| Message ID | 20240209040608.98927-13-alexei.starovoitov@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | bpf: Introduce BPF arena. | expand |
On Thu, 2024-02-08 at 20:06 -0800, Alexei Starovoitov wrote: [...] > @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size) > int err; > size_t mmap_old_sz, mmap_new_sz; > > - mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > - mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries); > + mmap_old_sz = bpf_map_mmap_sz(map); > + mmap_new_sz = __bpf_map_mmap_sz(size, map->def.max_entries); > err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz); > if (err) { > pr_warn("map '%s': failed to resize memory-mapped region: %d\n", I think that as is bpf_map__set_value_size() won't work for arenas. The bpf_map_mmap_resize() does the following: static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz) { ... mmaped = mmap(NULL, new_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); ... memcpy(mmaped, map->mmaped, min(old_sz, new_sz)); munmap(map->mmaped, old_sz); map->mmaped = mmaped; ... } Which does not seem to tie the new mapping to arena, or am I missing something?
On Fri, Feb 9, 2024 at 11:17 PM Kumar Kartikeya Dwivedi <memxor@gmail.com> wrote: > > On Fri, 9 Feb 2024 at 05:07, Alexei Starovoitov > <alexei.starovoitov@gmail.com> wrote: > > > > From: Alexei Starovoitov <ast@kernel.org> > > > > mmap() bpf_arena right after creation, since the kernel needs to > > remember the address returned from mmap. This is user_vm_start. > > LLVM will generate bpf_arena_cast_user() instructions where > > necessary and JIT will add upper 32-bit of user_vm_start > > to such pointers. > > > > Fix up bpf_map_mmap_sz() to compute mmap size as > > map->value_size * map->max_entries for arrays and > > PAGE_SIZE * map->max_entries for arena. > > > > Don't set BTF at arena creation time, since it doesn't support it. > > > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > > --- > > tools/lib/bpf/libbpf.c | 43 ++++++++++++++++++++++++++++++----- > > tools/lib/bpf/libbpf_probes.c | 7 ++++++ > > 2 files changed, 44 insertions(+), 6 deletions(-) > > > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 01f407591a92..4880d623098d 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -185,6 +185,7 @@ static const char * const map_type_name[] = { > > [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", > > [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", > > [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", > > + [BPF_MAP_TYPE_ARENA] = "arena", > > }; > > > > static const char * const prog_type_name[] = { > > @@ -1577,7 +1578,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) > > return map; > > } > > > > -static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > +static size_t __bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > { > > const long page_sz = sysconf(_SC_PAGE_SIZE); > > size_t map_sz; > > @@ -1587,6 +1588,20 @@ static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > return map_sz; > > } > > > > +static size_t bpf_map_mmap_sz(const struct bpf_map *map) > > +{ > > + const long page_sz = sysconf(_SC_PAGE_SIZE); > > + > > + switch (map->def.type) { > > + case BPF_MAP_TYPE_ARRAY: > > + return __bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > + case BPF_MAP_TYPE_ARENA: > > + return page_sz * map->def.max_entries; > > + default: > > + return 0; /* not supported */ > > + } > > +} > > + > > static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz) > > { > > void *mmaped; > > @@ -1740,7 +1755,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, > > pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", > > map->name, map->sec_idx, map->sec_offset, def->map_flags); > > > > - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > + mmap_sz = bpf_map_mmap_sz(map); > > map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, > > MAP_SHARED | MAP_ANONYMOUS, -1, 0); > > if (map->mmaped == MAP_FAILED) { > > @@ -4852,6 +4867,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > > case BPF_MAP_TYPE_SOCKHASH: > > case BPF_MAP_TYPE_QUEUE: > > case BPF_MAP_TYPE_STACK: > > + case BPF_MAP_TYPE_ARENA: > > create_attr.btf_fd = 0; > > create_attr.btf_key_type_id = 0; > > create_attr.btf_value_type_id = 0; > > @@ -4908,6 +4924,21 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > > if (map->fd == map_fd) > > return 0; > > > > + if (def->type == BPF_MAP_TYPE_ARENA) { > > + map->mmaped = mmap((void *)map->map_extra, bpf_map_mmap_sz(map), > > + PROT_READ | PROT_WRITE, > > + map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED, > > + map_fd, 0); > > + if (map->mmaped == MAP_FAILED) { > > + err = -errno; > > + map->mmaped = NULL; > > + close(map_fd); > > + pr_warn("map '%s': failed to mmap bpf_arena: %d\n", > > + bpf_map__name(map), err); > > + return err; > > + } > > + } > > + > > Would it be possible to introduce a public API accessor for getting > the value of map->mmaped? That would be bpf_map__initial_value(), no? > Otherwise one would have to parse through /proc/self/maps in case > map_extra is 0. > > The use case is to be able to use the arena as a backing store for > userspace malloc arenas, so that > we can pass through malloc/mallocx calls (or class specific operator > new) directly to malloc arena using the BPF arena. > In such a case a lot of the burden of converting existing data > structures or code can be avoided by making much of the process > transparent. > Userspace malloced objects can also be easily shared to BPF progs as a > pool through bpf_ma style per-CPU allocator. > > > [...]
