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-rw-r--r--include/linux/filter.h2
-rw-r--r--kernel/bpf/core.c21
-rw-r--r--net/core/sysctl_net_core.c20
3 files changed, 33 insertions, 10 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 795ff0b869bb..a8b9d90a8042 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -861,7 +861,7 @@ bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
extern int bpf_jit_enable;
extern int bpf_jit_harden;
extern int bpf_jit_kallsyms;
-extern int bpf_jit_limit;
+extern long bpf_jit_limit;
typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index b1a3545d0ec8..b2890c268cb3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -365,13 +365,11 @@ void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
}
#ifdef CONFIG_BPF_JIT
-# define BPF_JIT_LIMIT_DEFAULT (PAGE_SIZE * 40000)
-
/* All BPF JIT sysctl knobs here. */
int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
int bpf_jit_harden __read_mostly;
int bpf_jit_kallsyms __read_mostly;
-int bpf_jit_limit __read_mostly = BPF_JIT_LIMIT_DEFAULT;
+long bpf_jit_limit __read_mostly;
static __always_inline void
bpf_get_prog_addr_region(const struct bpf_prog *prog,
@@ -580,16 +578,27 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
static atomic_long_t bpf_jit_current;
+/* Can be overridden by an arch's JIT compiler if it has a custom,
+ * dedicated BPF backend memory area, or if neither of the two
+ * below apply.
+ */
+u64 __weak bpf_jit_alloc_exec_limit(void)
+{
#if defined(MODULES_VADDR)
+ return MODULES_END - MODULES_VADDR;
+#else
+ return VMALLOC_END - VMALLOC_START;
+#endif
+}
+
static int __init bpf_jit_charge_init(void)
{
/* Only used as heuristic here to derive limit. */
- bpf_jit_limit = min_t(u64, round_up((MODULES_END - MODULES_VADDR) >> 2,
- PAGE_SIZE), INT_MAX);
+ bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
+ PAGE_SIZE), LONG_MAX);
return 0;
}
pure_initcall(bpf_jit_charge_init);
-#endif
static int bpf_jit_charge_modmem(u32 pages)
{
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 37b4667128a3..d67ec17f2cc8 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -28,6 +28,8 @@ static int two __maybe_unused = 2;
static int min_sndbuf = SOCK_MIN_SNDBUF;
static int min_rcvbuf = SOCK_MIN_RCVBUF;
static int max_skb_frags = MAX_SKB_FRAGS;
+static long long_one __maybe_unused = 1;
+static long long_max __maybe_unused = LONG_MAX;
static int net_msg_warn; /* Unused, but still a sysctl */
@@ -289,6 +291,17 @@ proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
}
+
+static int
+proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+}
#endif
static struct ctl_table net_core_table[] = {
@@ -398,10 +411,11 @@ static struct ctl_table net_core_table[] = {
{
.procname = "bpf_jit_limit",
.data = &bpf_jit_limit,
- .maxlen = sizeof(int),
+ .maxlen = sizeof(long),
.mode = 0600,
- .proc_handler = proc_dointvec_minmax_bpf_restricted,
- .extra1 = &one,
+ .proc_handler = proc_dolongvec_minmax_bpf_restricted,
+ .extra1 = &long_one,
+ .extra2 = &long_max,
},
#endif
{