From 286aad3c4014ca825c447e07e24f8929e6d266d2 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 8 Sep 2014 08:04:49 +0200 Subject: [PATCH] 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 Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- arch/arm/net/bpf_jit_32.c | 2 +- arch/mips/net/bpf_jit.c | 2 +- arch/powerpc/net/bpf_jit_comp.c | 2 +- arch/s390/net/bpf_jit_comp.c | 2 +- arch/sparc/net/bpf_jit_comp.c | 2 +- arch/x86/net/bpf_jit_comp.c | 2 +- include/linux/filter.h | 6 +++--- net/core/filter.c | 2 +- 8 files changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 2d1a5b93d91c..6b45f649eff0 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -933,7 +933,7 @@ void bpf_jit_compile(struct bpf_prog *fp) 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 cfa83cf2447d..0e97ccd29fe3 100644 --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -1417,7 +1417,7 @@ void bpf_jit_compile(struct bpf_prog *fp) 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 40c53ff59124..cbae2dfd053c 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -686,7 +686,7 @@ void bpf_jit_compile(struct bpf_prog *fp) ((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 b734f975c22e..555f5c7e83ab 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -842,7 +842,7 @@ void bpf_jit_compile(struct bpf_prog *fp) 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 f7a736b645e8..b2ad9dc5425e 100644 --- a/arch/sparc/net/bpf_jit_comp.c +++ b/arch/sparc/net/bpf_jit_comp.c @@ -801,7 +801,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; 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 9de0b5476b0c..d56cd1f515bd 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -955,7 +955,7 @@ void bpf_int_jit_compile(struct bpf_prog *prog) 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 868764fcffb8..4b59edead908 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -300,9 +300,9 @@ struct bpf_work_struct { }; 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 fa5b7d0f77ac..dfc716ffa44b 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -972,7 +972,7 @@ static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp) int err; fp->bpf_func = NULL; - fp->jited = 0; + fp->jited = false; err = bpf_check_classic(fp->insns, fp->len); if (err) {