[PATCH bpf-next v3 1/6] bpf: Unify data extension operation of jited_ksyms and jited_linfo

Pu Lehui pulehui at huawei.com
Mon May 30 02:28:10 PDT 2022


We found that 32-bit environment can not print bpf line info due
to data inconsistency between jited_ksyms[0] and jited_linfo[0].

For example:
jited_kyms[0] = 0xb800067c, jited_linfo[0] = 0xffffffffb800067c

We know that both of them store bpf func address, but due to the
different data extension operations when extended to u64, they may
not be the same. We need to unify the data extension operations of
them.

Signed-off-by: Pu Lehui <pulehui at huawei.com>
---
 kernel/bpf/syscall.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e0aead17dff4..2929a4aab82c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4095,14 +4095,15 @@ static int bpf_prog_get_info_by_fd(struct file *file,
 		info.nr_jited_line_info = 0;
 	if (info.nr_jited_line_info && ulen) {
 		if (bpf_dump_raw_ok(file->f_cred)) {
+			unsigned long ladd;
 			__u64 __user *user_linfo;
 			u32 i;
 
 			user_linfo = u64_to_user_ptr(info.jited_line_info);
 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
 			for (i = 0; i < ulen; i++) {
-				if (put_user((__u64)(long)prog->aux->jited_linfo[i],
-					     &user_linfo[i]))
+				ladd = (unsigned long)prog->aux->jited_linfo[i];
+				if (put_user((__u64)ladd, &user_linfo[i]))
 					return -EFAULT;
 			}
 		} else {
-- 
2.25.1




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