Some private stack tests are added including:
- main prog only with stack size greater than BPF_PSTACK_MIN_SIZE.
- main prog only with stack size smaller than BPF_PSTACK_MIN_SIZE.
- prog with one subprog having MAX_BPF_STACK stack size and another
subprog having non-zero small stack size.
- prog with callback function.
- prog with exception in main prog or subprog.
- prog with async callback without nesting
- prog with async callback with possible nesting
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/verifier.c | 2 +
.../bpf/progs/verifier_private_stack.c | 272 ++++++++++++++++++
2 files changed, 274 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/verifier_private_stack.c
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 75f7a2ce334b..d9f65adb456b 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -61,6 +61,7 @@
#include "verifier_or_jmp32_k.skel.h"
#include "verifier_precision.skel.h"
#include "verifier_prevent_map_lookup.skel.h"
+#include "verifier_private_stack.skel.h"
#include "verifier_raw_stack.skel.h"
#include "verifier_raw_tp_writable.skel.h"
#include "verifier_reg_equal.skel.h"
@@ -188,6 +189,7 @@ void test_verifier_bpf_fastcall(void) { RUN(verifier_bpf_fastcall); }
void test_verifier_or_jmp32_k(void) { RUN(verifier_or_jmp32_k); }
void test_verifier_precision(void) { RUN(verifier_precision); }
void test_verifier_prevent_map_lookup(void) { RUN(verifier_prevent_map_lookup); }
+void test_verifier_private_stack(void) { RUN(verifier_private_stack); }
void test_verifier_raw_stack(void) { RUN(verifier_raw_stack); }
void test_verifier_raw_tp_writable(void) { RUN(verifier_raw_tp_writable); }
void test_verifier_reg_equal(void) { RUN(verifier_reg_equal); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_private_stack.c b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
new file mode 100644
index 000000000000..b1fbdf119553
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_private_stack.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+#include "bpf_experimental.h"
+
+/* From include/linux/filter.h */
+#define MAX_BPF_STACK 512
+
+#if defined(__TARGET_ARCH_x86)
+
+struct elem {
+ struct bpf_timer t;
+ char pad[256];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, struct elem);
+} array SEC(".maps");
+
+SEC("kprobe")
+__description("Private stack, single prog")
+__success
+__arch_x86_64
+__jited(" movabsq $0x{{.*}}, %r9")
+__jited(" addq %gs:0x{{.*}}, %r9")
+__jited(" movl $0x2a, %edi")
+__jited(" movq %rdi, -0x100(%r9)")
+__naked void private_stack_single_prog(void)
+{
+ asm volatile (" \
+ r1 = 42; \
+ *(u64 *)(r10 - 256) = r1; \
+ r0 = 0; \
+ exit; \
+" ::: __clobber_all);
+}
+
+SEC("raw_tp")
+__description("No private stack")
+__success
+__arch_x86_64
+__jited(" subq $0x8, %rsp")
+__naked void no_private_stack_nested(void)
+{
+ asm volatile (" \
+ r1 = 42; \
+ *(u64 *)(r10 - 8) = r1; \
+ r0 = 0; \
+ exit; \
+" ::: __clobber_all);
+}
+
+__used
+__naked static void cumulative_stack_depth_subprog(void)
+{
+ asm volatile (" \
+ r1 = 41; \
+ *(u64 *)(r10 - 32) = r1; \
+ call %[bpf_get_smp_processor_id]; \
+ exit; \
+" :
+ : __imm(bpf_get_smp_processor_id)
+ : __clobber_all);
+}
+
+SEC("kprobe")
+__description("Private stack, subtree > MAX_BPF_STACK")
+__success
+__arch_x86_64
+/* private stack fp for the main prog */
+__jited(" movabsq $0x{{.*}}, %r9")
+__jited(" addq %gs:0x{{.*}}, %r9")
+__jited(" movl $0x2a, %edi")
+__jited(" movq %rdi, -0x200(%r9)")
+__jited(" pushq %r9")
+__jited(" callq 0x{{.*}}")
+__jited(" popq %r9")
+__jited(" xorl %eax, %eax")
+__naked void private_stack_nested_1(void)
+{
+ asm volatile (" \
+ r1 = 42; \
+ *(u64 *)(r10 - %[max_bpf_stack]) = r1; \
