mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
14f1aae17e
Add selftest validating various aspects of statically linking global
variables:
- correct resolution of extern variables across .bss, .data, and .rodata
sections;
- correct handling of weak definitions;
- correct de-duplication of repeating special externs (.kconfig, .ksyms).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-17-andrii@kernel.org
56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2021 Facebook */
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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extern int LINUX_KERNEL_VERSION __kconfig;
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/* when an extern is defined as both strong and weak, resulting symbol will be strong */
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extern bool CONFIG_BPF_SYSCALL __kconfig;
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extern const void __start_BTF __ksym;
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int input_bss2;
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int input_data2 = 2;
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const volatile int input_rodata2 = 22;
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int input_bss_weak __weak;
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/* these two weak variables should lose */
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int input_data_weak __weak = 20;
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const volatile int input_rodata_weak __weak = 200;
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extern int input_bss1;
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extern int input_data1;
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extern const int input_rodata1;
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int output_bss2;
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int output_data2;
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int output_rodata2;
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int output_sink2;
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static __noinline int get_data_res(void)
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{
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/* just make sure all the relocations work against .text as well */
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return input_data1 + input_data2 + input_data_weak;
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}
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SEC("raw_tp/sys_enter")
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int BPF_PROG(handler2)
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{
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output_bss2 = input_bss1 + input_bss2 + input_bss_weak;
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output_data2 = get_data_res();
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output_rodata2 = input_rodata1 + input_rodata2 + input_rodata_weak;
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/* make sure we actually use above special externs, otherwise compiler
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* will optimize them out
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*/
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output_sink2 = LINUX_KERNEL_VERSION
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+ CONFIG_BPF_SYSCALL
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+ (long)&__start_BTF;
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return 0;
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}
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char LICENSE[] SEC("license") = "GPL";
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