On Mon, Feb 12, 2024 at 10:12 AM Eduard Zingerman <eddyz87@gmail.com> wrote: > > On Thu, 2024-02-08 at 20:06 -0800, Alexei Starovoitov wrote: > [...] > > > @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size) > > int err; > > size_t mmap_old_sz, mmap_new_sz; > > > > - mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > - mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries); > > + mmap_old_sz = bpf_map_mmap_sz(map); > > + mmap_new_sz = __bpf_map_mmap_sz(size, map->def.max_entries); > > err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz); > > if (err) { > > pr_warn("map '%s': failed to resize memory-mapped region: %d\n", > > I think that as is bpf_map__set_value_size() won't work for arenas. It doesn't and doesn't work for ringbuf either. I guess we can add a filter by map type, but I'm not sure how big this can of worms (extra checks) will be. There are probably many libbpf apis that can be misused. Like bpf_map__set_type()
On Mon, 2024-02-12 at 12:14 -0800, Alexei Starovoitov wrote: [...] > It doesn't and doesn't work for ringbuf either. > I guess we can add a filter by map type, but I'm not sure > how big this can of worms (extra checks) will be. > There are probably many libbpf apis that can be misused. > Like bpf_map__set_type() Right, probably such extra checks should be a subject of a different patch-set (if any).
On Thu, Feb 8, 2024 at 8:07 PM Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote: > > From: Alexei Starovoitov <ast@kernel.org> > > mmap() bpf_arena right after creation, since the kernel needs to > remember the address returned from mmap. This is user_vm_start. > LLVM will generate bpf_arena_cast_user() instructions where > necessary and JIT will add upper 32-bit of user_vm_start > to such pointers. > > Fix up bpf_map_mmap_sz() to compute mmap size as > map->value_size * map->max_entries for arrays and > PAGE_SIZE * map->max_entries for arena. > > Don't set BTF at arena creation time, since it doesn't support it. > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > --- > tools/lib/bpf/libbpf.c | 43 ++++++++++++++++++++++++++++++----- > tools/lib/bpf/libbpf_probes.c | 7 ++++++ > 2 files changed, 44 insertions(+), 6 deletions(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 01f407591a92..4880d623098d 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -185,6 +185,7 @@ static const char * const map_type_name[] = { > [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", > [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", > [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", > + [BPF_MAP_TYPE_ARENA] = "arena", > }; > > static const char * const prog_type_name[] = { > @@ -1577,7 +1578,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) > return map; > } > > -static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > +static size_t __bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) please rename this to array_map_mmap_sz, underscores are not very meaningful > { > const long page_sz = sysconf(_SC_PAGE_SIZE); > size_t map_sz; > @@ -1587,6 +1588,20 @@ static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > return map_sz; > } > > +static size_t bpf_map_mmap_sz(const struct bpf_map *map) > +{ > + const long page_sz = sysconf(_SC_PAGE_SIZE); > + > + switch (map->def.type) { > + case BPF_MAP_TYPE_ARRAY: > + return __bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > + case BPF_MAP_TYPE_ARENA: > + return page_sz * map->def.max_entries; > + default: > + return 0; /* not supported */ > + } > +} > + > static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz) > { > void *mmaped; > @@ -1740,7 +1755,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, > pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", > map->name, map->sec_idx, map->sec_offset, def->map_flags); > > - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > + mmap_sz = bpf_map_mmap_sz(map); > map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, > MAP_SHARED | MAP_ANONYMOUS, -1, 0); > if (map->mmaped == MAP_FAILED) { > @@ -4852,6 +4867,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > case BPF_MAP_TYPE_SOCKHASH: > case BPF_MAP_TYPE_QUEUE: > case BPF_MAP_TYPE_STACK: > + case BPF_MAP_TYPE_ARENA: > create_attr.btf_fd = 0; > create_attr.btf_key_type_id = 0; > create_attr.btf_value_type_id = 0; > @@ -4908,6 +4924,21 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > if (map->fd == map_fd) > return 0; > > + if (def->type == BPF_MAP_TYPE_ARENA) { > + map->mmaped = mmap((void *)map->map_extra, bpf_map_mmap_sz(map), > + PROT_READ | PROT_WRITE, > + map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED, > + map_fd, 0); > + if (map->mmaped == MAP_FAILED) { > + err = -errno; > + map->mmaped = NULL; > + close(map_fd); > + pr_warn("map '%s': failed to mmap bpf_arena: %d\n", > + bpf_map__name(map), err); seems like we just use `map->name` directly elsewhere in this function, let's keep it consistent > + return err; > + } > + } > + > /* Keep placeholder FD value but now point it to the BPF map object. > * This way everything that relied on this map's FD (e.g., relocated > * ldimm64 instructions) will stay valid and won't need adjustments. > @@ -8582,7 +8613,7 @@ static void bpf_map__destroy(struct bpf_map *map) > if (map->mmaped) { > size_t mmap_sz; > > - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > + mmap_sz = bpf_map_mmap_sz(map); > munmap(map->mmaped, mmap_sz); > map->mmaped = NULL; > } > @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size) > int err; > size_t mmap_old_sz, mmap_new_sz; > this logic assumes ARRAY (which are the only ones so far that could have `map->mapped != NULL`, so I think we should error out for ARENA maps here, instead of silently doing the wrong thing? if (map->type != BPF_MAP_TYPE_ARRAY) return -EOPNOTSUPP; should do > - mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > - mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries); > + mmap_old_sz = bpf_map_mmap_sz(map); > + mmap_new_sz = __bpf_map_mmap_sz(size, map->def.max_entries); > err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz); > if (err) { > pr_warn("map '%s': failed to resize memory-mapped region: %d\n", > @@ -13356,7 +13387,7 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s) > > for (i = 0; i < s->map_cnt; i++) { > struct bpf_map *map = *s->maps[i].map; > - size_t mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > + size_t mmap_sz = bpf_map_mmap_sz(map); > int prot, map_fd = map->fd; > void **mmaped = s->maps[i].mmaped; > > diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c > index ee9b1dbea9eb..302188122439 100644 > --- a/tools/lib/bpf/libbpf_probes.c > +++ b/tools/lib/bpf/libbpf_probes.c > @@ -338,6 +338,13 @@ static int probe_map_create(enum bpf_map_type map_type) > key_size = 0; > max_entries = 1; > break; > + case BPF_MAP_TYPE_ARENA: > + key_size = 0; > + value_size = 0; > + max_entries = 1; /* one page */ > + opts.map_extra = 0; /* can mmap() at any address */ > + opts.map_flags = BPF_F_MMAPABLE; > + break; > case BPF_MAP_TYPE_HASH: > case BPF_MAP_TYPE_ARRAY: > case BPF_MAP_TYPE_PROG_ARRAY: > -- > 2.34.1 >
On Tue, Feb 13, 2024 at 3:15 PM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Thu, Feb 8, 2024 at 8:07 PM Alexei Starovoitov > <alexei.starovoitov@gmail.com> wrote: > > > > From: Alexei Starovoitov <ast@kernel.org> > > > > mmap() bpf_arena right after creation, since the kernel needs to > > remember the address returned from mmap. This is user_vm_start. > > LLVM will generate bpf_arena_cast_user() instructions where > > necessary and JIT will add upper 32-bit of user_vm_start > > to such pointers. > > > > Fix up bpf_map_mmap_sz() to compute mmap size as > > map->value_size * map->max_entries for arrays and > > PAGE_SIZE * map->max_entries for arena. > > > > Don't set BTF at arena creation time, since it doesn't support it. > > > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > > --- > > tools/lib/bpf/libbpf.c | 43 ++++++++++++++++++++++++++++++----- > > tools/lib/bpf/libbpf_probes.c | 7 ++++++ > > 2 files changed, 44 insertions(+), 6 deletions(-) > > > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 01f407591a92..4880d623098d 