From: Ilya Leoshkevich iii@linux.ibm.com
[ Upstream commit 166f11d11f6f70439830d09bfa5552ec1b368494 ]
A BPF program may consist of 1m instructions, which means JIT instruction-address mapping can be as large as 4m. s390 has FORCE_MAX_ZONEORDER=9 (for memory hotplug reasons), which means maximum kmalloc size is 1m. This makes it impossible to JIT programs with more than 256k instructions.
Fix by using kvcalloc, which falls back to vmalloc for larger allocations. An alternative would be to use a radix tree, but that is not supported by bpf_prog_fill_jited_linfo.
Signed-off-by: Ilya Leoshkevich iii@linux.ibm.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/20191107141838.92202-1-iii@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/net/bpf_jit_comp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index ce88211b9c6c..c8c16b5eed6b 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -23,6 +23,7 @@ #include <linux/filter.h> #include <linux/init.h> #include <linux/bpf.h> +#include <linux/mm.h> #include <asm/cacheflush.h> #include <asm/dis.h> #include <asm/facility.h> @@ -1369,7 +1370,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) }
memset(&jit, 0, sizeof(jit)); - jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL); + jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL); if (jit.addrs == NULL) { fp = orig_fp; goto out; @@ -1422,7 +1423,7 @@ skip_init_ctx: if (!fp->is_func || extra_pass) { bpf_prog_fill_jited_linfo(fp, jit.addrs + 1); free_addrs: - kfree(jit.addrs); + kvfree(jit.addrs); kfree(jit_data); fp->aux->jit_data = NULL; }