diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 732c3a37d7b9..acfef06b8311 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -1134,6 +1134,14 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, /* * Branch taken: emulate dslot instruction */ + unsigned long bcpc; + + /* + * Remember EPC at the branch to point back + * at so that any delay-slot instruction + * signal is not silently ignored. + */ + bcpc = xcp->cp0_epc; xcp->cp0_epc += dec_insn.pc_inc; contpc = MIPSInst_SIMM(ir); @@ -1159,7 +1167,15 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, * Single step the non-CP1 * instruction in the dslot. */ - return mips_dsemul(xcp, ir, contpc); + sig = mips_dsemul(xcp, ir, + contpc); + if (sig) + xcp->cp0_epc = bcpc; + /* + * SIGILL forces out of + * the emulation loop. + */ + return sig ? sig : SIGILL; } } else contpc = (xcp->cp0_epc + (contpc << 2)); @@ -1174,7 +1190,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, if (cpu_has_mips_2_3_4_5_r) goto emul; - return SIGILL; + goto bc_sigill; case cop1_op: goto emul; @@ -1184,7 +1200,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, /* its one of ours */ goto emul; - return SIGILL; + goto bc_sigill; case spec_op: switch (MIPSInst_FUNC(ir)) { @@ -1192,16 +1208,24 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, if (cpu_has_mips_4_5_r) goto emul; - return SIGILL; + goto bc_sigill; } break; + + bc_sigill: + xcp->cp0_epc = bcpc; + return SIGILL; } /* * Single step the non-cp1 * instruction in the dslot */ - return mips_dsemul(xcp, ir, contpc); + sig = mips_dsemul(xcp, ir, contpc); + if (sig) + xcp->cp0_epc = bcpc; + /* SIGILL forces out of the emulation loop. */ + return sig ? sig : SIGILL; } else if (likely) { /* branch not taken */ /* * branch likely nullifies diff --git a/arch/mips/math-emu/dsemul.c b/arch/mips/math-emu/dsemul.c index 00ad7365e453..e0b5cc27d78b 100644 --- a/arch/mips/math-emu/dsemul.c +++ b/arch/mips/math-emu/dsemul.c @@ -96,7 +96,7 @@ int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc) flush_cache_sigtramp((unsigned long)&fr->emul); - return SIGILL; /* force out of emulation loop */ + return 0; } int do_dsemulret(struct pt_regs *xcp)