Commit c4b1be92 authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Alexei Starovoitov
Browse files

selftests/bpf: bpf_rdonly_cast u{8,16,32,64} access tests 



Tests with aligned and misaligned memory access of different sizes via
pointer returned by bpf_rdonly_cast().

Suggested-by: default avatarAndrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250627015539.1439656-1-eddyz87@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ffaff180

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

+41 −0
Original line number Diff line number Diff line
@@ -133,4 +133,45 @@ int mixed_mem_type(void *ctx) 
	return *p;

}



__attribute__((__aligned__(8)))

u8 global[] = {

	0x11, 0x22, 0x33, 0x44,

	0x55, 0x66, 0x77, 0x88,

	0x99

};



__always_inline

static u64 combine(void *p)

{

	u64 acc;



	acc = 0;

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	acc |= (*(u64 *)p >> 56) << 24;

	acc |= (*(u32 *)p >> 24) << 16;

	acc |= (*(u16 *)p >> 8)  << 8;

	acc |= *(u8 *)p;

#else

	acc |= (*(u64 *)p & 0xff) << 24;

	acc |= (*(u32 *)p & 0xff) << 16;

	acc |= (*(u16 *)p & 0xff) << 8;

	acc |= *(u8 *)p;

#endif

	return acc;

}



SEC("socket")

__retval(0x88442211)

int diff_size_access(void *ctx)

{

	return combine(bpf_rdonly_cast(&global, 0));

}



SEC("socket")

__retval(0x99553322)

int misaligned_access(void *ctx)

{

	return combine(bpf_rdonly_cast(&global, 0) + 1);

}



char _license[] SEC("license") = "GPL";