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authorSong Liu <song@kernel.org>2022-09-26 11:47:38 -0700
committerAlexei Starovoitov <ast@kernel.org>2022-09-26 20:40:43 -0700
commit19c02415da2345d0dda2b5c4495bc17cc14b18b5 (patch)
tree64cebe945349bf772b0d4cdb212ee1fc55d38215 /arch
parent30b8fdbbe31b2422f46fcd6d3960e563affe76d7 (diff)
bpf: use bpf_prog_pack for bpf_dispatcher
Allocate bpf_dispatcher with bpf_prog_pack_alloc so that bpf_dispatcher can share pages with bpf programs. arch_prepare_bpf_dispatcher() is updated to provide a RW buffer as working area for arch code to write to. This also fixes CPA W^X warnning like: CPA refuse W^X violation: 8000000000000163 -> 0000000000000163 range: ... Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20220926184739.3512547-2-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/net/bpf_jit_comp.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index d4a6183197e9..35796db58116 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -2242,7 +2242,7 @@ cleanup:
return ret;
}
-static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
+static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs, u8 *image, u8 *buf)
{
u8 *jg_reloc, *prog = *pprog;
int pivot, err, jg_bytes = 1;
@@ -2258,12 +2258,12 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
EMIT2_off32(0x81, add_1reg(0xF8, BPF_REG_3),
progs[a]);
err = emit_cond_near_jump(&prog, /* je func */
- (void *)progs[a], prog,
+ (void *)progs[a], image + (prog - buf),
X86_JE);
if (err)
return err;
- emit_indirect_jump(&prog, 2 /* rdx */, prog);
+ emit_indirect_jump(&prog, 2 /* rdx */, image + (prog - buf));
*pprog = prog;
return 0;
@@ -2288,7 +2288,7 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
jg_reloc = prog;
err = emit_bpf_dispatcher(&prog, a, a + pivot, /* emit lower_part */
- progs);
+ progs, image, buf);
if (err)
return err;
@@ -2302,7 +2302,7 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
emit_code(jg_reloc - jg_bytes, jg_offset, jg_bytes);
err = emit_bpf_dispatcher(&prog, a + pivot + 1, /* emit upper_part */
- b, progs);
+ b, progs, image, buf);
if (err)
return err;
@@ -2322,12 +2322,12 @@ static int cmp_ips(const void *a, const void *b)
return 0;
}
-int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs)
+int arch_prepare_bpf_dispatcher(void *image, void *buf, s64 *funcs, int num_funcs)
{
- u8 *prog = image;
+ u8 *prog = buf;
sort(funcs, num_funcs, sizeof(funcs[0]), cmp_ips, NULL);
- return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs);
+ return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs, image, buf);
}
struct x64_jit_data {