The newly-added register BPF_REG_PARAMS corresponds to bpf
register R11 in llvm. R11 is used as the base for stack arguments
so it won't mess out R10 based stacks. The kernel internal
register BPF_REG_AX was R11 previously. With this change,
BPF_REG_AX will be R12.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
 include/linux/filter.h                        |  5 +-
 kernel/bpf/core.c                             |  4 +-
 .../selftests/bpf/prog_tests/ctx_rewrite.c    | 14 ++--
 .../bpf/progs/verifier_bpf_fastcall.c         | 24 +++----
 .../selftests/bpf/progs/verifier_may_goto_1.c | 12 ++--
 .../selftests/bpf/progs/verifier_sdiv.c       | 64 +++++++++----------
 6 files changed, 62 insertions(+), 61 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index f552170eacf4..ae094328d973 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -58,8 +58,9 @@ struct ctl_table_header;
 #define BPF_REG_H	BPF_REG_9	/* hlen, callee-saved */
 
 /* Kernel hidden auxiliary/helper register. */
-#define BPF_REG_AX		MAX_BPF_REG
-#define MAX_BPF_EXT_REG		(MAX_BPF_REG + 1)
+#define BPF_REG_PARAMS		MAX_BPF_REG
+#define BPF_REG_AX		(MAX_BPF_REG + 1)
+#define MAX_BPF_EXT_REG		(MAX_BPF_REG + 2)
 #define MAX_BPF_JIT_REG		MAX_BPF_EXT_REG
 
 /* unused opcode to mark special call to bpf_tail_call() helper */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 066b86e7233c..e7e97ffa2a8b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1299,8 +1299,8 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from,
 	u32 imm_rnd = get_random_u32();
 	s16 off;
 
-	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
-	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
+	BUILD_BUG_ON(BPF_REG_PARAMS + 2 != MAX_BPF_JIT_REG);
+	BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
 
 	/* Constraints on AX register:
 	 *
diff --git a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c
index 469e92869523..83d870e32239 100644
--- a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c
+++ b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c
@@ -69,19 +69,19 @@ static struct test_case test_cases[] = {
 #if defined(__x86_64__) || defined(__aarch64__)
 	{
 		N(SCHED_CLS, struct __sk_buff, tstamp),
-		.read  = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"
-			 "if w11 & 0x4 goto pc+1;"
+		.read  = "r12 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"
+			 "if w12 & 0x4 goto pc+1;"
 			 "goto pc+4;"
-			 "if w11 & 0x3 goto pc+1;"
+			 "if w12 & 0x3 goto pc+1;"
 			 "goto pc+2;"
 			 "$dst = 0;"
 			 "goto pc+1;"
 			 "$dst = *(u64 *)($ctx + sk_buff::tstamp);",
-		.write = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"
-			 "if w11 & 0x4 goto pc+1;"
+		.write = "r12 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);"
+			 "if w12 & 0x4 goto pc+1;"
 			 "goto pc+2;"
-			 "w11 &= -4;"
-			 "*(u8 *)($ctx + sk_buff::__mono_tc_offset) = r11;"
+			 "w12 &= -4;"
+			 "*(u8 *)($ctx + sk_buff::__mono_tc_offset) = r12;"
 			 "*(u64 *)($ctx + sk_buff::tstamp) = $src;",
 	},
 #endif
diff --git a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
index fb4fa465d67c..0d9e167555b5 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bpf_fastcall.c
@@ -630,13 +630,13 @@ __xlated("...")
