[PATCH bpf-next v2 00/10] Implement cpuv4 support for s390x

[PATCH bpf-next v2 00/10] Implement cpuv4 support for s390x

[Ilya Leoshkevich]

v1: https://lore.kernel.org/bpf/20230830011128.1415752-1-iii@linux.ibm.com/
v1 -> v2:
- Redo Disable zero-extension for BPF_MEMSX as Puranjay and Alexei
  suggested.
- Drop the bpf_ct_insert_entry() patch, it went in via the bpf tree.
- Rebase, don't apply A-bs because there were fixed conflicts.

Hi,

This series adds the cpuv4 support to the s390x eBPF JIT.
Patches 1-3 are preliminary bugfixes.
Patches 4-8 implement the new instructions.
Patches 9-10 enable the tests.

Best regards,
Ilya

Ilya Leoshkevich (10):
  bpf: Disable zero-extension for BPF_MEMSX
  selftests/bpf: Unmount the cgroup2 work directory
  selftests/bpf: Add big-endian support to the ldsx test
  s390/bpf: Implement BPF_MOV | BPF_X with sign-extension
  s390/bpf: Implement BPF_MEMSX
  s390/bpf: Implement unconditional byte swap
  s390/bpf: Implement unconditional jump with 32-bit offset
  s390/bpf: Implement signed division
  selftests/bpf: Enable the cpuv4 tests for s390x
  selftests/bpf: Trim DENYLIST.s390x

 arch/s390/net/bpf_jit_comp.c                  | 265 +++++++++++++-----
 kernel/bpf/verifier.c                         |   2 +-
 tools/testing/selftests/bpf/DENYLIST.s390x    |  25 --
 tools/testing/selftests/bpf/cgroup_helpers.c  |  33 ++-
 .../selftests/bpf/progs/test_ldsx_insn.c      |   9 +-
 .../selftests/bpf/progs/verifier_bswap.c      |   3 +-
 .../selftests/bpf/progs/verifier_gotol.c      |   3 +-
 .../selftests/bpf/progs/verifier_ldsx.c       | 149 ++++++----
 .../selftests/bpf/progs/verifier_movsx.c      |   3 +-
 .../selftests/bpf/progs/verifier_sdiv.c       |   3 +-
 10 files changed, 331 insertions(+), 164 deletions(-)

-- 
2.41.0

[PATCH bpf-next v2 01/10] bpf: Disable zero-extension for BPF_MEMSX

[Ilya Leoshkevich]

On the architectures that use bpf_jit_needs_zext(), e.g., s390x, the
verifier incorrectly inserts a zero-extension after BPF_MEMSX, leading
to miscompilations like the one below:

      24:       89 1a ff fe 00 00 00 00 "r1 = *(s16 *)(r10 - 2);"       # zext_dst set
   0x3ff7fdb910e:       lgh     %r2,-2(%r13,%r0)                        # load halfword
   0x3ff7fdb9114:       llgfr   %r2,%r2                                 # wrong!
      25:       65 10 00 03 00 00 7f ff if r1 s> 32767 goto +3 <l0_1>   # check_cond_jmp_op()

Disable such zero-extensions. The JITs need to insert sign-extension
themselves, if necessary.

Suggested-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a7178ecf676d..614bf3fa4fd5 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3114,7 +3114,7 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
 
 	if (class == BPF_LDX) {
 		if (t != SRC_OP)
-			return BPF_SIZE(code) == BPF_DW;
+			return BPF_SIZE(code) == BPF_DW || BPF_MODE(code) == BPF_MEMSX;
 		/* LDX source must be ptr. */
 		return true;
 	}
-- 
2.41.0

[PATCH bpf-next v2 02/10] selftests/bpf: Unmount the cgroup2 work directory

[Ilya Leoshkevich]

test_progs -t bind_perm,bpf_obj_pinning/mounted-str-rel fails when
the selftests directory is mounted under /mnt, which is a reasonable
thing to do when sharing the selftests residing on the host with a
virtual machine, e.g., using 9p.

The reason is that cgroup2 is mounted at /mnt and not unmounted,
causing subsequent tests that need to access the selftests directory
to fail.

