Commit 9873ce2e authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add big-endian support to the ldsx test 



Prepare the ldsx test to run on big-endian systems by adding the
necessary endianness checks around narrow memory accesses.

Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230919101336.2223655-4-iii@linux.ibm.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6cb66eca

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

+5 −1
Original line number Diff line number Diff line
@@ -104,7 +104,11 @@ int _tc(volatile struct __sk_buff *skb) 
		      "%[tmp_mark] = r1"

		      : [tmp_mark]"=r"(tmp_mark)

		      : [ctx]"r"(skb),

			[off_mark]"i"(offsetof(struct __sk_buff, mark))

			[off_mark]"i"(offsetof(struct __sk_buff, mark)

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

			+ sizeof(skb->mark) - 1

#endif

			)

		      : "r1");

#else

	tmp_mark = (char)skb->mark;

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

+85 −61
Original line number Diff line number Diff line
@@ -13,12 +13,16 @@ __description("LDSX, S8") 
__success __success_unpriv __retval(-2)

__naked void ldsx_s8(void)

{

	asm volatile ("					\

	r1 = 0x3fe;					\

	*(u64 *)(r10 - 8) = r1;				\

	r0 = *(s8 *)(r10 - 8);				\

	exit;						\

"	::: __clobber_all);

	asm volatile (

	"r1 = 0x3fe;"

	"*(u64 *)(r10 - 8) = r1;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r0 = *(s8 *)(r10 - 8);"

#else

	"r0 = *(s8 *)(r10 - 1);"

#endif

	"exit;"

	::: __clobber_all);

}



SEC("socket")
@@ -26,12 +30,16 @@ __description("LDSX, S16") 
__success __success_unpriv __retval(-2)

__naked void ldsx_s16(void)

{

	asm volatile ("					\

	r1 = 0x3fffe;					\

	*(u64 *)(r10 - 8) = r1;				\

	r0 = *(s16 *)(r10 - 8);				\

	exit;						\

"	::: __clobber_all);

	asm volatile (

	"r1 = 0x3fffe;"

	"*(u64 *)(r10 - 8) = r1;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r0 = *(s16 *)(r10 - 8);"

#else

	"r0 = *(s16 *)(r10 - 2);"

#endif

	"exit;"

	::: __clobber_all);

}



SEC("socket")
@@ -39,13 +47,17 @@ __description("LDSX, S32") 
__success __success_unpriv __retval(-1)

__naked void ldsx_s32(void)

{

	asm volatile ("					\

	r1 = 0xfffffffe;				\

	*(u64 *)(r10 - 8) = r1;				\

	r0 = *(s32 *)(r10 - 8);				\

	r0 >>= 1;					\

	exit;						\

"	::: __clobber_all);

	asm volatile (

	"r1 = 0xfffffffe;"

	"*(u64 *)(r10 - 8) = r1;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r0 = *(s32 *)(r10 - 8);"

#else

	"r0 = *(s32 *)(r10 - 4);"

#endif

	"r0 >>= 1;"

	"exit;"

	::: __clobber_all);

}



SEC("socket")
@@ -54,20 +66,24 @@ __log_level(2) __success __retval(1) 
__msg("R1_w=scalar(smin=-128,smax=127)")

__naked void ldsx_s8_range_priv(void)

{

	asm volatile ("					\

	call %[bpf_get_prandom_u32];			\

	*(u64 *)(r10 - 8) = r0;				\

	r1 = *(s8 *)(r10 - 8);				\

	/* r1 with s8 range */				\

	if r1 s> 0x7f goto l0_%=;			\

	if r1 s< -0x80 goto l0_%=;			\

	r0 = 1;						\

l1_%=:							\

	exit;						\

l0_%=:							\

	r0 = 2;						\

	goto l1_%=;					\

"	:

	asm volatile (

	"call %[bpf_get_prandom_u32];"

	"*(u64 *)(r10 - 8) = r0;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r1 = *(s8 *)(r10 - 8);"

#else

	"r1 = *(s8 *)(r10 - 1);"

#endif

	/* r1 with s8 range */

	"if r1 s> 0x7f goto l0_%=;"

	"if r1 s< -0x80 goto l0_%=;"

	"r0 = 1;"

"l1_%=:"

	"exit;"

"l0_%=:"

	"r0 = 2;"

	"goto l1_%=;"

	:

	: __imm(bpf_get_prandom_u32)

	: __clobber_all);

}
@@ -77,20 +93,24 @@ __description("LDSX, S16 range checking") 
__success __success_unpriv __retval(1)

__naked void ldsx_s16_range(void)

{

	asm volatile ("					\

	call %[bpf_get_prandom_u32];			\

	*(u64 *)(r10 - 8) = r0;				\

	r1 = *(s16 *)(r10 - 8);				\

	/* r1 with s16 range */				\

	if r1 s> 0x7fff goto l0_%=;			\

	if r1 s< -0x8000 goto l0_%=;			\

	r0 = 1;						\

l1_%=:							\

	exit;						\

l0_%=:							\

	r0 = 2;						\

	goto l1_%=;					\

"	:

	asm volatile (

	"call %[bpf_get_prandom_u32];"

	"*(u64 *)(r10 - 8) = r0;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r1 = *(s16 *)(r10 - 8);"

#else

	"r1 = *(s16 *)(r10 - 2);"

#endif

	/* r1 with s16 range */

	"if r1 s> 0x7fff goto l0_%=;"

	"if r1 s< -0x8000 goto l0_%=;"

	"r0 = 1;"

"l1_%=:"

	"exit;"

"l0_%=:"

	"r0 = 2;"

	"goto l1_%=;"

	:

	: __imm(bpf_get_prandom_u32)

	: __clobber_all);

}
@@ -100,20 +120,24 @@ __description("LDSX, S32 range checking") 
__success __success_unpriv __retval(1)

__naked void ldsx_s32_range(void)

{

	asm volatile ("					\

	call %[bpf_get_prandom_u32];			\

	*(u64 *)(r10 - 8) = r0;				\

	r1 = *(s32 *)(r10 - 8);				\

	/* r1 with s16 range */				\

	if r1 s> 0x7fffFFFF goto l0_%=;			\

	if r1 s< -0x80000000 goto l0_%=;		\

	r0 = 1;						\

l1_%=:							\

	exit;						\

l0_%=:							\

	r0 = 2;						\

	goto l1_%=;					\

"	:

	asm volatile (

	"call %[bpf_get_prandom_u32];"

	"*(u64 *)(r10 - 8) = r0;"

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	"r1 = *(s32 *)(r10 - 8);"

#else

	"r1 = *(s32 *)(r10 - 4);"

#endif

	/* r1 with s16 range */

	"if r1 s> 0x7fffFFFF goto l0_%=;"

	"if r1 s< -0x80000000 goto l0_%=;"

	"r0 = 1;"

"l1_%=:"

	"exit;"

"l0_%=:"

	"r0 = 2;"

	"goto l1_%=;"

	:

	: __imm(bpf_get_prandom_u32)

	: __clobber_all);

}