diff options
Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 6efbb87f65ed..8fe35ed11fd6 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -46,6 +46,12 @@ static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) #define EMIT4_off32(b1, b2, b3, b4, off) \ do { EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) +#ifdef CONFIG_X86_KERNEL_IBT +#define EMIT_ENDBR() EMIT(gen_endbr(), 4) +#else +#define EMIT_ENDBR() +#endif + static bool is_imm8(int value) { return value <= 127 && value >= -128; @@ -241,7 +247,7 @@ struct jit_context { /* Number of bytes emit_patch() needs to generate instructions */ #define X86_PATCH_SIZE 5 /* Number of bytes that will be skipped on tailcall */ -#define X86_TAIL_CALL_OFFSET 11 +#define X86_TAIL_CALL_OFFSET (11 + ENDBR_INSN_SIZE) static void push_callee_regs(u8 **pprog, bool *callee_regs_used) { @@ -286,6 +292,7 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf, /* BPF trampoline can be made to work without these nops, * but let's waste 5 bytes for now and optimize later */ + EMIT_ENDBR(); memcpy(prog, x86_nops[5], X86_PATCH_SIZE); prog += X86_PATCH_SIZE; if (!ebpf_from_cbpf) { @@ -296,6 +303,10 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf, } EMIT1(0x55); /* push rbp */ EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ + + /* X86_TAIL_CALL_OFFSET is here */ + EMIT_ENDBR(); + /* sub rsp, rounded_stack_depth */ if (stack_depth) EMIT3_off32(0x48, 0x81, 0xEC, round_up(stack_depth, 8)); @@ -380,6 +391,13 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, /* BPF poking in modules is not supported */ return -EINVAL; + /* + * See emit_prologue(), for IBT builds the trampoline hook is preceded + * with an ENDBR instruction. + */ + if (is_endbr(*(u32 *)ip)) + ip += ENDBR_INSN_SIZE; + return __bpf_arch_text_poke(ip, t, old_addr, new_addr); } @@ -2013,14 +2031,18 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i ip_off = stack_size; - if (flags & BPF_TRAMP_F_SKIP_FRAME) + if (flags & BPF_TRAMP_F_SKIP_FRAME) { /* skip patched call instruction and point orig_call to actual * body of the kernel function. */ + if (is_endbr(*(u32 *)orig_call)) + orig_call += ENDBR_INSN_SIZE; orig_call += X86_PATCH_SIZE; + } prog = image; + EMIT_ENDBR(); EMIT1(0x55); /* push rbp */ EMIT3(0x48, 0x89, 0xE5); /* mov rbp, rsp */ EMIT4(0x48, 0x83, 0xEC, stack_size); /* sub rsp, stack_size */ |