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authorDavid S. Miller <davem@davemloft.net>2018-12-15 10:58:32 -0800
committerDavid S. Miller <davem@davemloft.net>2018-12-15 10:58:32 -0800
commit10589a568f2ec531975504c98c1bed88c233a63d (patch)
treef2e986932c85bdbb5c1531fdd890b9f05664cf50 /kernel
parent143ece654f9f5b37bedea252a990be37e48ae3a5 (diff)
parent7640ead939247e91e84b7ec6ec001f30193cc7df (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says: ==================== pull-request: bpf 2018-12-15 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) fix liveness propagation of callee saved registers, from Jakub. 2) fix overflow in bpf_jit_limit knob, from Daniel. 3) bpf_flow_dissector api fix, from Stanislav. 4) bpf_perf_event api fix on powerpc, from Sandipan. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/core.c21
-rw-r--r--kernel/bpf/verifier.c13
2 files changed, 25 insertions, 9 deletions
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/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fc760d00a38c..51ba84d4d34a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5102,9 +5102,16 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
}
new_sl->next = env->explored_states[insn_idx];
env->explored_states[insn_idx] = new_sl;
- /* connect new state to parentage chain */
- for (i = 0; i < BPF_REG_FP; i++)
- cur_regs(env)[i].parent = &new->frame[new->curframe]->regs[i];
+ /* connect new state to parentage chain. Current frame needs all
+ * registers connected. Only r6 - r9 of the callers are alive (pushed
+ * to the stack implicitly by JITs) so in callers' frames connect just
+ * r6 - r9 as an optimization. Callers will have r1 - r5 connected to
+ * the state of the call instruction (with WRITTEN set), and r0 comes
+ * from callee with its full parentage chain, anyway.
+ */
+ for (j = 0; j <= cur->curframe; j++)
+ for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++)
+ cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i];
/* clear write marks in current state: the writes we did are not writes
* our child did, so they don't screen off its reads from us.
* (There are no read marks in current state, because reads always mark