+ call cumulative_stack_depth_subprog; \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm_const(max_bpf_stack, MAX_BPF_STACK)
+ : __clobber_all);
+}
+
+__naked __noinline __used
+static unsigned long loop_callback(void)
+{
+ asm volatile (" \
+ call %[bpf_get_prandom_u32]; \
+ r1 = 42; \
+ *(u64 *)(r10 - 512) = r1; \
+ call cumulative_stack_depth_subprog; \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_common);
+}
+
+SEC("raw_tp")
+__description("Private stack, callback")
+__success
+__arch_x86_64
+/* for func loop_callback */
+__jited("func #1")
+__jited(" endbr64")
+__jited(" nopl (%rax,%rax)")
+__jited(" nopl (%rax)")
+__jited(" pushq %rbp")
+__jited(" movq %rsp, %rbp")
+__jited(" endbr64")
+__jited(" movabsq $0x{{.*}}, %r9")
+__jited(" addq %gs:0x{{.*}}, %r9")
+__jited(" pushq %r9")
+__jited(" callq")
+__jited(" popq %r9")
+__jited(" movl $0x2a, %edi")
+__jited(" movq %rdi, -0x200(%r9)")
+__jited(" pushq %r9")
+__jited(" callq")
+__jited(" popq %r9")
+__naked void private_stack_callback(void)
+{
+ asm volatile (" \
+ r1 = 1; \
+ r2 = %[loop_callback]; \
+ r3 = 0; \
+ r4 = 0; \
+ call %[bpf_loop]; \
+ r0 = 0; \
+ exit; \
+" :
+ : __imm_ptr(loop_callback),
+ __imm(bpf_loop)
+ : __clobber_common);
+}
+
+SEC("fentry/bpf_fentry_test9")
+__description("Private stack, exception in main prog")
+__success __retval(0)
+__arch_x86_64
+__jited(" pushq %r9")
+__jited(" callq")
+__jited(" popq %r9")
+int private_stack_exception_main_prog(void)
+{
+ asm volatile (" \
+ r1 = 42; \
+ *(u64 *)(r10 - 512) = r1; \
+" ::: __clobber_common);
+
+ bpf_throw(0);
+ return 0;
+}
+
+__used static int subprog_exception(void)
+{
+ bpf_throw(0);
+ return 0;
+}
+
+SEC("fentry/bpf_fentry_test9")
+__description("Private stack, exception in subprog")
+__success __retval(0)
+__arch_x86_64
+__jited(" movq %rdi, -0x200(%r9)")
+__jited(" pushq %r9")
+__jited(" callq")
+__jited(" popq %r9")
+int private_stack_exception_sub_prog(void)
+{
+ asm volatile (" \
+ r1 = 42; \
+ *(u64 *)(r10 - 512) = r1; \
+ call subprog_exception; \
+" ::: __clobber_common);
+
+ return 0;
+}
+
+int glob;
+__noinline static void subprog2(int *val)
+{
+ glob += val[0] * 2;
+}
+
+__noinline static void subprog1(int *val)
+{
+ int tmp[64] = {};
+
+ tmp[0] = *val;
+ subprog2(tmp);
+}
+
+__noinline static int timer_cb1(void *map, int *key, struct bpf_timer *timer)
+{
+ subprog1(key);
+ return 0;
+}
+
+__noinline static int timer_cb2(void *map, int *key, struct bpf_timer *timer)
+{
+ return 0;
+}
+
+SEC("fentry/bpf_fentry_test9")
+__description("Private stack, async callback, not nested")
+__success __retval(0)
+__arch_x86_64
+__jited(" movabsq $0x{{.*}}, %r9")
+int private_stack_async_callback_1(void)
+{
+ struct bpf_timer *arr_timer;
+ int array_key = 0;
+
+ arr_timer = bpf_map_lookup_elem(&array, &array_key);
+ if (!arr_timer)
+ return 0;
+
+ bpf_timer_init(arr_timer, &array, 1);
+ bpf_timer_set_callback(arr_timer, timer_cb2);
+ bpf_timer_start(arr_timer, 0, 0);
+ subprog1(&array_key);
+ return 0;
+}
+
+SEC("fentry/bpf_fentry_test9")
+__description("Private stack, async callback, potential nesting")
+__success __retval(0)
+__arch_x86_64
+__jited(" subq $0x100, %rsp")
+int private_stack_async_callback_2(void)
+{
+ struct bpf_timer *arr_timer;
+ int array_key = 0;
+
+ arr_timer = bpf_map_lookup_elem(&array, &array_key);
+ if (!arr_timer)
+ return 0;
+
+ bpf_timer_init(arr_timer, &array, 1);
+ bpf_timer_set_callback(arr_timer, timer_cb1);
+ bpf_timer_start(arr_timer, 0, 0);
+ subprog1(&array_key);
+ return 0;
+}
+
+#else
+
+SEC("kprobe")
+__description("private stack is not supported, use a dummy test")
+__success
+int dummy_test(void)
+{
+ return 0;
+}
+
+#endif
+
+char _license[] SEC("license") = "GPL";
--
2.43.5
