From: Rong Tao rongtao@cestc.cn

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 rongtao@cestc.cn --- v2: Add more useful commit information v1: https://lore.kernel.org/lkml/tencent_FC8827062142CF5936974B2A30AF6CA3C408@qq... --- 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; }