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The virtual_address_range selftest reads from the start of each mapping listed in /proc/self/maps. However not all mappings are valid to be arbitrarily accessed. For example the vvar data used for virtual clocks on x86 [vvar_vclock] can only be accessed if 1) the kernel configuration enables virtual clocks and 2) the hypervisor provided the data for it. Only the VDSO itself has the necessary information to know this. Since commite93d2521b2("x86/vdso: Split virtual clock pages into dedicated mapping") the virtual clock data was split out into its own mapping, leading to EFAULT from read() during the validation. Check for the VM_IO flag as a proxy. It is present for the VVAR mappings and MMIO ranges can be dangerous to access arbitrarily. Link: https://lkml.kernel.org/r/20250114-virtual_address_range-tests-v4-4-6fd7269934a5@linutronix.de Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202412271148.2656e485-lkp@intel.com Fixes:e93d2521b2("x86/vdso: Split virtual clock pages into dedicated mapping") Fixes:0104096498("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Suggested-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/lkml/e97c2a5d-c815-4936-a767-ac42a3220a90@redhat.com/ Acked-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
66 lines
2.2 KiB
C
66 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#include <stdint.h>
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#include <stdbool.h>
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#include <sys/mman.h>
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#include <err.h>
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#include <strings.h> /* ffsl() */
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#include <unistd.h> /* _SC_PAGESIZE */
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#define BIT_ULL(nr) (1ULL << (nr))
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#define PM_SOFT_DIRTY BIT_ULL(55)
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#define PM_MMAP_EXCLUSIVE BIT_ULL(56)
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#define PM_UFFD_WP BIT_ULL(57)
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#define PM_FILE BIT_ULL(61)
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#define PM_SWAP BIT_ULL(62)
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#define PM_PRESENT BIT_ULL(63)
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extern unsigned int __page_size;
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extern unsigned int __page_shift;
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static inline unsigned int psize(void)
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{
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if (!__page_size)
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__page_size = sysconf(_SC_PAGESIZE);
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return __page_size;
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}
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static inline unsigned int pshift(void)
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{
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if (!__page_shift)
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__page_shift = (ffsl(psize()) - 1);
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return __page_shift;
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}
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uint64_t pagemap_get_entry(int fd, char *start);
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bool pagemap_is_softdirty(int fd, char *start);
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bool pagemap_is_swapped(int fd, char *start);
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bool pagemap_is_populated(int fd, char *start);
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unsigned long pagemap_get_pfn(int fd, char *start);
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void clear_softdirty(void);
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bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len);
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uint64_t read_pmd_pagesize(void);
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unsigned long rss_anon(void);
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bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
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bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
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bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
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int64_t allocate_transhuge(void *ptr, int pagemap_fd);
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unsigned long default_huge_page_size(void);
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int detect_hugetlb_page_sizes(size_t sizes[], int max);
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int uffd_register(int uffd, void *addr, uint64_t len,
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bool miss, bool wp, bool minor);
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int uffd_unregister(int uffd, void *addr, uint64_t len);
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int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len,
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bool miss, bool wp, bool minor, uint64_t *ioctls);
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unsigned long get_free_hugepages(void);
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bool check_vmflag_io(void *addr);
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/*
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* On ppc64 this will only work with radix 2M hugepage size
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*/
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#define HPAGE_SHIFT 21
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#define HPAGE_SIZE (1 << HPAGE_SHIFT)
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#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
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#define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1))
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