Fix by unmounting it. The kernel maintains a mount stack, so this
reveals what was mounted there before. Introduce cgroup_workdir_mounted
in order to maintain idempotency. Make it thread-local in order to
support test_progs -j.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/cgroup_helpers.c | 33 +++++++++++++++-----
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index 2caee8423ee0..24ba56d42f2d 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -49,6 +49,10 @@
 	snprintf(buf, sizeof(buf), "%s%s", NETCLS_MOUNT_PATH,	\
 		 CGROUP_WORK_DIR)
 
+static __thread bool cgroup_workdir_mounted;
+
+static void __cleanup_cgroup_environment(void);
+
 static int __enable_controllers(const char *cgroup_path, const char *controllers)
 {
 	char path[PATH_MAX + 1];
@@ -209,9 +213,10 @@ int setup_cgroup_environment(void)
 		log_err("mount cgroup2");
 		return 1;
 	}
+	cgroup_workdir_mounted = true;
 
 	/* Cleanup existing failed runs, now that the environment is setup */
-	cleanup_cgroup_environment();
+	__cleanup_cgroup_environment();
 
 	if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) {
 		log_err("mkdir cgroup work dir");
@@ -305,11 +310,26 @@ int join_parent_cgroup(const char *relative_path)
 	return join_cgroup_from_top(cgroup_path);
 }
 
+/**
+ * __cleanup_cgroup_environment() - Delete temporary cgroups
+ *
+ * This is a helper for cleanup_cgroup_environment() that is responsible for
+ * deletion of all temporary cgroups that have been created during the test.
+ */
+static void __cleanup_cgroup_environment(void)
+{
+	char cgroup_workdir[PATH_MAX + 1];
+
+	format_cgroup_path(cgroup_workdir, "");
+	join_cgroup_from_top(CGROUP_MOUNT_PATH);
+	nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT);
+}
+
 /**
  * cleanup_cgroup_environment() - Cleanup Cgroup Testing Environment
  *
  * This is an idempotent function to delete all temporary cgroups that
- * have been created during the test, including the cgroup testing work
+ * have been created during the test and unmount the cgroup testing work
  * directory.
  *
  * At call time, it moves the calling process to the root cgroup, and then
@@ -320,11 +340,10 @@ int join_parent_cgroup(const char *relative_path)
  */
 void cleanup_cgroup_environment(void)
 {
-	char cgroup_workdir[PATH_MAX + 1];
-
-	format_cgroup_path(cgroup_workdir, "");
-	join_cgroup_from_top(CGROUP_MOUNT_PATH);
-	nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT);
+	__cleanup_cgroup_environment();
+	if (cgroup_workdir_mounted && umount(CGROUP_MOUNT_PATH))
+		log_err("umount cgroup2");
+	cgroup_workdir_mounted = false;
 }
 
 /**
-- 
2.41.0

[PATCH bpf-next v2 03/10] selftests/bpf: Add big-endian support to the ldsx test

[Ilya Leoshkevich]

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

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 .../selftests/bpf/progs/test_ldsx_insn.c      |   6 +-
 .../selftests/bpf/progs/verifier_ldsx.c       | 146 ++++++++++--------
 2 files changed, 90 insertions(+), 62 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
index 67c14ba1e87b..3709e5eb7dd0 100644
--- a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
+++ b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
@@ -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;
diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
index 1e1bc379c44f..97d35bc1c943 100644
--- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
@@ -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);
 }
-- 
2.41.0

[PATCH bpf-next v2 04/10] s390/bpf: Implement BPF_MOV | BPF_X with sign-extension

[Ilya Leoshkevich]

Implement the cpuv4 register-to-register move with sign extension. It
is distinguished from the normal moves by non-zero values in
insn->off, which determine the source size. s390x has instructions to
deal with all of them: lbr, lhr, lgbr, lghr and lgfr.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 48 ++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 8 deletions(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index e6a643f63ebf..fc8bbddf6533 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -795,15 +795,47 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 	/*
 	 * BPF_MOV
 	 */
-	case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
-		/* llgfr %dst,%src */
-		EMIT4(0xb9160000, dst_reg, src_reg);
-		if (insn_is_zext(&insn[1]))
-			insn_count = 2;
+	case BPF_ALU | BPF_MOV | BPF_X:
+		switch (insn->off) {
+		case 0: /* DST = (u32) SRC */
+			/* llgfr %dst,%src */
+			EMIT4(0xb9160000, dst_reg, src_reg);
+			if (insn_is_zext(&insn[1]))
+				insn_count = 2;
+			break;
+		case 8: /* DST = (u32)(s8) SRC */
+			/* lbr %dst,%src */
+			EMIT4(0xb9260000, dst_reg, src_reg);
+			/* llgfr %dst,%dst */
+			EMIT4(0xb9160000, dst_reg, dst_reg);
+			break;
+		case 16: /* DST = (u32)(s16) SRC */
+			/* lhr %dst,%src */
+			EMIT4(0xb9270000, dst_reg, src_reg);
+			/* llgfr %dst,%dst */
+			EMIT4(0xb9160000, dst_reg, dst_reg);
+			break;
+		}
 		break;
-	case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
-		/* lgr %dst,%src */
-		EMIT4(0xb9040000, dst_reg, src_reg);
+	case BPF_ALU64 | BPF_MOV | BPF_X:
+		switch (insn->off) {
+		case 0: /* DST = SRC */
+			/* lgr %dst,%src */
+			EMIT4(0xb9040000, dst_reg, src_reg);
+			break;
+		case 8: /* DST = (s8) SRC */
+			/* lgbr %dst,%src */
+			EMIT4(0xb9060000, dst_reg, src_reg);
+			break;
+		case 16: /* DST = (s16) SRC */
+			/* lghr %dst,%src */
+			EMIT4(0xb9070000, dst_reg, src_reg);
+			break;
+		case 32: /* DST = (s32) SRC */
+			/* lgfr %dst,%src */
+			EMIT4(0xb9140000, dst_reg, src_reg);
+			break;
+		}
 		break;
 	case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
 		/* llilf %dst,imm */
-- 
2.41.0

[PATCH bpf-next v2 05/10] s390/bpf: Implement BPF_MEMSX

[Ilya Leoshkevich]

Implement the cpuv4 load with sign-extension, which is encoded as
BPF_MEMSX (and, for internal uses cases only, BPF_PROBE_MEMSX).

This is the same as BPF_MEM and BPF_PROBE_MEM, but with sign
extension instead of zero extension, and s390x has the necessary
instructions: lgb, lgh and lgf.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index fc8bbddf6533..e00e7cda298f 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -670,15 +670,18 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
 static int get_probe_mem_regno(const u8 *insn)
 {
 	/*
-	 * insn must point to llgc, llgh, llgf or lg, which have destination
-	 * register at the same position.
+	 * insn must point to llgc, llgh, llgf, lg, lgb, lgh or lgf, which have
+	 * destination register at the same position.
 	 */
-	if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */
+	if (insn[0] != 0xe3) /* common prefix */
 		return -1;
 	if (insn[5] != 0x90 && /* llgc */
 	    insn[5] != 0x91 && /* llgh */
 	    insn[5] != 0x16 && /* llgf */
-	    insn[5] != 0x04) /* lg */
+	    insn[5] != 0x04 && /* lg */
+	    insn[5] != 0x77 && /* lgb */
+	    insn[5] != 0x15 && /* lgh */
+	    insn[5] != 0x14) /* lgf */
 		return -1;
 	return insn[1] >> 4;
 }
@@ -788,7 +791,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 	int err;
 
 	if (BPF_CLASS(insn->code) == BPF_LDX &&
-	    BPF_MODE(insn->code) == BPF_PROBE_MEM)
+	    (BPF_MODE(insn->code) == BPF_PROBE_MEM ||
+	     BPF_MODE(insn->code) == BPF_PROBE_MEMSX))
 		probe_prg = jit->prg;
 
 	switch (insn->code) {
@@ -1406,6 +1410,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_B: /* dst = *(s8 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
+		/* lgb %dst,0(off,%src) */
+		EMIT6_DISP_LH(0xe3000000, 0x0077, dst_reg, src_reg, REG_0, off);
+		jit->seen |= SEEN_MEM;
+		break;
 	case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_H:
 		/* llgh %dst,0(off,%src) */
@@ -1414,6 +1424,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_H: /* dst = *(s16 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
+		/* lgh %dst,0(off,%src) */
+		EMIT6_DISP_LH(0xe3000000, 0x0015, dst_reg, src_reg, REG_0, off);
+		jit->seen |= SEEN_MEM;
+		break;
 	case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_W:
 		/* llgf %dst,off(%src) */
@@ -1422,6 +1438,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_W: /* dst = *(s32 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
+		/* lgf %dst,off(%src) */
+		jit->seen |= SEEN_MEM;
+		EMIT6_DISP_LH(0xe3000000, 0x0014, dst_reg, src_reg, REG_0, off);
+		break;
 	case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
 		/* lg %dst,0(off,%src) */
-- 
2.41.0

[PATCH bpf-next v2 06/10] s390/bpf: Implement unconditional byte swap

[Ilya Leoshkevich]