 __xlated("4: r0 = &(void __percpu *)(r0)")
 __xlated("...")
 /* may_goto expansion starts */
-__xlated("6: r11 = *(u64 *)(r10 -24)")
-__xlated("7: if r11 == 0x0 goto pc+6")
-__xlated("8: r11 -= 1")
-__xlated("9: if r11 != 0x0 goto pc+2")
-__xlated("10: r11 = -24")
+__xlated("6: r12 = *(u64 *)(r10 -24)")
+__xlated("7: if r12 == 0x0 goto pc+6")
+__xlated("8: r12 -= 1")
+__xlated("9: if r12 != 0x0 goto pc+2")
+__xlated("10: r12 = -24")
 __xlated("11: call unknown")
-__xlated("12: *(u64 *)(r10 -24) = r11")
+__xlated("12: *(u64 *)(r10 -24) = r12")
 /* may_goto expansion ends */
 __xlated("13: *(u64 *)(r10 -8) = r1")
 __xlated("14: exit")
@@ -668,13 +668,13 @@ __xlated("1: *(u64 *)(r10 -16) =")
 __xlated("2: r1 = 1")
 __xlated("3: call bpf_get_smp_processor_id")
 /* may_goto expansion starts */
-__xlated("4: r11 = *(u64 *)(r10 -24)")
-__xlated("5: if r11 == 0x0 goto pc+6")
-__xlated("6: r11 -= 1")
-__xlated("7: if r11 != 0x0 goto pc+2")
-__xlated("8: r11 = -24")
+__xlated("4: r12 = *(u64 *)(r10 -24)")
+__xlated("5: if r12 == 0x0 goto pc+6")
+__xlated("6: r12 -= 1")
+__xlated("7: if r12 != 0x0 goto pc+2")
+__xlated("8: r12 = -24")
 __xlated("9: call unknown")
-__xlated("10: *(u64 *)(r10 -24) = r11")
+__xlated("10: *(u64 *)(r10 -24) = r12")
 /* may_goto expansion ends */
 __xlated("11: *(u64 *)(r10 -8) = r1")
 __xlated("12: exit")
diff --git a/tools/testing/selftests/bpf/progs/verifier_may_goto_1.c b/tools/testing/selftests/bpf/progs/verifier_may_goto_1.c
index 6d1edaef9213..4bdf4256a41e 100644
--- a/tools/testing/selftests/bpf/progs/verifier_may_goto_1.c
+++ b/tools/testing/selftests/bpf/progs/verifier_may_goto_1.c
@@ -81,13 +81,13 @@ __arch_s390x
 __arch_arm64
 __xlated("0: *(u64 *)(r10 -16) = 65535")
 __xlated("1: *(u64 *)(r10 -8) = 0")
-__xlated("2: r11 = *(u64 *)(r10 -16)")
-__xlated("3: if r11 == 0x0 goto pc+6")
-__xlated("4: r11 -= 1")
-__xlated("5: if r11 != 0x0 goto pc+2")
-__xlated("6: r11 = -16")
+__xlated("2: r12 = *(u64 *)(r10 -16)")
+__xlated("3: if r12 == 0x0 goto pc+6")
+__xlated("4: r12 -= 1")
+__xlated("5: if r12 != 0x0 goto pc+2")
+__xlated("6: r12 = -16")
 __xlated("7: call unknown")
-__xlated("8: *(u64 *)(r10 -16) = r11")
+__xlated("8: *(u64 *)(r10 -16) = r12")
 __xlated("9: r0 = 1")
 __xlated("10: r0 = 2")
 __xlated("11: exit")
diff --git a/tools/testing/selftests/bpf/progs/verifier_sdiv.c b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
index fd59d57e8e37..95f3239ce228 100644
--- a/tools/testing/selftests/bpf/progs/verifier_sdiv.c
+++ b/tools/testing/selftests/bpf/progs/verifier_sdiv.c
@@ -778,10 +778,10 @@ __arch_x86_64
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r3 = -1")
 __xlated("3: r4 = r2")
-__xlated("4: r11 = r3")
-__xlated("5: r11 += 1")
-__xlated("6: if r11 > 0x1 goto pc+4")
-__xlated("7: if r11 == 0x0 goto pc+1")
+__xlated("4: r12 = r3")
+__xlated("5: r12 += 1")
+__xlated("6: if r12 > 0x1 goto pc+4")
+__xlated("7: if r12 == 0x0 goto pc+1")
 __xlated("8: r2 = 0")
 __xlated("9: r2 = -r2")
 __xlated("10: goto pc+1")
@@ -812,10 +812,10 @@ __success __retval(-5)
