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authorUros Bizjak <ubizjak@gmail.com>2024-08-11 18:13:33 +0200
committerAlexei Starovoitov <ast@kernel.org>2024-08-22 08:01:50 -0700
commit6d641ca50d7ec7d5e4e889c3f8ea22afebc2a403 (patch)
treeafcab8075abea35ce486c5094e647f99270b5b05
parent5148f19ac4bdf66b5bf5736e8e9d1df323c0dcb4 (diff)
bpf: Fix percpu address space issues
In arraymap.c: In bpf_array_map_seq_start() and bpf_array_map_seq_next() cast return values from the __percpu address space to the generic address space via uintptr_t [1]. Correct the declaration of pptr pointer in __bpf_array_map_seq_show() to void __percpu * and cast the value from the generic address space to the __percpu address space via uintptr_t [1]. In hashtab.c: Assign the return value from bpf_mem_cache_alloc() to void pointer and cast the value to void __percpu ** (void pointer to percpu void pointer) before dereferencing. In memalloc.c: Explicitly declare __percpu variables. Cast obj to void __percpu **. In helpers.c: Cast ptr in BPF_CALL_1 and BPF_CALL_2 from generic address space to __percpu address space via const uintptr_t [1]. Found by GCC's named address space checks. There were no changes in the resulting object files. [1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240811161414.56744-1-ubizjak@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--kernel/bpf/arraymap.c8
-rw-r--r--kernel/bpf/hashtab.c9
-rw-r--r--kernel/bpf/helpers.c4
-rw-r--r--kernel/bpf/memalloc.c12
4 files changed, 17 insertions, 16 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 188e3c2effb2..a43e62e2a8bb 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -600,7 +600,7 @@ static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
array = container_of(map, struct bpf_array, map);
index = info->index & array->index_mask;
if (info->percpu_value_buf)
- return array->pptrs[index];
+ return (void *)(uintptr_t)array->pptrs[index];
return array_map_elem_ptr(array, index);
}
@@ -619,7 +619,7 @@ static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
array = container_of(map, struct bpf_array, map);
index = info->index & array->index_mask;
if (info->percpu_value_buf)
- return array->pptrs[index];
+ return (void *)(uintptr_t)array->pptrs[index];
return array_map_elem_ptr(array, index);
}
@@ -632,7 +632,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
struct bpf_iter_meta meta;
struct bpf_prog *prog;
int off = 0, cpu = 0;
- void __percpu **pptr;
+ void __percpu *pptr;
u32 size;
meta.seq = seq;
@@ -648,7 +648,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
if (!info->percpu_value_buf) {
ctx.value = v;
} else {
- pptr = v;
+ pptr = (void __percpu *)(uintptr_t)v;
size = array->elem_size;
for_each_possible_cpu(cpu) {
copy_map_value_long(map, info->percpu_value_buf + off,
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index be1f64c20125..45c7195b65ba 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1049,14 +1049,15 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
pptr = htab_elem_get_ptr(l_new, key_size);
} else {
/* alloc_percpu zero-fills */
- pptr = bpf_mem_cache_alloc(&htab->pcpu_ma);
- if (!pptr) {
+ void *ptr = bpf_mem_cache_alloc(&htab->pcpu_ma);
+
+ if (!ptr) {
bpf_mem_cache_free(&htab->ma, l_new);
l_new = ERR_PTR(-ENOMEM);
goto dec_count;
}
- l_new->ptr_to_pptr = pptr;
- pptr = *(void **)pptr;
+ l_new->ptr_to_pptr = ptr;
+ pptr = *(void __percpu **)ptr;
}
pcpu_init_value(htab, pptr, value, onallcpus);
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 12e3aa40b180..ccca6fe0367c 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -715,7 +715,7 @@ BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
if (cpu >= nr_cpu_ids)
return (unsigned long)NULL;
- return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
+ return (unsigned long)per_cpu_ptr((const void __percpu *)(const uintptr_t)ptr, cpu);
}
const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
@@ -728,7 +728,7 @@ const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
{
- return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
+ return (unsigned long)this_cpu_ptr((const void __percpu *)(const uintptr_t)percpu_ptr);
}
const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index dec892ded031..b3858a76e0b3 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -138,8 +138,8 @@ static struct llist_node notrace *__llist_del_first(struct llist_head *head)
static void *__alloc(struct bpf_mem_cache *c, int node, gfp_t flags)
{
if (c->percpu_size) {
- void **obj = kmalloc_node(c->percpu_size, flags, node);
- void *pptr = __alloc_percpu_gfp(c->unit_size, 8, flags);
+ void __percpu **obj = kmalloc_node(c->percpu_size, flags, node);
+ void __percpu *pptr = __alloc_percpu_gfp(c->unit_size, 8, flags);
if (!obj || !pptr) {
free_percpu(pptr);
@@ -253,7 +253,7 @@ static void alloc_bulk(struct bpf_mem_cache *c, int cnt, int node, bool atomic)
static void free_one(void *obj, bool percpu)
{
if (percpu) {
- free_percpu(((void **)obj)[1]);
+ free_percpu(((void __percpu **)obj)[1]);
kfree(obj);
return;
}
@@ -509,8 +509,8 @@ static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu)
*/
int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
{
- struct bpf_mem_caches *cc, __percpu *pcc;
- struct bpf_mem_cache *c, __percpu *pc;
+ struct bpf_mem_caches *cc; struct bpf_mem_caches __percpu *pcc;
+ struct bpf_mem_cache *c; struct bpf_mem_cache __percpu *pc;
struct obj_cgroup *objcg = NULL;
int cpu, i, unit_size, percpu_size = 0;
@@ -591,7 +591,7 @@ int bpf_mem_alloc_percpu_init(struct bpf_mem_alloc *ma, struct obj_cgroup *objcg
int bpf_mem_alloc_percpu_unit_init(struct bpf_mem_alloc *ma, int size)
{
- struct bpf_mem_caches *cc, __percpu *pcc;
+ struct bpf_mem_caches *cc; struct bpf_mem_caches __percpu *pcc;
int cpu, i, unit_size, percpu_size;
struct obj_cgroup *objcg;
struct bpf_mem_cache *c;