Implement the cpuv4 unconditional byte swap, which is encoded as
BPF_ALU64 | BPF_END | BPF_FROM_LE. Since s390x is big-endian, it's
the same as the existing BPF_ALU | BPF_END | BPF_FROM_LE.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index e00e7cda298f..ea8ae2163109 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -1253,6 +1253,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		}
 		break;
 	case BPF_ALU | BPF_END | BPF_FROM_LE:
+	case BPF_ALU64 | BPF_END | BPF_FROM_LE:
 		switch (imm) {
 		case 16: /* dst = (u16) cpu_to_le16(dst) */
 			/* lrvr %dst,%dst */
-- 
2.41.0

[PATCH bpf-next v2 07/10] s390/bpf: Implement unconditional jump with 32-bit offset

[Ilya Leoshkevich]

Implement the cpuv4 unconditional jump with 32-bit offset, which is
encoded as BPF_JMP32 | BPF_JA and stores the offset in the imm field.
Reuse the existing BPF_JMP | BPF_JA logic.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index ea8ae2163109..55634e4c6815 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -779,6 +779,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 				 int i, bool extra_pass, u32 stack_depth)
 {
 	struct bpf_insn *insn = &fp->insnsi[i];
+	s16 branch_oc_off = insn->off;
 	u32 dst_reg = insn->dst_reg;
 	u32 src_reg = insn->src_reg;
 	int last, insn_count = 1;
@@ -1625,6 +1626,9 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 	 * instruction itself (loop) and for BPF with offset 0 we
 	 * branch to the instruction behind the branch.
 	 */
+	case BPF_JMP32 | BPF_JA: /* if (true) */
+		branch_oc_off = imm;
+		fallthrough;
 	case BPF_JMP | BPF_JA: /* if (true) */
 		mask = 0xf000; /* j */
 		goto branch_oc;
@@ -1793,14 +1797,16 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		break;
 branch_oc:
 		if (!is_first_pass(jit) &&
-		    can_use_rel(jit, addrs[i + off + 1])) {
+		    can_use_rel(jit, addrs[i + branch_oc_off + 1])) {
 			/* brc mask,off */
 			EMIT4_PCREL_RIC(0xa7040000,
-					mask >> 12, addrs[i + off + 1]);
+					mask >> 12,
+					addrs[i + branch_oc_off + 1]);
 		} else {
 			/* brcl mask,off */
 			EMIT6_PCREL_RILC(0xc0040000,
-					 mask >> 12, addrs[i + off + 1]);
+					 mask >> 12,
+					 addrs[i + branch_oc_off + 1]);
 		}
 		break;
 	}
-- 
2.41.0

[PATCH bpf-next v2 08/10] s390/bpf: Implement signed division

[Ilya Leoshkevich]

Implement the cpuv4 signed division. It is encoded as unsigned
division, but with off field set to 1. s390x has the necessary
instructions: dsgfr, dsgf and dsgr.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 172 +++++++++++++++++++++++++----------
 1 file changed, 125 insertions(+), 47 deletions(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 55634e4c6815..fd1936a63878 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -949,66 +949,115 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 	/*
 	 * BPF_DIV / BPF_MOD
 	 */
-	case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
-	case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
+	case BPF_ALU | BPF_DIV | BPF_X:
+	case BPF_ALU | BPF_MOD | BPF_X:
 	{
 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
 
-		/* lhi %w0,0 */
-		EMIT4_IMM(0xa7080000, REG_W0, 0);
-		/* lr %w1,%dst */
-		EMIT2(0x1800, REG_W1, dst_reg);
-		/* dlr %w0,%src */
-		EMIT4(0xb9970000, REG_W0, src_reg);
+		switch (off) {
+		case 0: /* dst = (u32) dst {/,%} (u32) src */
+			/* xr %w0,%w0 */
+			EMIT2(0x1700, REG_W0, REG_W0);
+			/* lr %w1,%dst */
+			EMIT2(0x1800, REG_W1, dst_reg);
+			/* dlr %w0,%src */
+			EMIT4(0xb9970000, REG_W0, src_reg);
+			break;
+		case 1: /* dst = (u32) ((s32) dst {/,%} (s32) src) */
+			/* lgfr %r1,%dst */
+			EMIT4(0xb9140000, REG_W1, dst_reg);
+			/* dsgfr %r0,%src */
+			EMIT4(0xb91d0000, REG_W0, src_reg);
+			break;
+		}
 		/* llgfr %dst,%rc */
 		EMIT4(0xb9160000, dst_reg, rc_reg);
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
 	}
-	case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
-	case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
+	case BPF_ALU64 | BPF_DIV | BPF_X:
+	case BPF_ALU64 | BPF_MOD | BPF_X:
 	{
 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
 
