[mips,mipsel] Fix branch emulation of branch likely instructions.

svn path=/dists/sid/linux/; revision=21375

debian/changelog

@@ -92,6 +92,9 @@ linux (3.14.5-1) UNRELEASED; urgency=medium
   * [arm64] Initial kernel configuration and packaging (Closes: #745349).
   * [armhf] Add virtio-modules udeb.
 
+  [ Aurelien Jarno ]
+  * [mips,mipsel] Fix branch emulation of branch likely instructions. 
+
  -- Ben Hutchings <ben@decadent.org.uk>  Wed, 21 May 2014 21:24:50 +0100
 
 linux (3.14.4-1) unstable; urgency=high

debian/patches/bugfix/mips/MIPS-Fix-branch-emulation-of-branch-likely-instructi.patch

@@ -0,0 +1,65 @@
+From: Ralf Baechle <ralf@linux-mips.org>
+Date: Thu, 22 May 2014 23:19:00 +0200
+Subject: MIPS: Fix branch emulation of branch likely instructions.
+Origin: https://git.kernel.org/linus/41ca86e8502952116234fa558f4277092a5aaae9
+
+Two issues:
+
+  o For beql_op, beql_op, bne_op, bnel_op, blez_op, blezl_op, bgtz_op and
+    bgtzl_op the wrong field was being checked for the instruction opcode.
+  o For blez_op / blezl_op and bgtz_op / bgtzl_op the test was testing
+    for the wrong opcode.
+
+This bug got introduced by d8d4e3ae0b5c179c0bfd3f0af5b352d13bea9cfa [MIPS
+Kprobes: Refactor branch emulation].
+
+Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
+Acked-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
+Acked-by: Victor Kamensky <kamensky@cisco.com>
+---
+ arch/mips/kernel/branch.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
+index 4d78bf4..76122ff 100644
+--- a/arch/mips/kernel/branch.c
++++ b/arch/mips/kernel/branch.c
+@@ -317,7 +317,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
+ 		if (regs->regs[insn.i_format.rs] ==
+ 		    regs->regs[insn.i_format.rt]) {
+ 			epc = epc + 4 + (insn.i_format.simmediate << 2);
+-			if (insn.i_format.rt == beql_op)
++			if (insn.i_format.opcode == beql_op)
+ 				ret = BRANCH_LIKELY_TAKEN;
+ 		} else
+ 			epc += 8;
+@@ -329,7 +329,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
+ 		if (regs->regs[insn.i_format.rs] !=
+ 		    regs->regs[insn.i_format.rt]) {
+ 			epc = epc + 4 + (insn.i_format.simmediate << 2);
+-			if (insn.i_format.rt == bnel_op)
++			if (insn.i_format.opcode == bnel_op)
+ 				ret = BRANCH_LIKELY_TAKEN;
+ 		} else
+ 			epc += 8;
+@@ -341,7 +341,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
+ 		/* rt field assumed to be zero */
+ 		if ((long)regs->regs[insn.i_format.rs] <= 0) {
+ 			epc = epc + 4 + (insn.i_format.simmediate << 2);
+-			if (insn.i_format.rt == bnel_op)
++			if (insn.i_format.opcode == blezl_op)
+ 				ret = BRANCH_LIKELY_TAKEN;
+ 		} else
+ 			epc += 8;
+@@ -353,7 +353,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
+ 		/* rt field assumed to be zero */
+ 		if ((long)regs->regs[insn.i_format.rs] > 0) {
+ 			epc = epc + 4 + (insn.i_format.simmediate << 2);
+-			if (insn.i_format.rt == bnel_op)
++			if (insn.i_format.opcode == bgtzl_op)
+ 				ret = BRANCH_LIKELY_TAKEN;
+ 		} else
+ 			epc += 8;
+-- 
+2.0.0.rc0
+

debian/patches/series

@@ -88,3 +88,4 @@ debian/net-revert-lockdep-changes-in-3.14.5.patch
 debian/sockdiag-avoid-abi-change-in-3.14.5.patch
 debian/target-avoid-abi-change-in-3.14.5.patch
 debian/netfilter-avoid-abi-change-in-3.14.5.patch
+bugfix/mips/MIPS-Fix-branch-emulation-of-branch-likely-instructi.patch