From 11e456cae91e9044cb12c2b037b52c9b268925f7 Mon Sep 17 00:00:00 2001 From: Rong Tao Date: Fri, 24 Feb 2023 23:10:02 +0800 Subject: [PATCH] selftests/bpf: Fix compilation errors: Assign a value to a constant Commit bc292ab00f6c("mm: introduce vma->vm_flags wrapper functions") turns the vm_flags into a const variable. Added bpf_find_vma test in commit f108662b27c9("selftests/bpf: Add tests for bpf_find_vma") to assign values to variables that declare const in find_vma_fail1.c programs, which is an error to the compiler and does not test BPF verifiers. It is better to replace 'const vm_flags_t vm_flags' with 'unsigned long vm_start' for testing. $ make -C tools/testing/selftests/bpf/ -j8 ... progs/find_vma_fail1.c:16:16: error: cannot assign to non-static data member 'vm_flags' with const-qualified type 'const vm_flags_t' (aka 'const unsigned long') vma->vm_flags |= 0x55; ~~~~~~~~~~~~~ ^ ../tools/testing/selftests/bpf/tools/include/vmlinux.h:1898:20: note: non-static data member 'vm_flags' declared const here const vm_flags_t vm_flags; ~~~~~~~~~~~`~~~~~~^~~~~~~~ Signed-off-by: Rong Tao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/tencent_CB281722B3C1BD504C16CDE586CACC2BE706@qq.com --- tools/testing/selftests/bpf/progs/find_vma_fail1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/progs/find_vma_fail1.c b/tools/testing/selftests/bpf/progs/find_vma_fail1.c index b3b326b8e2d1..47d5dedff554 100644 --- a/tools/testing/selftests/bpf/progs/find_vma_fail1.c +++ b/tools/testing/selftests/bpf/progs/find_vma_fail1.c @@ -13,7 +13,7 @@ static long write_vma(struct task_struct *task, struct vm_area_struct *vma, struct callback_ctx *data) { /* writing to vma, which is illegal */ - vma->vm_flags |= 0x55; + vma->vm_start = 0xffffffffff600000; return 0; } -- 2.25.1