Commit 1193c46c authored by Amery Hung's avatar Amery Hung Committed by Martin KaFai Lau
Browse files

selftests/bpf: Test changing packet data from global functions with a kfunc 



The verifier should invalidate all packet pointers after a packet data
changing kfunc is called. So, similar to commit 3f23ee55
("selftests/bpf: test for changing packet data from global functions"),
test changing packet data from global functions to make sure packet
pointers are indeed invalidated.

Signed-off-by: default avatarAmery Hung <ameryhung@gmail.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250925170013.1752561-2-ameryhung@gmail.com
parent bc8712f2

tools/testing/selftests/bpf/progs/verifier_sock.c

+29 −1
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Converted from tools/testing/selftests/bpf/verifier/sock.c */



#include <linux/bpf.h>

#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include "bpf_misc.h"
@@ -1068,6 +1068,34 @@ int invalidate_pkt_pointers_from_global_func(struct __sk_buff *sk) 
	return TCX_PASS;

}



__noinline

long xdp_pull_data2(struct xdp_md *x, __u32 len)

{

	return bpf_xdp_pull_data(x, len);

}



__noinline

long xdp_pull_data1(struct xdp_md *x, __u32 len)

{

	return xdp_pull_data2(x, len);

}



/* global function calls bpf_xdp_pull_data(), which invalidates packet

 * pointers established before global function call.

 */

SEC("xdp")

__failure __msg("invalid mem access")

int invalidate_xdp_pkt_pointers_from_global_func(struct xdp_md *x)

{

	int *p = (void *)(long)x->data;



	if ((void *)(p + 1) > (void *)(long)x->data_end)

		return XDP_DROP;

	xdp_pull_data1(x, 0);

	*p = 42; /* this is unsafe */

	return XDP_PASS;

}



__noinline

int tail_call(struct __sk_buff *sk)

{