-		/* lghi %w0,0 */
-		EMIT4_IMM(0xa7090000, REG_W0, 0);
-		/* lgr %w1,%dst */
-		EMIT4(0xb9040000, REG_W1, dst_reg);
-		/* dlgr %w0,%dst */
-		EMIT4(0xb9870000, REG_W0, src_reg);
+		switch (off) {
+		case 0: /* dst = dst {/,%} src */
+			/* lghi %w0,0 */
+			EMIT4_IMM(0xa7090000, REG_W0, 0);
+			/* lgr %w1,%dst */
+			EMIT4(0xb9040000, REG_W1, dst_reg);
+			/* dlgr %w0,%src */
+			EMIT4(0xb9870000, REG_W0, src_reg);
+			break;
+		case 1: /* dst = (s64) dst {/,%} (s64) src */
+			/* lgr %w1,%dst */
+			EMIT4(0xb9040000, REG_W1, dst_reg);
+			/* dsgr %w0,%src */
+			EMIT4(0xb90d0000, REG_W0, src_reg);
+			break;
+		}
 		/* lgr %dst,%rc */
 		EMIT4(0xb9040000, dst_reg, rc_reg);
 		break;
 	}
-	case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
-	case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
+	case BPF_ALU | BPF_DIV | BPF_K:
+	case BPF_ALU | BPF_MOD | BPF_K:
 	{
 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
 
 		if (imm == 1) {
 			if (BPF_OP(insn->code) == BPF_MOD)
-				/* lhgi %dst,0 */
+				/* lghi %dst,0 */
 				EMIT4_IMM(0xa7090000, dst_reg, 0);
 			else
 				EMIT_ZERO(dst_reg);
 			break;
 		}
-		/* lhi %w0,0 */
-		EMIT4_IMM(0xa7080000, REG_W0, 0);
-		/* lr %w1,%dst */
-		EMIT2(0x1800, REG_W1, dst_reg);
 		if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) {
-			/* dl %w0,<d(imm)>(%l) */
-			EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
-				      EMIT_CONST_U32(imm));
+			switch (off) {
+			case 0: /* dst = (u32) dst {/,%} (u32) imm */
+				/* xr %w0,%w0 */
+				EMIT2(0x1700, REG_W0, REG_W0);
+				/* lr %w1,%dst */
+				EMIT2(0x1800, REG_W1, dst_reg);
+				/* dl %w0,<d(imm)>(%l) */
+				EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0,
+					      REG_L, EMIT_CONST_U32(imm));
+				break;
+			case 1: /* dst = (s32) dst {/,%} (s32) imm */
+				/* lgfr %r1,%dst */
+				EMIT4(0xb9140000, REG_W1, dst_reg);
+				/* dsgf %r0,<d(imm)>(%l) */
+				EMIT6_DISP_LH(0xe3000000, 0x001d, REG_W0, REG_0,
+					      REG_L, EMIT_CONST_U32(imm));
+				break;
+			}
 		} else {
-			/* lgfrl %dst,imm */
-			EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
-					 _EMIT_CONST_U32(imm));
-			jit->seen |= SEEN_LITERAL;
-			/* dlr %w0,%dst */
-			EMIT4(0xb9970000, REG_W0, dst_reg);
+			switch (off) {
+			case 0: /* dst = (u32) dst {/,%} (u32) imm */
+				/* xr %w0,%w0 */
+				EMIT2(0x1700, REG_W0, REG_W0);
+				/* lr %w1,%dst */
+				EMIT2(0x1800, REG_W1, dst_reg);
+				/* lrl %dst,imm */
+				EMIT6_PCREL_RILB(0xc40d0000, dst_reg,
+						 _EMIT_CONST_U32(imm));
+				jit->seen |= SEEN_LITERAL;
+				/* dlr %w0,%dst */
+				EMIT4(0xb9970000, REG_W0, dst_reg);
+				break;
+			case 1: /* dst = (s32) dst {/,%} (s32) imm */
+				/* lgfr %w1,%dst */
+				EMIT4(0xb9140000, REG_W1, dst_reg);
+				/* lgfrl %dst,imm */
+				EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
+						 _EMIT_CONST_U32(imm));
+				jit->seen |= SEEN_LITERAL;
+				/* dsgr %w0,%dst */
+				EMIT4(0xb90d0000, REG_W0, dst_reg);
+				break;
+			}
 		}
 		/* llgfr %dst,%rc */
 		EMIT4(0xb9160000, dst_reg, rc_reg);
@@ -1016,8 +1065,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 			insn_count = 2;
 		break;
 	}
-	case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
-	case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
+	case BPF_ALU64 | BPF_DIV | BPF_K:
+	case BPF_ALU64 | BPF_MOD | BPF_K:
 	{
 		int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
 
