netdev - [PATCH bpf 2/3] bpf: show real jited address in bpf_prog_info->jited

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Message-ID: <20181101070058.2760251-3-songliubraving@fb.com>
Date:   Thu, 1 Nov 2018 00:00:57 -0700
From:   Song Liu <songliubraving@...com>
To:     <netdev@...r.kernel.org>
CC:     <kernel-team@...com>, Song Liu <songliubraving@...com>,
        <ast@...nel.org>, <daniel@...earbox.net>,
        <sandipan@...ux.vnet.ibm.com>
Subject: [PATCH bpf 2/3] bpf: show real jited address in bpf_prog_info->jited_ksyms

Currently, jited_ksyms in bpf_prog_info shows page addresses of jited
bpf program. This is not ideal for detailed profiling (find hot
instructions from stack traces). This patch replaces the page address
with real prog start address.

Signed-off-by: Song Liu <songliubraving@...com>
---
 kernel/bpf/syscall.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ccb93277aae2..34a9eef5992c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2172,7 +2172,6 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
 			for (i = 0; i < ulen; i++) {
 				ksym_addr = (ulong) prog->aux->func[i]->bpf_func;
-				ksym_addr &= PAGE_MASK;
 				if (put_user((u64) ksym_addr, &user_ksyms[i]))
 					return -EFAULT;
 			}
-- 
2.17.1