| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* Copyright (c) 2021 Facebook */ |
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| 3 | #include "vmlinux.h" |
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| 4 | #include <bpf/bpf_helpers.h> |
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| 5 | #define vm_flags vm_start |
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| 6 | |
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| 7 | char _license[] SEC("license" ) = "GPL" ; |
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| 8 | |
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| 9 | struct callback_ctx { |
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| 10 | int dummy; |
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| 11 | }; |
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| 12 | |
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| 13 | static long write_vma(struct task_struct *task, struct vm_area_struct *vma, |
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| 14 | struct callback_ctx *data) |
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| 15 | { |
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| 16 | /* writing to vma, which is illegal */ |
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| 17 | vma->vm_start = 0xffffffffff600000; |
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| 18 | |
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| 19 | return 0; |
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| 20 | } |
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| 21 | |
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| 22 | SEC("raw_tp/sys_enter" ) |
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| 23 | int handle_getpid(void) |
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| 24 | { |
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| 25 | struct task_struct *task = bpf_get_current_task_btf(); |
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| 26 | struct callback_ctx data = {}; |
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| 27 | |
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| 28 | bpf_find_vma(task, 0, write_vma, &data, 0); |
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| 29 | return 0; |
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| 30 | } |
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| 31 | |
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