@@ -1027,21 +1076,50 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 				EMIT4_IMM(0xa7090000, dst_reg, 0);
 			break;
 		}
-		/* lghi %w0,0 */
-		EMIT4_IMM(0xa7090000, REG_W0, 0);
-		/* lgr %w1,%dst */
-		EMIT4(0xb9040000, REG_W1, dst_reg);
 		if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
-			/* dlg %w0,<d(imm)>(%l) */
-			EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
-				      EMIT_CONST_U64(imm));
+			switch (off) {
+			case 0: /* dst = dst {/,%} imm */
+				/* lghi %w0,0 */
+				EMIT4_IMM(0xa7090000, REG_W0, 0);
+				/* lgr %w1,%dst */
+				EMIT4(0xb9040000, REG_W1, dst_reg);
+				/* dlg %w0,<d(imm)>(%l) */
+				EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0,
+					      REG_L, EMIT_CONST_U64(imm));
+				break;
+			case 1: /* dst = (s64) dst {/,%} (s64) imm */
+				/* lgr %w1,%dst */
+				EMIT4(0xb9040000, REG_W1, dst_reg);
+				/* dsg %w0,<d(imm)>(%l) */
+				EMIT6_DISP_LH(0xe3000000, 0x000d, REG_W0, REG_0,
+					      REG_L, EMIT_CONST_U64(imm));
+				break;
+			}
 		} else {
-			/* lgrl %dst,imm */
-			EMIT6_PCREL_RILB(0xc4080000, dst_reg,
-					 _EMIT_CONST_U64(imm));
-			jit->seen |= SEEN_LITERAL;
-			/* dlgr %w0,%dst */
-			EMIT4(0xb9870000, REG_W0, dst_reg);
+			switch (off) {
+			case 0: /* dst = dst {/,%} imm */
+				/* lghi %w0,0 */
+				EMIT4_IMM(0xa7090000, REG_W0, 0);
+				/* lgr %w1,%dst */
+				EMIT4(0xb9040000, REG_W1, dst_reg);
+				/* lgrl %dst,imm */
+				EMIT6_PCREL_RILB(0xc4080000, dst_reg,
+						 _EMIT_CONST_U64(imm));
+				jit->seen |= SEEN_LITERAL;
+				/* dlgr %w0,%dst */
+				EMIT4(0xb9870000, REG_W0, dst_reg);
+				break;
+			case 1: /* dst = (s64) dst {/,%} (s64) imm */
+				/* lgr %w1,%dst */
+				EMIT4(0xb9040000, REG_W1, dst_reg);
+				/* lgrl %dst,imm */
+				EMIT6_PCREL_RILB(0xc4080000, dst_reg,
+						 _EMIT_CONST_U64(imm));
+				jit->seen |= SEEN_LITERAL;
+				/* dsgr %w0,%dst */
+				EMIT4(0xb90d0000, REG_W0, dst_reg);
+				break;
+			}
 		}
 		/* lgr %dst,%rc */
 		EMIT4(0xb9040000, dst_reg, rc_reg);
-- 
2.41.0

[PATCH bpf-next v2 09/10] selftests/bpf: Enable the cpuv4 tests for s390x

[Ilya Leoshkevich]

Now that all the cpuv4 support is in place, enable the tests.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/progs/test_ldsx_insn.c | 3 ++-
 tools/testing/selftests/bpf/progs/verifier_bswap.c | 3 ++-
 tools/testing/selftests/bpf/progs/verifier_gotol.c | 3 ++-
 tools/testing/selftests/bpf/progs/verifier_ldsx.c  | 3 ++-
 tools/testing/selftests/bpf/progs/verifier_movsx.c | 3 ++-
 tools/testing/selftests/bpf/progs/verifier_sdiv.c  | 3 ++-
 6 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
index 3709e5eb7dd0..3ddcb3777912 100644
--- a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
+++ b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
@@ -6,7 +6,8 @@
 #include <bpf/bpf_tracing.h>
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-     (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64)) && __clang_major__ >= 18
+     (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) ||       \
+     defined(__TARGET_ARCH_s390)) && __clang_major__ >= 18
 const volatile int skip = 0;
 #else
 const volatile int skip = 1;
diff --git a/tools/testing/selftests/bpf/progs/verifier_bswap.c b/tools/testing/selftests/bpf/progs/verifier_bswap.c
index 5d54f8eae6a1..107525fb4a6a 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bswap.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bswap.c
@@ -5,7 +5,8 @@
 #include "bpf_misc.h"
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || defined(__TARGET_ARCH_arm)) && \
+	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
+        defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
 	__clang_major__ >= 18
 
