diff options
Diffstat (limited to 'kernel/bpf/core.c')
-rw-r--r-- | kernel/bpf/core.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 66088a9e9b9e..673f5d40a93e 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -30,7 +30,7 @@ #include <linux/kallsyms.h> #include <linux/rcupdate.h> #include <linux/perf_event.h> - +#include <linux/extable.h> #include <asm/unaligned.h> /* Registers */ @@ -712,6 +712,24 @@ bool is_bpf_text_address(unsigned long addr) return ret; } +const struct exception_table_entry *search_bpf_extables(unsigned long addr) +{ + const struct exception_table_entry *e = NULL; + struct bpf_prog *prog; + + rcu_read_lock(); + prog = bpf_prog_kallsyms_find(addr); + if (!prog) + goto out; + if (!prog->aux->num_exentries) + goto out; + + e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr); +out: + rcu_read_unlock(); + return e; +} + int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *sym) { @@ -1291,6 +1309,11 @@ bool bpf_opcode_in_insntable(u8 code) } #ifndef CONFIG_BPF_JIT_ALWAYS_ON +u64 __weak bpf_probe_read(void * dst, u32 size, const void * unsafe_ptr) +{ + memset(dst, 0, size); + return -EFAULT; +} /** * __bpf_prog_run - run eBPF program on a given context * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers @@ -1310,6 +1333,10 @@ static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u6 /* Non-UAPI available opcodes. */ [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, + [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B, + [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H, + [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W, + [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW, }; #undef BPF_INSN_3_LBL #undef BPF_INSN_2_LBL @@ -1542,6 +1569,16 @@ out: LDST(W, u32) LDST(DW, u64) #undef LDST +#define LDX_PROBE(SIZEOP, SIZE) \ + LDX_PROBE_MEM_##SIZEOP: \ + bpf_probe_read(&DST, SIZE, (const void *)(long) SRC); \ + CONT; + LDX_PROBE(B, 1) + LDX_PROBE(H, 2) + LDX_PROBE(W, 4) + LDX_PROBE(DW, 8) +#undef LDX_PROBE + STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ atomic_add((u32) SRC, (atomic_t *)(unsigned long) (DST + insn->off)); |