netdev - [PATCH 12/17] MIPS: bpf: Fix is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 23 Jun 2014 10:38:55 +0100
From:	Markos Chandras <markos.chandras@...tec.com>
To:	<linux-mips@...ux-mips.org>
CC:	Markos Chandras <markos.chandras@...tec.com>,
	"David S. Miller" <davem@...emloft.net>,
	Daniel Borkmann <dborkman@...hat.com>,
	"Alexei Starovoitov" <ast@...mgrid.com>, <netdev@...r.kernel.org>
Subject: [PATCH 12/17] MIPS: bpf: Fix is_range() semantics

is_range() was meant to check whether the number is within
the s16 range or not. However the return values and consumers expected
the exact opposite. We fix that by inverting the logic in the function
to return 'true' for < s16 and 'false' for > s16.

Reported-by: Alexei Starovoitov <ast@...mgrid.com>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Daniel Borkmann <dborkman@...hat.com>
Cc: Alexei Starovoitov <ast@...mgrid.com>
Cc: netdev@...r.kernel.org
Signed-off-by: Markos Chandras <markos.chandras@...tec.com>
---
 arch/mips/net/bpf_jit.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 1d228d27d759..00c4c83972bb 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -166,9 +166,7 @@ do {							\
 /* Determine if immediate is within the 16-bit signed range */
 static inline bool is_range16(s32 imm)
 {
-	if (imm >= SBIT(15) || imm < -SBIT(15))
-		return true;
-	return false;
+	return !(imm >= SBIT(15) || imm < -SBIT(15));
 }
 
 static inline void emit_addu(unsigned int dst, unsigned int src1,
@@ -187,7 +185,7 @@ static inline void emit_load_imm(unsigned int dst, u32 imm, struct jit_ctx *ctx)
 {
 	if (ctx->target != NULL) {
 		/* addiu can only handle s16 */
-		if (is_range16(imm)) {
+		if (!is_range16(imm)) {
 			u32 *p = &ctx->target[ctx->idx];
 			uasm_i_lui(&p, r_tmp_imm, (s32)imm >> 16);
 			p = &ctx->target[ctx->idx + 1];
@@ -199,7 +197,7 @@ static inline void emit_load_imm(unsigned int dst, u32 imm, struct jit_ctx *ctx)
 	}
 	ctx->idx++;
 
-	if (is_range16(imm))
+	if (!is_range16(imm))
 		ctx->idx++;
 }
 
@@ -240,7 +238,7 @@ static inline void emit_daddiu(unsigned int dst, unsigned int src,
 static inline void emit_addiu(unsigned int dst, unsigned int src,
 			      u32 imm, struct jit_ctx *ctx)
 {
-	if (is_range16(imm)) {
+	if (!is_range16(imm)) {
 		emit_load_imm(r_tmp, imm, ctx);
 		emit_addu(dst, r_tmp, src, ctx);
 	} else {
@@ -347,7 +345,7 @@ static inline void emit_sltiu(unsigned dst, unsigned int src,
 			      unsigned int imm, struct jit_ctx *ctx)
 {
 	/* 16 bit immediate */
-	if (is_range16((s32)imm)) {
+	if (!is_range16((s32)imm)) {
 		emit_load_imm(r_tmp, imm, ctx);
 		emit_sltu(dst, src, r_tmp, ctx);
 	} else {
-- 
2.0.0

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html