 __arch_x86_64
 __xlated("0: r2 = 5")
 __xlated("1: r3 = -1")
-__xlated("2: r11 = r3")
-__xlated("3: r11 += 1")
-__xlated("4: if r11 > 0x1 goto pc+4")
-__xlated("5: if r11 == 0x0 goto pc+1")
+__xlated("2: r12 = r3")
+__xlated("3: r12 += 1")
+__xlated("4: if r12 > 0x1 goto pc+4")
+__xlated("5: if r12 == 0x0 goto pc+1")
 __xlated("6: r2 = 0")
 __xlated("7: r2 = -r2")
 __xlated("8: goto pc+1")
@@ -890,10 +890,10 @@ __arch_x86_64
 __xlated("0: w2 = -2147483648")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
-__xlated("3: r11 = r3")
-__xlated("4: w11 += 1")
-__xlated("5: if w11 > 0x1 goto pc+4")
-__xlated("6: if w11 == 0x0 goto pc+1")
+__xlated("3: r12 = r3")
+__xlated("4: w12 += 1")
+__xlated("5: if w12 > 0x1 goto pc+4")
+__xlated("6: if w12 == 0x0 goto pc+1")
 __xlated("7: w2 = 0")
 __xlated("8: w2 = -w2")
 __xlated("9: goto pc+1")
@@ -925,10 +925,10 @@ __arch_x86_64
 __xlated("0: w2 = -5")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
-__xlated("3: r11 = r3")
-__xlated("4: w11 += 1")
-__xlated("5: if w11 > 0x1 goto pc+4")
-__xlated("6: if w11 == 0x0 goto pc+1")
+__xlated("3: r12 = r3")
+__xlated("4: w12 += 1")
+__xlated("5: if w12 > 0x1 goto pc+4")
+__xlated("6: if w12 == 0x0 goto pc+1")
 __xlated("7: w2 = 0")
 __xlated("8: w2 = -w2")
 __xlated("9: goto pc+1")
@@ -1004,10 +1004,10 @@ __arch_x86_64
 __xlated("0: r2 = 0x8000000000000000")
 __xlated("2: r3 = -1")
 __xlated("3: r4 = r2")
-__xlated("4: r11 = r3")
-__xlated("5: r11 += 1")
-__xlated("6: if r11 > 0x1 goto pc+3")
-__xlated("7: if r11 == 0x1 goto pc+3")
+__xlated("4: r12 = r3")
+__xlated("5: r12 += 1")
+__xlated("6: if r12 > 0x1 goto pc+3")
+__xlated("7: if r12 == 0x1 goto pc+3")
 __xlated("8: w2 = 0")
 __xlated("9: goto pc+1")
 __xlated("10: r2 s%= r3")
@@ -1034,10 +1034,10 @@ __arch_x86_64
 __xlated("0: r2 = 5")
 __xlated("1: r3 = -1")
 __xlated("2: r4 = r2")
-__xlated("3: r11 = r3")
-__xlated("4: r11 += 1")
-__xlated("5: if r11 > 0x1 goto pc+3")
-__xlated("6: if r11 == 0x1 goto pc+3")
+__xlated("3: r12 = r3")
+__xlated("4: r12 += 1")
+__xlated("5: if r12 > 0x1 goto pc+3")
+__xlated("6: if r12 == 0x1 goto pc+3")
 __xlated("7: w2 = 0")
 __xlated("8: goto pc+1")
 __xlated("9: r2 s%= r3")
@@ -1108,10 +1108,10 @@ __arch_x86_64
 __xlated("0: w2 = -2147483648")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
-__xlated("3: r11 = r3")
-__xlated("4: w11 += 1")
-__xlated("5: if w11 > 0x1 goto pc+3")
-__xlated("6: if w11 == 0x1 goto pc+4")
+__xlated("3: r12 = r3")
+__xlated("4: w12 += 1")
+__xlated("5: if w12 > 0x1 goto pc+3")
+__xlated("6: if w12 == 0x1 goto pc+4")
 __xlated("7: w2 = 0")
 __xlated("8: goto pc+1")
 __xlated("9: w2 s%= w3")
@@ -1140,10 +1140,10 @@ __arch_x86_64
 __xlated("0: w2 = -5")
 __xlated("1: w3 = -1")
 __xlated("2: w4 = w2")
-__xlated("3: r11 = r3")
-__xlated("4: w11 += 1")
-__xlated("5: if w11 > 0x1 goto pc+3")
-__xlated("6: if w11 == 0x1 goto pc+4")
+__xlated("3: r12 = r3")
+__xlated("4: w12 += 1")
+__xlated("5: if w12 > 0x1 goto pc+3")
+__xlated("6: if w12 == 0x1 goto pc+4")
 __xlated("7: w2 = 0")
 __xlated("8: goto pc+1")
 __xlated("9: w2 s%= w3")
-- 
2.52.0