[PATCH bpf-next 1/3] bpf: Use precise image size for struct_ops trampoline
Pu Lehui
pulehui at huaweicloud.com
Tue Jan 23 02:32:39 PST 2024
From: Pu Lehui <pulehui at huawei.com>
For trampoline using bpf_prog_pack, we need to generate a rw_image
buffer with size of (image_end - image). For regular trampoline, we use
the precise image size generated by arch_bpf_trampoline_size to allocate
rw_image. But for struct_ops trampoline, we allocate rw_image directly
using close to PAGE_SIZE size. We do not need to allocate for that much,
as the patch size is usually much smaller than PAGE_SIZE. Let's use
precise image size for it too.
Signed-off-by: Pu Lehui <pulehui at huawei.com>
---
kernel/bpf/bpf_struct_ops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 02068bd0e4d9..e2e1bf3c69a3 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -368,7 +368,7 @@ int bpf_struct_ops_prepare_trampoline(struct bpf_tramp_links *tlinks,
return size;
if (size > (unsigned long)image_end - (unsigned long)image)
return -E2BIG;
- return arch_prepare_bpf_trampoline(NULL, image, image_end,
+ return arch_prepare_bpf_trampoline(NULL, image, image + size,
model, flags, tlinks, stub_func);
}
--
2.34.1
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