:
linux-mm, linuxppc-dev, lkml, sparclinux
Subsystem:
kasan, the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Andrey Ryabinin, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
Revision v12 of 6 in this series.
Revisions (6)
During early boot, kasan uses vmemmap_populate() to establish its shadow memory. But, that interface is intended for struct pages use. Because of the current project, vmemmap won't be zeroed during allocation, but kasan expects that memory to be zeroed. We are adding a new kasan_map_populate() function to resolve this difference. Therefore, we must use a new interface to allocate and map kasan shadow memory, that also zeroes memory for us. Signed-off-by: Pavel Tatashin <redacted> --- arch/x86/mm/kasan_init_64.c | 75 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 71 insertions(+), 4 deletions(-)
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index bc84b73684b7..9778fec8a5dc 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c@@ -15,6 +15,73 @@ extern struct range pfn_mapped[E820_MAX_ENTRIES]; +/* Creates mappings for kasan during early boot. The mapped memory is zeroed */ +static int __meminit kasan_map_populate(unsigned long start, unsigned long end, + int node) +{ + unsigned long addr, pfn, next; + unsigned long long size; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + int ret; + + ret = vmemmap_populate(start, end, node); + /* + * We might have partially populated memory, so check for no entries, + * and zero only those that actually exist. + */ + for (addr = start; addr < end; addr = next) { + pgd = pgd_offset_k(addr); + if (pgd_none(*pgd)) { + next = pgd_addr_end(addr, end); + continue; + } + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) { + next = p4d_addr_end(addr, end); + continue; + } + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) { + next = pud_addr_end(addr, end); + continue; + } + if (pud_large(*pud)) { + /* This is PUD size page */ + next = pud_addr_end(addr, end); + size = PUD_SIZE; + pfn = pud_pfn(*pud); + } else { + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) { + next = pmd_addr_end(addr, end); + continue; + } + if (pmd_large(*pmd)) { + /* This is PMD size page */ + next = pmd_addr_end(addr, end); + size = PMD_SIZE; + pfn = pmd_pfn(*pmd); + } else { + pte = pte_offset_kernel(pmd, addr); + next = addr + PAGE_SIZE; + if (pte_none(*pte)) + continue; + /* This is base size page */ + size = PAGE_SIZE; + pfn = pte_pfn(*pte); + } + } + memset(phys_to_virt(PFN_PHYS(pfn)), 0, size); + } + return ret; +} + static int __init map_range(struct range *range) { unsigned long start;
@@ -23,7 +90,7 @@ static int __init map_range(struct range *range) start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start)); end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end)); - return vmemmap_populate(start, end, NUMA_NO_NODE); + return kasan_map_populate(start, end, NUMA_NO_NODE); } static void __init clear_pgds(unsigned long start,
@@ -136,9 +203,9 @@ void __init kasan_init(void) kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), kasan_mem_to_shadow((void *)__START_KERNEL_map)); - vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext), - (unsigned long)kasan_mem_to_shadow(_end), - NUMA_NO_NODE); + kasan_map_populate((unsigned long)kasan_mem_to_shadow(_stext), + (unsigned long)kasan_mem_to_shadow(_end), + NUMA_NO_NODE); kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END), (void *)KASAN_SHADOW_END);
--
2.14.2