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -185,6 +185,7 @@ static const char * const map_type_name[] = { > > [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", > > [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", > > [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", > > + [BPF_MAP_TYPE_ARENA] = "arena", > > }; > > > > static const char * const prog_type_name[] = { > > @@ -1577,7 +1578,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) > > return map; > > } > > > > -static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > +static size_t __bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > please rename this to array_map_mmap_sz, underscores are not very meaningful makes sense. > > { > > const long page_sz = sysconf(_SC_PAGE_SIZE); > > size_t map_sz; > > @@ -1587,6 +1588,20 @@ static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) > > return map_sz; > > } > > > > +static size_t bpf_map_mmap_sz(const struct bpf_map *map) > > +{ > > + const long page_sz = sysconf(_SC_PAGE_SIZE); > > + > > + switch (map->def.type) { > > + case BPF_MAP_TYPE_ARRAY: > > + return __bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > + case BPF_MAP_TYPE_ARENA: > > + return page_sz * map->def.max_entries; > > + default: > > + return 0; /* not supported */ > > + } > > +} > > + > > static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz) > > { > > void *mmaped; > > @@ -1740,7 +1755,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, > > pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", > > map->name, map->sec_idx, map->sec_offset, def->map_flags); > > > > - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > + mmap_sz = bpf_map_mmap_sz(map); > > map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, > > MAP_SHARED | MAP_ANONYMOUS, -1, 0); > > if (map->mmaped == MAP_FAILED) { > > @@ -4852,6 +4867,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > > case BPF_MAP_TYPE_SOCKHASH: > > case BPF_MAP_TYPE_QUEUE: > > case BPF_MAP_TYPE_STACK: > > + case BPF_MAP_TYPE_ARENA: > > create_attr.btf_fd = 0; > > create_attr.btf_key_type_id = 0; > > create_attr.btf_value_type_id = 0; > > @@ -4908,6 +4924,21 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b > > if (map->fd == map_fd) > > return 0; > > > > + if (def->type == BPF_MAP_TYPE_ARENA) { > > + map->mmaped = mmap((void *)map->map_extra, bpf_map_mmap_sz(map), > > + PROT_READ | PROT_WRITE, > > + map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED, > > + map_fd, 0); > > + if (map->mmaped == MAP_FAILED) { > > + err = -errno; > > + map->mmaped = NULL; > > + close(map_fd); > > + pr_warn("map '%s': failed to mmap bpf_arena: %d\n", > > + bpf_map__name(map), err); > > seems like we just use `map->name` directly elsewhere in this > function, let's keep it consistent that was to match the next patch, since arena is using real_name. map->name is also correct and will have the same name here. The next patch will have two arena maps, but one will never be passed into this function to create a real kernel map. So I can use map->name here, but bpf_map__name() is a bit more correct. > > + return err; > > + } > > + } > > + > > /* Keep placeholder FD value but now point it to the BPF map object. > > * This way everything that relied on this map's FD (e.g., relocated > > * ldimm64 instructions) will stay valid and won't need adjustments. > > @@ -8582,7 +8613,7 @@ static void bpf_map__destroy(struct bpf_map *map) > > if (map->mmaped) { > > size_t mmap_sz; > > > > - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); > > + mmap_sz = bpf_map_mmap_sz(map); > > munmap(map->mmaped, mmap_sz); > > map->mmaped = NULL; > > } > > @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size) > > int err; > > size_t mmap_old_sz, mmap_new_sz; > > > > this logic assumes ARRAY (which are the only ones so far that could > have `map->mapped != NULL`, so I think we should error out for ARENA > maps here, instead of silently doing the wrong thing? > > if (map->type != BPF_MAP_TYPE_ARRAY) > return -EOPNOTSUPP; > > should do Good point. Will do.
