Merge branch 'First set of verifier/*.c migrated to inline assembly'

Eduard Zingerman says:

====================

This is a follow up for RFC [1]. It migrates a first batch of 38
verifier/*.c tests to inline assembly and use of ./test_progs for
actual execution. The migration is done by a python script (see [2]).

Each migrated verifier/xxx.c file is mapped to progs/verifier_xxx.c
plus an entry in the prog_tests/verifier.c. One patch per each file.

A few patches at the beginning of the patch-set extend test_loader
with necessary functionality, mainly:
- support for tests execution in unprivileged mode;
- support for test runs for test programs.

Migrated tests could be selected for execution using the following filter:

  ./test_progs -a verifier_*

An example of the migrated test:

  SEC("xdp")
  __description("XDP pkt read, pkt_data' > pkt_end, corner case, good access")
  __success __retval(0) __flag(BPF_F_ANY_ALIGNMENT)
  __naked void end_corner_case_good_access_1(void)
  {
          asm volatile ("                                 \
          r2 = *(u32*)(r1 + %[xdp_md_data]);              \
          r3 = *(u32*)(r1 + %[xdp_md_data_end]);          \
          r1 = r2;                                        \
          r1 += 8;                                        \
          if r1 > r3 goto l0_%=;                          \
          r0 = *(u64*)(r1 - 8);                           \
  l0_%=:  r0 = 0;                                         \
          exit;                                           \
  "       :
          : __imm_const(xdp_md_data, offsetof(struct xdp_md, data)),
            __imm_const(xdp_md_data_end, offsetof(struct xdp_md, data_end))
          : __clobber_all);
  }

Changes compared to RFC:
- test_loader.c is extended to support test program runs;
- capabilities handling now matches behavior of test_verifier;
- BPF_ST_MEM instructions are automatically replaced by BPF_STX_MEM
  instructions to overcome current clang limitations;
- tests styling updates according to RFC feedback;
- 38 migrated files are included instead of 1.

I used the following means for testing:
- migration tool itself has a set of self-tests;
- migrated tests are passing;
- manually compared each old/new file side-by-side.

While doing side-by-side comparison I've noted a few defects in the
original tests:
- and.c:
  - One of the jump targets is off by one;
  - BPF_ST_MEM wrong OFF/IMM ordering;
- array_access.c:
  - BPF_ST_MEM wrong OFF/IMM ordering;
- value_or_null.c:
  - BPF_ST_MEM wrong OFF/IMM ordering.

These defects would be addressed separately.

[1] RFC
    https://lore.kernel.org/bpf/20230123145148.2791939-1-eddyz87@gmail.com/
[2] Migration tool
    https://github.com/eddyz87/verifier-tests-migrator
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 484 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
new file mode 100644
index 000000000000..e0f77e3e7869
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
@@ -0,0 +1,484 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/stack_ptr.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <limits.h>
+#include "bpf_misc.h"
+
+#define MAX_ENTRIES 11
+
+struct test_val {
+	unsigned int index;
+	int foo[MAX_ENTRIES];
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, struct test_val);
+} map_array_48b SEC(".maps");
+
+SEC("socket")
+__description("PTR_TO_STACK store/load")
+__success __success_unpriv __retval(0xfaceb00c)
+__naked void ptr_to_stack_store_load(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -10;					\
+	r0 = 0xfaceb00c;				\
+	*(u64*)(r1 + 2) = r0;				\
+	r0 = *(u64*)(r1 + 2);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK store/load - bad alignment on off")
+__failure __msg("misaligned stack access off (0x0; 0x0)+-8+2 size 8")
+__failure_unpriv
+__naked void load_bad_alignment_on_off(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -8;					\
+	r0 = 0xfaceb00c;				\
+	*(u64*)(r1 + 2) = r0;				\
+	r0 = *(u64*)(r1 + 2);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK store/load - bad alignment on reg")
+__failure __msg("misaligned stack access off (0x0; 0x0)+-10+8 size 8")
+__failure_unpriv
+__naked void load_bad_alignment_on_reg(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -10;					\
+	r0 = 0xfaceb00c;				\
+	*(u64*)(r1 + 8) = r0;				\
+	r0 = *(u64*)(r1 + 8);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK store/load - out of bounds low")
+__failure __msg("invalid write to stack R1 off=-79992 size=8")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void load_out_of_bounds_low(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -80000;					\
+	r0 = 0xfaceb00c;				\
+	*(u64*)(r1 + 8) = r0;				\
+	r0 = *(u64*)(r1 + 8);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK store/load - out of bounds high")
+__failure __msg("invalid write to stack R1 off=0 size=8")
+__failure_unpriv
+__naked void load_out_of_bounds_high(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -8;					\
+	r0 = 0xfaceb00c;				\
+	*(u64*)(r1 + 8) = r0;				\
+	r0 = *(u64*)(r1 + 8);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 1")
+__success __success_unpriv __retval(42)
+__naked void to_stack_check_high_1(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -1;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 2")
+__success __success_unpriv __retval(42)
+__naked void to_stack_check_high_2(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r0 = 42;					\
+	*(u8*)(r1 - 1) = r0;				\
+	r0 = *(u8*)(r1 - 1);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 3")
+__success __failure_unpriv
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__retval(42)
+__naked void to_stack_check_high_3(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += 0;					\
+	r0 = 42;					\
+	*(u8*)(r1 - 1) = r0;				\
+	r0 = *(u8*)(r1 - 1);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 4")
+__failure __msg("invalid write to stack R1 off=0 size=1")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_high_4(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += 0;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 5")
+__failure __msg("invalid write to stack R1")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_high_5(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, (1 << 29) - 1)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 6")
+__failure __msg("invalid write to stack")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_high_6(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1 + %[shrt_max]) = r0;			\
+	r0 = *(u8*)(r1 + %[shrt_max]);			\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, (1 << 29) - 1),
+	  __imm_const(shrt_max, SHRT_MAX)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check high 7")
+__failure __msg("fp pointer offset")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_high_7(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1 + %[shrt_max]) = r0;			\
+	r0 = *(u8*)(r1 + %[shrt_max]);			\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, (1 << 29) - 1),
+	  __imm_const(shrt_max, SHRT_MAX)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 1")
+__success __success_unpriv __retval(42)
+__naked void to_stack_check_low_1(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -512;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 2")
+__success __failure_unpriv
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__retval(42)
+__naked void to_stack_check_low_2(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -513;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 1) = r0;				\
+	r0 = *(u8*)(r1 + 1);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 3")
+__failure __msg("invalid write to stack R1 off=-513 size=1")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_low_3(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -513;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 4")
+__failure __msg("math between fp pointer")
+__failure_unpriv
+__naked void to_stack_check_low_4(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[int_min];				\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	:
+	: __imm_const(int_min, INT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 5")
+__failure __msg("invalid write to stack")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_low_5(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, -((1 << 29) - 1))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 6")
+__failure __msg("invalid write to stack")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_low_6(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1  %[shrt_min]) = r0;			\
+	r0 = *(u8*)(r1  %[shrt_min]);			\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, -((1 << 29) - 1)),
+	  __imm_const(shrt_min, SHRT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK check low 7")
+__failure __msg("fp pointer offset")
+__msg_unpriv("R1 stack pointer arithmetic goes out of range")
+__naked void to_stack_check_low_7(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += %[__imm_0];				\
+	r1 += %[__imm_0];				\
+	r0 = 42;					\
+	*(u8*)(r1  %[shrt_min]) = r0;			\
+	r0 = *(u8*)(r1  %[shrt_min]);			\
+	exit;						\
+"	:
+	: __imm_const(__imm_0, -((1 << 29) - 1)),
+	  __imm_const(shrt_min, SHRT_MIN)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK mixed reg/k, 1")
+__success __success_unpriv __retval(42)
+__naked void stack_mixed_reg_k_1(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -3;					\
+	r2 = -3;					\
+	r1 += r2;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK mixed reg/k, 2")
+__success __success_unpriv __retval(42)
+__naked void stack_mixed_reg_k_2(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u64*)(r10 - 8) = r0;				\
+	r0 = 0;						\
+	*(u64*)(r10 - 16) = r0;				\
+	r1 = r10;					\
+	r1 += -3;					\
+	r2 = -3;					\
+	r1 += r2;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r5 = r10;					\
+	r0 = *(u8*)(r5 - 6);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK mixed reg/k, 3")
+__success __success_unpriv __retval(-3)
+__naked void stack_mixed_reg_k_3(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r1 += -3;					\
+	r2 = -3;					\
+	r1 += r2;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = r2;					\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("PTR_TO_STACK reg")
+__success __success_unpriv __retval(42)
+__naked void ptr_to_stack_reg(void)
+{
+	asm volatile ("					\
+	r1 = r10;					\
+	r2 = -3;					\
+	r1 += r2;					\
+	r0 = 42;					\
+	*(u8*)(r1 + 0) = r0;				\
+	r0 = *(u8*)(r1 + 0);				\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("socket")
+__description("stack pointer arithmetic")
+__success __success_unpriv __retval(0)
+__naked void stack_pointer_arithmetic(void)
+{
+	asm volatile ("					\
+	r1 = 4;						\
+	goto l0_%=;					\
+l0_%=:	r7 = r10;					\
+	r7 += -10;					\
+	r7 += -10;					\
+	r2 = r7;					\
+	r2 += r1;					\
+	r0 = 0;						\
+	*(u32*)(r2 + 4) = r0;				\
+	r2 = r7;					\
+	r2 += 8;					\
+	r0 = 0;						\
+	*(u32*)(r2 + 4) = r0;				\
+	r0 = 0;						\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("tc")
+__description("store PTR_TO_STACK in R10 to array map using BPF_B")
+__success __retval(42)
+__naked void array_map_using_bpf_b(void)
+{
+	asm volatile ("					\
+	/* Load pointer to map. */			\
+	r2 = r10;					\
+	r2 += -8;					\
+	r1 = 0;						\
+	*(u64*)(r2 + 0) = r1;				\
+	r1 = %[map_array_48b] ll;			\
+	call %[bpf_map_lookup_elem];			\
+	if r0 != 0 goto l0_%=;				\
+	r0 = 2;						\
+	exit;						\
+l0_%=:	r1 = r0;					\
+	/* Copy R10 to R9. */				\
+	r9 = r10;					\
+	/* Pollute other registers with unaligned values. */\
+	r2 = -1;					\
+	r3 = -1;					\
+	r4 = -1;					\
+	r5 = -1;					\
+	r6 = -1;					\
+	r7 = -1;					\
+	r8 = -1;					\
+	/* Store both R9 and R10 with BPF_B and read back. */\
+	*(u8*)(r1 + 0) = r10;				\
+	r2 = *(u8*)(r1 + 0);				\
+	*(u8*)(r1 + 0) = r9;				\
+	r3 = *(u8*)(r1 + 0);				\
+	/* Should read back as same value. */		\
+	if r2 == r3 goto l1_%=;				\
+	r0 = 1;						\
+	exit;						\
+l1_%=:	r0 = 42;					\
+	exit;						\
+"	:
+	: __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_array_48b)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";