s390/bpf: Use kvcalloc for addrs array

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 <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
penberg · Nov 7, 2019 · 166f11d · 166f11d
1 parent 7e22077
commit 166f11d
Showing 1 changed file with 3 additions and 2 deletions.
diff --git 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 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	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;
 	}