bpf, x64: remove bpf_flush_icache

Unlike other archs flush_icache_range() is a noop on x64, therefore
remove the JIT's bpf_flush_icache() altogether since not needed.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 13 deletions

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index cbf94d44f3d5..eb661fff94d7 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -11,10 +11,10 @@
 #include <linux/netdevice.h>
 #include <linux/filter.h>
 #include <linux/if_vlan.h>
-#include <asm/cacheflush.h>
+#include <linux/bpf.h>
+
 #include <asm/set_memory.h>
 #include <asm/nospec-branch.h>
-#include <linux/bpf.h>
 
 /*
  * assembly code in arch/x86/net/bpf_jit.S
@@ -103,16 +103,6 @@ static int bpf_size_to_x86_bytes(int bpf_size)
 #define X86_JLE 0x7E
 #define X86_JG  0x7F
 
-static void bpf_flush_icache(void *start, void *end)
-{
-        mm_segment_t old_fs = get_fs();
-
-        set_fs(KERNEL_DS);
-        smp_wmb();
-        flush_icache_range((unsigned long)start, (unsigned long)end);
-        set_fs(old_fs);
-}
-
 #define CHOOSE_LOAD_FUNC(K, func) \
         ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
 
@@ -1266,7 +1256,6 @@ skip_init_addrs:
                 bpf_jit_dump(prog->len, proglen, pass + 1, image);
 
         if (image) {
-                bpf_flush_icache(header, image + proglen);
                 if (!prog->is_func || extra_pass) {
                         bpf_jit_binary_lock_ro(header);
                 } else {