From 83e230739cb578049f62c626946e04a79b46c85b Mon Sep 17 00:00:00 2001
From: Kevin Mihelich <kevin@archlinuxarm.org>
Date: Mon, 29 Sep 2014 12:14:00 -0600
Subject: [PATCH] Backport BFP XOR operation
Squashed commit of the following:
commit 210b6dd797945571a92ae1f502be6b885cdeae23
Author: Daniel Borkmann <dxchgb@gmail.com>
Date: Mon Sep 24 02:23:59 2012 +0000
filter: add XOR instruction for use with X/K
SKF_AD_ALU_XOR_X has been added a while ago, but as an 'ancillary'
operation that is invoked through a negative offset in K within BPF
load operations. Since BPF_MOD has recently been added, BPF_XOR should
also be part of the common ALU operations. Removing SKF_AD_ALU_XOR_X
might not be an option since this is exposed to user space.
Signed-off-by: Daniel Borkmann <daniel.borkmann@tik.ee.ethz.ch>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 11acc6e3fc94f8b18483af729760b9025d708409
Author: Eric Dumazet <edumazet@google.com>
Date: Fri Sep 7 22:03:35 2012 +0000
filter: add MOD operation
Add a new ALU opcode, to compute a modulus.
Commit ffe06c17afbbb used an ancillary to implement XOR_X,
but here we reserve one of the available ALU opcode to implement both
MOD_X and MOD_K
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: George Bakos <gbakos@alpinista.org>
Cc: Jay Schulist <jschlst@samba.org>
Cc: Jiri Pirko <jpirko@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 3026fca84f0230d96693ba6d3e6089343874ca09
Author: Daniel Borkmann <dxchgb@gmail.com>
Date: Mon Sep 24 07:34:51 2012 +0000
x86: bpf_jit_comp: add XOR instruction for BPF JIT
This patch is a follow-up for patch "filter: add XOR instruction for use
with X/K" that implements BPF x86 JIT parts for the BPF XOR operation.
Signed-off-by: Daniel Borkmann <daniel.borkmann@tik.ee.ethz.ch>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit cf2f055d4abff198aaa0128aa06e458a6ff767d7
Author: Eric Dumazet <edumazet@google.com>
Date: Mon Jun 4 21:26:30 2012 +0000
x86 bpf_jit: support BPF_S_ANC_ALU_XOR_X instruction
commit ffe06c17afbb (filter: add XOR operation) added generic support
for XOR operation.
This patch implements the XOR instruction in x86 jit.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit e0d7a646c8684dac88c6ebbeb155313ad7fc624d
Author: Jiri Pirko <jpirko@redhat.com>
Date: Sat Mar 31 11:01:20 2012 +0000
filter: add XOR operation
Add XOR instruction fo BPF machine. Needed for computing packet hashes.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
arch/x86/net/bpf_jit_comp.c | 13 +++++++++++++
include/linux/filter.h | 11 ++++++++++-
net/core/filter.c | 25 +++++++++++++++++++++++++
3 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 0597f95..db99f9a 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -309,6 +309,19 @@ void bpf_jit_compile(struct sk_filter *fp)
else
EMIT1_off32(0x0d, K); /* or imm32,%eax */
break;
+ case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
+ case BPF_S_ALU_XOR_X:
+ seen |= SEEN_XREG;
+ EMIT2(0x31, 0xd8); /* xor %ebx,%eax */
+ break;
+ case BPF_S_ALU_XOR_K: /* A ^= K; */
+ if (K == 0)
+ break;
+ if (is_imm8(K))
+ EMIT3(0x83, 0xf0, K); /* xor imm8,%eax */
+ else
+ EMIT1_off32(0x35, K); /* xor imm32,%eax */
+ break;
case BPF_S_ALU_LSH_X: /* A <<= X; */
seen |= SEEN_XREG;
EMIT4(0x89, 0xd9, 0xd3, 0xe0); /* mov %ebx,%ecx; shl %cl,%eax */
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 8eeb205..0031feb 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -73,6 +73,9 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */
#define BPF_LSH 0x60
#define BPF_RSH 0x70
#define BPF_NEG 0x80
+#define BPF_MOD 0x90
+#define BPF_XOR 0xa0
+
#define BPF_JA 0x00
#define BPF_JEQ 0x10
#define BPF_JGT 0x20
@@ -126,7 +129,8 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */
#define SKF_AD_HATYPE 28
#define SKF_AD_RXHASH 32
#define SKF_AD_CPU 36
-#define SKF_AD_MAX 40
+#define SKF_AD_ALU_XOR_X 40
+#define SKF_AD_MAX 44
#define SKF_NET_OFF (-0x100000)
#define SKF_LL_OFF (-0x200000)
@@ -181,10 +185,14 @@ enum {
BPF_S_ALU_MUL_K,
BPF_S_ALU_MUL_X,
BPF_S_ALU_DIV_X,
+ BPF_S_ALU_MOD_K,
+ BPF_S_ALU_MOD_X,
BPF_S_ALU_AND_K,
BPF_S_ALU_AND_X,
BPF_S_ALU_OR_K,
BPF_S_ALU_OR_X,
+ BPF_S_ALU_XOR_K,
+ BPF_S_ALU_XOR_X,
BPF_S_ALU_LSH_K,
BPF_S_ALU_LSH_X,
BPF_S_ALU_RSH_K,
@@ -228,6 +236,7 @@ enum {
BPF_S_ANC_HATYPE,
BPF_S_ANC_RXHASH,
BPF_S_ANC_CPU,
+ BPF_S_ANC_ALU_XOR_X,
};
#endif /* __KERNEL__ */
diff --git a/net/core/filter.c b/net/core/filter.c
index 3b7398a..26c7bbe 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -158,6 +158,14 @@ unsigned int sk_run_filter(const struct sk_buff *skb,
case BPF_S_ALU_DIV_K:
A = reciprocal_divide(A, K);
continue;
+ case BPF_S_ALU_MOD_X:
+ if (X == 0)
+ return 0;
+ A %= X;
+ continue;
+ case BPF_S_ALU_MOD_K:
+ A %= K;
+ continue;
case BPF_S_ALU_AND_X:
A &= X;
continue;
@@ -170,6 +178,13 @@ unsigned int sk_run_filter(const struct sk_buff *skb,
case BPF_S_ALU_OR_K:
A |= K;
continue;
+ case BPF_S_ANC_ALU_XOR_X:
+ case BPF_S_ALU_XOR_X:
+ A ^= X;
+ continue;
+ case BPF_S_ALU_XOR_K:
+ A ^= K;
+ continue;
case BPF_S_ALU_LSH_X:
A <<= X;
continue;
@@ -456,10 +471,14 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen)
[BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K,
[BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X,
[BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X,
+ [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K,
+ [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X,
[BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K,
[BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X,
[BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K,
[BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X,
+ [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K,
+ [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X,
[BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K,
[BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X,
[BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K,
@@ -518,6 +537,11 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen)
return -EINVAL;
ftest->k = reciprocal_value(ftest->k);
break;
+ case BPF_S_ALU_MOD_K:
+ /* check for division by zero */
+ if (ftest->k == 0)
+ return -EINVAL;
+ break;
case BPF_S_LD_MEM:
case BPF_S_LDX_MEM:
case BPF_S_ST:
@@ -565,6 +589,7 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen)
ANCILLARY(HATYPE);
ANCILLARY(RXHASH);
ANCILLARY(CPU);
+ ANCILLARY(ALU_XOR_X);
}
}
ftest->code = code;
--
2.1.1