 SEC("socket")
diff --git a/tools/testing/selftests/bpf/progs/verifier_gotol.c b/tools/testing/selftests/bpf/progs/verifier_gotol.c
index aa54ecd5829e..9f202eda952f 100644
--- a/tools/testing/selftests/bpf/progs/verifier_gotol.c
+++ b/tools/testing/selftests/bpf/progs/verifier_gotol.c
@@ -5,7 +5,8 @@
 #include "bpf_misc.h"
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || defined(__TARGET_ARCH_arm)) && \
+	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
+        defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
 	__clang_major__ >= 18
 
 SEC("socket")
diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
index 97d35bc1c943..f90016a57eec 100644
--- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
@@ -5,7 +5,8 @@
 #include "bpf_misc.h"
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || defined(__TARGET_ARCH_arm)) && \
+	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
+        defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
 	__clang_major__ >= 18
 
 SEC("socket")
diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index ca11fd5dafd1..b2a04d1179d0 100644
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -5,7 +5,8 @@
 #include "bpf_misc.h"
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || defined(__TARGET_ARCH_arm)) && \
+	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
+        defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
 	__clang_major__ >= 18
 
 SEC("socket")
diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index fb039722b639..8fc5174808b2 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -5,7 +5,8 @@
 #include "bpf_misc.h"
 
 #if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || defined(__TARGET_ARCH_arm)) && \
+	(defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
+        defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \
 	__clang_major__ >= 18
 
 SEC("socket")
-- 
2.41.0

[PATCH bpf-next v2 10/10] selftests/bpf: Trim DENYLIST.s390x

[Ilya Leoshkevich]

Enable all selftests, except the 2 that have to do with the userspace
unwinding, and the new exceptions test, in the s390x CI.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/DENYLIST.s390x | 25 ----------------------
 1 file changed, 25 deletions(-)

diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
index ce6f291665cf..1a63996c0304 100644
--- a/tools/testing/selftests/bpf/DENYLIST.s390x
+++ b/tools/testing/selftests/bpf/DENYLIST.s390x
@@ -1,30 +1,5 @@
 # TEMPORARY
 # Alphabetical order
-bloom_filter_map                         # failed to find kernel BTF type ID of '__x64_sys_getpgid': -3                (?)
-bpf_cookie                               # failed to open_and_load program: -524 (trampoline)
-bpf_loop                                 # attaches to __x64_sys_nanosleep
-cgrp_local_storage                       # prog_attach unexpected error: -524                                          (trampoline)
-dynptr/test_dynptr_skb_data
-dynptr/test_skb_readonly
 exceptions				 # JIT does not support calling kfunc bpf_throw				       (exceptions)
-fexit_sleep                              # fexit_skel_load fexit skeleton failed                                       (trampoline)
 get_stack_raw_tp                         # user_stack corrupted user stack                                             (no backchain userspace)
-iters/testmod_seq*                       # s390x doesn't support kfuncs in modules yet
-kprobe_multi_bench_attach                # bpf_program__attach_kprobe_multi_opts unexpected error: -95
-kprobe_multi_test                        # relies on fentry
-ksyms_btf/weak_ksyms*                    # test_ksyms_weak__open_and_load unexpected error: -22                        (kfunc)
-ksyms_module                             # test_ksyms_module__open_and_load unexpected error: -9                       (?)
-ksyms_module_libbpf                      # JIT does not support calling kernel function                                (kfunc)
-ksyms_module_lskel                       # test_ksyms_module_lskel__open_and_load unexpected error: -9                 (?)
-module_attach                            # skel_attach skeleton attach failed: -524                                    (trampoline)
-ringbuf                                  # skel_load skeleton load failed                                              (?)
 stacktrace_build_id                      # compare_map_keys stackid_hmap vs. stackmap err -2 errno 2                   (?)
-test_lsm                                 # attach unexpected error: -524                                               (trampoline)
-trace_printk                             # trace_printk__load unexpected error: -2 (errno 2)                           (?)
-trace_vprintk                            # trace_vprintk__open_and_load unexpected error: -9                           (?)
-unpriv_bpf_disabled                      # fentry
-user_ringbuf                             # failed to find kernel BTF type ID of '__s390x_sys_prctl': -3                (?)
-verif_stats                              # trace_vprintk__open_and_load unexpected error: -9                           (?)
-xdp_bonding                              # failed to auto-attach program 'trace_on_entry': -524                        (trampoline)
-xdp_metadata                             # JIT does not support calling kernel function                                (kfunc)
-test_task_under_cgroup                   # JIT does not support calling kernel function                                (kfunc)
-- 
2.41.0

