net: bpf: be friendly to kmemcheck
Reported by Mikulas Patocka, kmemcheck currently barks out a
false positive since we don't have special kmemcheck annotation
for bitfields used in bpf_prog structure.
We currently have jited:1, len:31 and thus when accessing len
while CONFIG_KMEMCHECK enabled, kmemcheck throws a warning that
we're reading uninitialized memory.
As we don't need the whole bit universe for pages member, we
can just split it to u16 and use a bool flag for jited instead
of a bitfield.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 2d1a5b9..6b45f649 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -933,7 +933,7 @@
set_memory_ro((unsigned long)header, header->pages);
fp->bpf_func = (void *)ctx.target;
- fp->jited = 1;
+ fp->jited = true;
out:
kfree(ctx.offsets);
return;
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index cfa83cf..0e97ccd 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1417,7 +1417,7 @@
bpf_jit_dump(fp->len, alloc_size, 2, ctx.target);
fp->bpf_func = (void *)ctx.target;
- fp->jited = 1;
+ fp->jited = true;
out:
kfree(ctx.offsets);
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 40c53ff..cbae2df 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -686,7 +686,7 @@
((u64 *)image)[0] = (u64)code_base;
((u64 *)image)[1] = local_paca->kernel_toc;
fp->bpf_func = (void *)image;
- fp->jited = 1;
+ fp->jited = true;
}
out:
kfree(addrs);
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index b734f97..555f5c7 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -842,7 +842,7 @@
if (jit.start) {
set_memory_ro((unsigned long)header, header->pages);
fp->bpf_func = (void *) jit.start;
- fp->jited = 1;
+ fp->jited = true;
}
out:
kfree(addrs);
diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c
index f7a736b..b2ad9dc 100644
--- a/arch/sparc/net/bpf_jit_comp.c
+++ b/arch/sparc/net/bpf_jit_comp.c
@@ -801,7 +801,7 @@
if (image) {
bpf_flush_icache(image, image + proglen);
fp->bpf_func = (void *)image;
- fp->jited = 1;
+ fp->jited = true;
}
out:
kfree(addrs);
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 9de0b54..d56cd1f 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -955,7 +955,7 @@
bpf_flush_icache(header, image + proglen);
set_memory_ro((unsigned long)header, header->pages);
prog->bpf_func = (void *)image;
- prog->jited = 1;
+ prog->jited = true;
}
out:
kfree(addrs);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 868764f..4b59ede 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -300,9 +300,9 @@
};
struct bpf_prog {
- u32 pages; /* Number of allocated pages */
- u32 jited:1, /* Is our filter JIT'ed? */
- len:31; /* Number of filter blocks */
+ u16 pages; /* Number of allocated pages */
+ bool jited; /* Is our filter JIT'ed? */
+ u32 len; /* Number of filter blocks */
struct sock_fprog_kern *orig_prog; /* Original BPF program */
struct bpf_work_struct *work; /* Deferred free work struct */
unsigned int (*bpf_func)(const struct sk_buff *skb,
diff --git a/net/core/filter.c b/net/core/filter.c
index fa5b7d0..dfc716f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -972,7 +972,7 @@
int err;
fp->bpf_func = NULL;
- fp->jited = 0;
+ fp->jited = false;
err = bpf_check_classic(fp->insns, fp->len);
if (err) {
