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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2016-08-25 19:37:38 +0200
committerRalf Baechle <ralf@linux-mips.org>2017-01-03 16:34:41 +0100
commitd65e5677ad5b3a49c43f60ec07644dc1f87bbd2e (patch)
tree7c9d88ae587250d7756dfe48164052ab842c259a /arch/mips
parentMIPS: Loongson1B: Modify DEFAULT_MEMSIZE (diff)
downloadlinux-d65e5677ad5b3a49c43f60ec07644dc1f87bbd2e.tar.xz
linux-d65e5677ad5b3a49c43f60ec07644dc1f87bbd2e.zip
MIPS: R2-on-R6 MULTU/MADDU/MSUBU emulation bugfix
MIPS instructions MULTU, MADDU and MSUBU emulation requires registers HI/LO to be converted to signed 32bits before 64bit sign extension on MIPS64. Bug was found on running MIPS32 R2 test application on MIPS64 R6 kernel. Fixes: b0a668fb2038 ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6") Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Reported-by: Nikola.Veljkovic@imgtec.com Cc: paul.burton@imgtec.com Cc: yamada.masahiro@socionext.com Cc: akpm@linux-foundation.org Cc: andrea.gelmini@gelma.net Cc: macro@imgtec.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14043/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/kernel/mips-r2-to-r6-emul.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/mips/kernel/mips-r2-to-r6-emul.c b/arch/mips/kernel/mips-r2-to-r6-emul.c
index ef2ca28a028b..d8f1cf1ec370 100644
--- a/arch/mips/kernel/mips-r2-to-r6-emul.c
+++ b/arch/mips/kernel/mips-r2-to-r6-emul.c
@@ -433,8 +433,8 @@ static int multu_func(struct pt_regs *regs, u32 ir)
rs = regs->regs[MIPSInst_RS(ir)];
res = (u64)rt * (u64)rs;
rt = res;
- regs->lo = (s64)rt;
- regs->hi = (s64)(res >> 32);
+ regs->lo = (s64)(s32)rt;
+ regs->hi = (s64)(s32)(res >> 32);
MIPS_R2_STATS(muls);
@@ -670,9 +670,9 @@ static int maddu_func(struct pt_regs *regs, u32 ir)
res += ((((s64)rt) << 32) | (u32)rs);
rt = res;
- regs->lo = (s64)rt;
+ regs->lo = (s64)(s32)rt;
rs = res >> 32;
- regs->hi = (s64)rs;
+ regs->hi = (s64)(s32)rs;
MIPS_R2_STATS(dsps);
@@ -728,9 +728,9 @@ static int msubu_func(struct pt_regs *regs, u32 ir)
res = ((((s64)rt) << 32) | (u32)rs) - res;
rt = res;
- regs->lo = (s64)rt;
+ regs->lo = (s64)(s32)rt;
rs = res >> 32;
- regs->hi = (s64)rs;
+ regs->hi = (s64)(s32)rs;
MIPS_R2_STATS(dsps);