Re: [PATCH bpf-next v2 01/10] bpf: Disable zero-extension for BPF_MEMSX

[Puranjay Mohan]

Ilya Leoshkevich <iii@linux.ibm.com> writes:

> On the architectures that use bpf_jit_needs_zext(), e.g., s390x, the
> verifier incorrectly inserts a zero-extension after BPF_MEMSX, leading
> to miscompilations like the one below:
>
>       24:       89 1a ff fe 00 00 00 00 "r1 = *(s16 *)(r10 - 2);"       # zext_dst set
>    0x3ff7fdb910e:       lgh     %r2,-2(%r13,%r0)                        # load halfword
>    0x3ff7fdb9114:       llgfr   %r2,%r2                                 # wrong!
>       25:       65 10 00 03 00 00 7f ff if r1 s> 32767 goto +3 <l0_1>   # check_cond_jmp_op()
>
> Disable such zero-extensions. The JITs need to insert sign-extension
> themselves, if necessary.
>
> Suggested-by: Puranjay Mohan <puranjay12@gmail.com>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>  kernel/bpf/verifier.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index a7178ecf676d..614bf3fa4fd5 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -3114,7 +3114,7 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
>  
>  	if (class == BPF_LDX) {
>  		if (t != SRC_OP)
> -			return BPF_SIZE(code) == BPF_DW;
> +			return BPF_SIZE(code) == BPF_DW || BPF_MODE(code) == BPF_MEMSX;
>  		/* LDX source must be ptr. */
>  		return true;
>  	}
> -- 
> 2.41.0

Reviewed-by: Puranjay Mohan <puranjay12@gmail.com>

Thanks for this.
Puranjay

Re: [PATCH bpf-next v2 00/10] Implement cpuv4 support for s390x

[patchwork-bot+netdevbpf]

Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Tue, 19 Sep 2023 12:09:02 +0200 you wrote:
> v1: https://lore.kernel.org/bpf/20230830011128.1415752-1-iii@linux.ibm.com/
> v1 -> v2:
> - Redo Disable zero-extension for BPF_MEMSX as Puranjay and Alexei
>   suggested.
> - Drop the bpf_ct_insert_entry() patch, it went in via the bpf tree.
> - Rebase, don't apply A-bs because there were fixed conflicts.
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2,01/10] bpf: Disable zero-extension for BPF_MEMSX
    https://git.kernel.org/bpf/bpf-next/c/577c06af8188
  - [bpf-next,v2,02/10] selftests/bpf: Unmount the cgroup2 work directory
    https://git.kernel.org/bpf/bpf-next/c/6cb66eca36f3
  - [bpf-next,v2,03/10] selftests/bpf: Add big-endian support to the ldsx test
    https://git.kernel.org/bpf/bpf-next/c/9873ce2e9c68
  - [bpf-next,v2,04/10] s390/bpf: Implement BPF_MOV | BPF_X with sign-extension
    https://git.kernel.org/bpf/bpf-next/c/3de55893f648
  - [bpf-next,v2,05/10] s390/bpf: Implement BPF_MEMSX
    https://git.kernel.org/bpf/bpf-next/c/738476a079bd
  - [bpf-next,v2,06/10] s390/bpf: Implement unconditional byte swap
    https://git.kernel.org/bpf/bpf-next/c/90f426d35e01
  - [bpf-next,v2,07/10] s390/bpf: Implement unconditional jump with 32-bit offset
    https://git.kernel.org/bpf/bpf-next/c/c690191e23d8
  - [bpf-next,v2,08/10] s390/bpf: Implement signed division
    https://git.kernel.org/bpf/bpf-next/c/91d2ad78e90c
  - [bpf-next,v2,09/10] selftests/bpf: Enable the cpuv4 tests for s390x
    https://git.kernel.org/bpf/bpf-next/c/48c432382dd4
  - [bpf-next,v2,10/10] selftests/bpf: Trim DENYLIST.s390x
    https://git.kernel.org/bpf/bpf-next/c/c29913bbf4ec

You are awesome, thank you!
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