Created
August 4, 2023 21:51
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| #include <fcntl.h> | |
| #include <sys/ioctl.h> | |
| #include <linux/types.h> | |
| #include <string.h> | |
| #include <unistd.h> | |
| #include <stdlib.h> | |
| #include <stdio.h> | |
| /* Pagemap ioctl */ | |
| #define PAGEMAP_SCAN _IOWR('f', 16, struct pm_scan_arg) | |
| /* Bits are set in flags of the page_region and masks in pm_scan_args */ | |
| #define PAGE_IS_WRITTEN (1 << 0) | |
| #define PAGE_IS_FILE (1 << 1) | |
| #define PAGE_IS_PRESENT (1 << 2) | |
| #define PAGE_IS_SWAPPED (1 << 3) | |
| #define PAGE_IS_PFNZERO (1 << 4) | |
| /* | |
| * struct page_region - Page region with flags | |
| * @start: Start of the region | |
| * @len: Length of the region in pages | |
| * @bitmap: Bits sets for the region | |
| */ | |
| struct page_region { | |
| __u64 start; | |
| __u64 len; | |
| __u64 flags; | |
| }; | |
| /* | |
| * struct pm_scan_arg - Pagemap ioctl argument | |
| * @size: Size of the structure | |
| * @flags: Flags for the IOCTL | |
| * @start: Starting address of the region | |
| * (Ending address of the walk is also returned in it) | |
| * @end: Ending address of the region | |
| * @vec: Address of page_region struct array for output | |
| * @vec_len: Length of the page_region struct array | |
| * @max_pages: Optional max return pages | |
| * @required_mask: Required mask - All of these bits have to be set in the PTE | |
| * @anyof_mask: Any mask - Any of these bits are set in the PTE | |
| * @excluded_mask: Exclude mask - None of these bits are set in the PTE | |
| * @return_mask: Bits that are to be reported in page_region | |
| */ | |
| struct pm_scan_arg { | |
| __u64 size; | |
| __u64 flags; | |
| __u64 start; | |
| __u64 end; | |
| __u64 vec; | |
| __u64 vec_len; | |
| __u64 max_pages; | |
| __u64 required_mask; | |
| __u64 anyof_mask; | |
| __u64 excluded_mask; | |
| __u64 return_mask; | |
| }; | |
| /* Supported flags */ | |
| #define PM_SCAN_OP_GET (1 << 0) | |
| #define PM_SCAN_OP_WP (1 << 1) | |
| int main() | |
| { | |
| int fd = open("/proc/self/pagemap", O_RDONLY); | |
| if (fd < 0) | |
| return 1; | |
| struct page_region regs[1024]; | |
| memset(regs, 0, sizeof(regs)); | |
| struct pm_scan_arg args = {}; | |
| args.size = sizeof(args); | |
| args.start = 0; | |
| args.end = 1UL<<50; | |
| args.vec = (long)regs; | |
| args.vec_len = 1024; | |
| args.required_mask = PAGE_IS_PRESENT; | |
| args.return_mask = PAGE_IS_PRESENT; | |
| args.flags = PM_SCAN_OP_GET; | |
| ioctl(fd, PAGEMAP_SCAN, &args); | |
| return 0; | |
| } |
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| - 100.00% 0.00% a.out [kernel.vmlinux] [k] entry_SYSCALL_64_after_hwframe (inlined) ▒ | |
| entry_SYSCALL_64_after_hwframe (inlined) ▒ | |
| do_syscall_64 ▒ | |
| - do_syscall_x64 (inlined) ▒ | |
| - 100.00% __x64_sys_ioctl ▒ | |
| __se_sys_ioctl (inlined) ▒ | |
| __do_sys_ioctl (inlined) ◆ | |
| vfs_ioctl (inlined) ▒ | |
| - do_pagemap_cmd ▒ | |
| - 86.07% do_pagemap_scan ▒ | |
| - 58.50% walk_page_range ▒ | |
| + 48.10% find_vma ▒ | |
| 2.36% pagemap_scan_pte_hole ▒ | |
| 1.12% mt_find ▒ | |
| + 17.29% mmap_read_lock_killable (inlined) ▒ | |
| 2.18% find_vma ▒ | |
| 1.79% pagemap_scan_pte_hole ▒ | |
| + 0.57% mmap_read_unlock (inlined) ▒ | |
| + 10.99% up_read ▒ | |
| 1.75% down_read_killable ▒ | |
| 1.19% walk_page_range |
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