diff options
| author | Markos Chandras <markos.chandras@imgtec.com> | 2014-11-25 15:54:14 (GMT) |
|---|---|---|
| committer | Markos Chandras <markos.chandras@imgtec.com> | 2015-02-17 15:37:31 (GMT) |
| commit | 5f9f41c474befb4ebbc40b27f65bb7d649241581 (patch) | |
| tree | 26108ad80ca556ac12466aac3f03fc29d0a8a4ca /arch | |
| parent | b5ad2c21934951bbf6aadd8adbdd9889baad0ac0 (diff) | |
| download | linux-5f9f41c474befb4ebbc40b27f65bb7d649241581.tar.xz | |
MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6
The MIPS R6 JR instruction is an alias to the JALR one, so it may
need emulation for non-R6 userlands.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/branch.h | 3 | ||||
| -rw-r--r-- | arch/mips/kernel/branch.c | 11 | ||||
| -rw-r--r-- | arch/mips/math-emu/cp1emu.c | 3 |
3 files changed, 15 insertions, 2 deletions
diff --git a/arch/mips/include/asm/branch.h b/arch/mips/include/asm/branch.h index de781cf..2894ea5 100644 --- a/arch/mips/include/asm/branch.h +++ b/arch/mips/include/asm/branch.h @@ -13,6 +13,9 @@ #include <asm/ptrace.h> #include <asm/inst.h> +static int mipsr2_emulation = 0; +#define NO_R6EMU (cpu_has_mips_r6 && !mipsr2_emulation) + extern int __isa_exception_epc(struct pt_regs *regs); extern int __compute_return_epc(struct pt_regs *regs); extern int __compute_return_epc_for_insn(struct pt_regs *regs, diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c index 4d7d99d..5736949 100644 --- a/arch/mips/kernel/branch.c +++ b/arch/mips/kernel/branch.c @@ -417,6 +417,8 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, regs->regs[insn.r_format.rd] = epc + 8; /* Fall through */ case jr_op: + if (NO_R6EMU && insn.r_format.func == jr_op) + goto sigill_r6; regs->cp0_epc = regs->regs[insn.r_format.rs]; break; } @@ -477,7 +479,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, case bposge32_op: if (!cpu_has_dsp) - goto sigill; + goto sigill_dsp; dspcontrol = rddsp(0x01); @@ -631,10 +633,15 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, return ret; -sigill: +sigill_dsp: printk("%s: DSP branch but not DSP ASE - sending SIGBUS.\n", current->comm); force_sig(SIGBUS, current); return -EFAULT; +sigill_r6: + pr_info("%s: R2 branch but r2-to-r6 emulator is not preset - sending SIGILL.\n", + current->comm); + force_sig(SIGILL, current); + return -EFAULT; } EXPORT_SYMBOL_GPL(__compute_return_epc_for_insn); diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 9dfcd7f..9bf8211 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -448,6 +448,9 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, dec_insn.next_pc_inc; /* Fall through */ case jr_op: + /* For R6, JR already emulated in jalr_op */ + if (NO_R6EMU && insn.r_format.opcode == jr_op) + break; *contpc = regs->regs[insn.r_format.rs]; return 1; } |