4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Leonid Yegoshin <[email protected]> commit d65e5677ad5b3a49c43f60ec07644dc1f87bbd2e upstream. 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 <[email protected]> Reported-by: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/14043/ Signed-off-by: Ralf Baechle <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/mips/kernel/mips-r2-to-r6-emul.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- 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 *re 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 *re 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 *re 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);