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 01f407591a92..4880d623098d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -185,6 +185,7 @@ static const char * const map_type_name[] = { [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", [BPF_MAP_TYPE_CGRP_STORAGE] = "cgrp_storage", + [BPF_MAP_TYPE_ARENA] = "arena", }; static const char * const prog_type_name[] = { @@ -1577,7 +1578,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) return map; } -static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) +static size_t __bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) { const long page_sz = sysconf(_SC_PAGE_SIZE); size_t map_sz; @@ -1587,6 +1588,20 @@ static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries) return map_sz; } +static size_t bpf_map_mmap_sz(const struct bpf_map *map) +{ + const long page_sz = sysconf(_SC_PAGE_SIZE); + + switch (map->def.type) { + case BPF_MAP_TYPE_ARRAY: + return __bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); + case BPF_MAP_TYPE_ARENA: + return page_sz * map->def.max_entries; + default: + return 0; /* not supported */ + } +} + static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz) { void *mmaped; @@ -1740,7 +1755,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n", map->name, map->sec_idx, map->sec_offset, def->map_flags); - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); + mmap_sz = bpf_map_mmap_sz(map); map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); if (map->mmaped == MAP_FAILED) { @@ -4852,6 +4867,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b case BPF_MAP_TYPE_SOCKHASH: case BPF_MAP_TYPE_QUEUE: case BPF_MAP_TYPE_STACK: + case BPF_MAP_TYPE_ARENA: create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; @@ -4908,6 +4924,21 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b if (map->fd == map_fd) return 0; + if (def->type == BPF_MAP_TYPE_ARENA) { + map->mmaped = mmap((void *)map->map_extra, bpf_map_mmap_sz(map), + PROT_READ | PROT_WRITE, + map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED, + map_fd, 0); + if (map->mmaped == MAP_FAILED) { + err = -errno; + map->mmaped = NULL; + close(map_fd); + pr_warn("map '%s': failed to mmap bpf_arena: %d\n", + bpf_map__name(map), err); + return err; + } + } + /* Keep placeholder FD value but now point it to the BPF map object. * This way everything that relied on this map's FD (e.g., relocated * ldimm64 instructions) will stay valid and won't need adjustments. @@ -8582,7 +8613,7 @@ static void bpf_map__destroy(struct bpf_map *map) if (map->mmaped) { size_t mmap_sz; - mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); + mmap_sz = bpf_map_mmap_sz(map); munmap(map->mmaped, mmap_sz); map->mmaped = NULL; } @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size) int err; size_t mmap_old_sz, mmap_new_sz; - mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); - mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries); + mmap_old_sz = bpf_map_mmap_sz(map); + mmap_new_sz = __bpf_map_mmap_sz(size, map->def.max_entries); err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz); if (err) { pr_warn("map '%s': failed to resize memory-mapped region: %d\n", @@ -13356,7 +13387,7 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s) for (i = 0; i < s->map_cnt; i++) { struct bpf_map *map = *s->maps[i].map; - size_t mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries); + size_t mmap_sz = bpf_map_mmap_sz(map); int prot, map_fd = map->fd; void **mmaped = s->maps[i].mmaped; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index ee9b1dbea9eb..302188122439 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -338,6 +338,13 @@ static int probe_map_create(enum bpf_map_type map_type) key_size = 0; max_entries = 1; break; + case BPF_MAP_TYPE_ARENA: + key_size = 0; + value_size = 0; + max_entries = 1; /* one page */ + opts.map_extra = 0; /* can mmap() at any address */ + opts.map_flags = BPF_F_MMAPABLE; + break; case BPF_MAP_TYPE_HASH: case BPF_MAP_TYPE_ARRAY: case BPF_MAP_TYPE_PROG_ARRAY: