diff options
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 55 |
1 files changed, 49 insertions, 6 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 1a796e0799ec..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) { @@ -672,6 +681,40 @@ void __weak bpf_jit_free(struct bpf_prog *fp) bpf_prog_unlock_free(fp); } +int bpf_jit_get_func_addr(const struct bpf_prog *prog, + const struct bpf_insn *insn, bool extra_pass, + u64 *func_addr, bool *func_addr_fixed) +{ + s16 off = insn->off; + s32 imm = insn->imm; + u8 *addr; + + *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; + if (!*func_addr_fixed) { + /* Place-holder address till the last pass has collected + * all addresses for JITed subprograms in which case we + * can pick them up from prog->aux. + */ + if (!extra_pass) + addr = NULL; + else if (prog->aux->func && + off >= 0 && off < prog->aux->func_cnt) + addr = (u8 *)prog->aux->func[off]->bpf_func; + else + return -EINVAL; + } else { + /* Address of a BPF helper call. Since part of the core + * kernel, it's always at a fixed location. __bpf_call_base + * and the helper with imm relative to it are both in core + * kernel. + */ + addr = (u8 *)__bpf_call_base + imm; + } + + *func_addr = (unsigned long)addr; + return 0; +} + static int bpf_jit_blind_insn(const struct bpf_insn *from, const struct bpf_insn *aux, struct bpf_insn *to_buff) |