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etsalAlexei Starovoitov
etsal
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Alexei Starovoitov
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selftests/bpf: add selftests for bpf_arena_reserve_pages
Add selftests for the new bpf_arena_reserve_pages kfunc. Acked-by: Yonghong Song <[email protected]> Signed-off-by: Emil Tsalapatis <[email protected]> Acked-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
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‎tools/testing/selftests/bpf/bpf_arena_common.h

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@@ -46,8 +46,11 @@
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void __arena* bpf_arena_alloc_pages(void *map, void __arena *addr, __u32 page_cnt,
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int node_id, __u64 flags) __ksym __weak;
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int bpf_arena_reserve_pages(void *map, void __arena *addr, __u32 page_cnt) __ksym __weak;
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void bpf_arena_free_pages(void *map, void __arena *ptr, __u32 page_cnt) __ksym __weak;
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#define arena_base(map) ((void __arena *)((struct bpf_arena *)(map))->user_vm_start)
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#else /* when compiled as user space code */
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#define __arena

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

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@@ -3,6 +3,7 @@
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#define BPF_NO_KFUNC_PROTOTYPES
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#include <vmlinux.h>
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#include <errno.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include "bpf_misc.h"
@@ -114,6 +115,111 @@ int basic_alloc3(void *ctx)
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return 0;
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}
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SEC("syscall")
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__success __retval(0)
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int basic_reserve1(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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char __arena *page;
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int ret;
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page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
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if (!page)
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return 1;
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page += __PAGE_SIZE;
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/* Reserve the second page */
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ret = bpf_arena_reserve_pages(&arena, page, 1);
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if (ret)
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return 2;
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/* Try to explicitly allocate the reserved page. */
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page = bpf_arena_alloc_pages(&arena, page, 1, NUMA_NO_NODE, 0);
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if (page)
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return 3;
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/* Try to implicitly allocate the page (since there's only 2 of them). */
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page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
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if (page)
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return 4;
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#endif
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return 0;
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}
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SEC("syscall")
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__success __retval(0)
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int basic_reserve2(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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char __arena *page;
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int ret;
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page = arena_base(&arena);
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ret = bpf_arena_reserve_pages(&arena, page, 1);
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if (ret)
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return 1;
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page = bpf_arena_alloc_pages(&arena, page, 1, NUMA_NO_NODE, 0);
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if ((u64)page)
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return 2;
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#endif
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return 0;
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}
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/* Reserve the same page twice, should return -EBUSY. */
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SEC("syscall")
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__success __retval(0)
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int reserve_twice(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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char __arena *page;
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int ret;
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page = arena_base(&arena);
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ret = bpf_arena_reserve_pages(&arena, page, 1);
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if (ret)
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return 1;
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ret = bpf_arena_reserve_pages(&arena, page, 1);
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if (ret != -EBUSY)
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return 2;
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#endif
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return 0;
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}
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/* Try to reserve past the end of the arena. */
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SEC("syscall")
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__success __retval(0)
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int reserve_invalid_region(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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char __arena *page;
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int ret;
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/* Try a NULL pointer. */
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ret = bpf_arena_reserve_pages(&arena, NULL, 3);
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if (ret != -EINVAL)
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return 1;
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page = arena_base(&arena);
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ret = bpf_arena_reserve_pages(&arena, page, 3);
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if (ret != -EINVAL)
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return 2;
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ret = bpf_arena_reserve_pages(&arena, page, 4096);
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if (ret != -EINVAL)
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return 3;
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ret = bpf_arena_reserve_pages(&arena, page, (1ULL << 32) - 1);
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if (ret != -EINVAL)
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return 4;
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#endif
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return 0;
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}
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SEC("iter.s/bpf_map")
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__success __log_level(2)
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int iter_maps1(struct bpf_iter__bpf_map *ctx)

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

Lines changed: 98 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -67,6 +67,104 @@ int big_alloc1(void *ctx)
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return 0;
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}
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/* Try to access a reserved page. Behavior should be identical with accessing unallocated pages. */
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SEC("syscall")
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__success __retval(0)
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int access_reserved(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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volatile char __arena *page;
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char __arena *base;
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const size_t len = 4;
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int ret, i;
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/* Get a separate region of the arena. */
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page = base = arena_base(&arena) + 16384 * PAGE_SIZE;
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ret = bpf_arena_reserve_pages(&arena, base, len);
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if (ret)
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return 1;
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/* Try to dirty reserved memory. */
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for (i = 0; i < len && can_loop; i++)
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*page = 0x5a;
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for (i = 0; i < len && can_loop; i++) {
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page = (volatile char __arena *)(base + i * PAGE_SIZE);
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/*
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* Error out in case either the write went through,
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* or the address has random garbage.
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*/
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if (*page == 0x5a)
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return 2 + 2 * i;
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if (*page)
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return 2 + 2 * i + 1;
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}
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#endif
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return 0;
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}
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/* Try to allocate a region overlapping with a reservation. */
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SEC("syscall")
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__success __retval(0)
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int request_partially_reserved(void *ctx)
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{
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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volatile char __arena *page;
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char __arena *base;
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int ret;
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/* Add an arbitrary page offset. */
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page = base = arena_base(&arena) + 4096 * __PAGE_SIZE;
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ret = bpf_arena_reserve_pages(&arena, base + 3 * __PAGE_SIZE, 4);
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if (ret)
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return 1;
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page = bpf_arena_alloc_pages(&arena, base, 5, NUMA_NO_NODE, 0);
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if ((u64)page != 0ULL)
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return 2;
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#endif
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return 0;
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}
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SEC("syscall")
134+
__success __retval(0)
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int free_reserved(void *ctx)
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{
137+
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
138+
char __arena *addr;
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char __arena *page;
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int ret;
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/* Add an arbitrary page offset. */
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addr = arena_base(&arena) + 32768 * __PAGE_SIZE;
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page = bpf_arena_alloc_pages(&arena, addr, 2, NUMA_NO_NODE, 0);
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if (!page)
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return 1;
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149+
ret = bpf_arena_reserve_pages(&arena, addr + 2 * __PAGE_SIZE, 2);
150+
if (ret)
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return 2;
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/*
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* Reserved and allocated pages should be interchangeable for
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* bpf_arena_free_pages(). Free a reserved and an allocated
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* page with a single call.
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*/
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bpf_arena_free_pages(&arena, addr + __PAGE_SIZE , 2);
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/* The free call above should have succeeded, so this allocation should too. */
161+
page = bpf_arena_alloc_pages(&arena, addr + __PAGE_SIZE, 2, NUMA_NO_NODE, 0);
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if (!page)
163+
return 3;
164+
#endif
165+
return 0;
166+
}
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#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
71169
#define PAGE_CNT 100
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__u8 __arena * __arena page[PAGE_CNT]; /* occupies the first page */

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