2 files changed, 130 insertions, 30 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 8e9fbe75894e..e97104302541 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -83,7 +83,8 @@ extern asmlinkage void handle_mcheck(void);
 extern asmlinkage void handle_reserved(void);
 
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
-        struct mips_fpu_struct *ctx, int has_fpu);
+                                    struct mips_fpu_struct *ctx, int has_fpu,
+                                    void *__user *fault_addr);
 
 void (*board_be_init)(void);
 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
@@ -661,12 +662,36 @@ asmlinkage void do_ov(struct pt_regs *regs)
         force_sig_info(SIGFPE, &info, current);
 }
 
+static int process_fpemu_return(int sig, void __user *fault_addr)
+{
+        if (sig == SIGSEGV || sig == SIGBUS) {
+                struct siginfo si = {0};
+                si.si_addr = fault_addr;
+                si.si_signo = sig;
+                if (sig == SIGSEGV) {
+                        if (find_vma(current->mm, (unsigned long)fault_addr))
+                                si.si_code = SEGV_ACCERR;
+                        else
+                                si.si_code = SEGV_MAPERR;
+                } else {
+                        si.si_code = BUS_ADRERR;
+                }
+                force_sig_info(sig, &si, current);
+                return 1;
+        } else if (sig) {
+                force_sig(sig, current);
+                return 1;
+        } else {
+                return 0;
+        }
+}
+
 /*
  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
  */
 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 {
-        siginfo_t info;
+        siginfo_t info = {0};
 
         if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
             == NOTIFY_STOP)
@@ -675,6 +700,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 
         if (fcr31 & FPU_CSR_UNI_X) {
                 int sig;
+                void __user *fault_addr = NULL;
 
                 /*
                  * Unimplemented operation exception.  If we've got the full
@@ -690,7 +716,8 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
                 lose_fpu(1);
 
                 /* Run the emulator */
-                sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
+                sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
+                                               &fault_addr);
 
                 /*
                  * We can't allow the emulated instruction to leave any of
@@ -702,8 +729,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
                 own_fpu(1);     /* Using the FPU again.  */
 
                 /* If something went wrong, signal */
-                if (sig)
-                        force_sig(sig, current);
+                process_fpemu_return(sig, fault_addr);
 
                 return;
         } else if (fcr31 & FPU_CSR_INV_X)
@@ -996,11 +1022,11 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 
                 if (!raw_cpu_has_fpu) {
                         int sig;
+                        void __user *fault_addr = NULL;
                         sig = fpu_emulator_cop1Handler(regs,
-                                                &current->thread.fpu, 0);
-                        if (sig)
-                                force_sig(sig, current);
-                        else
+                                                       &current->thread.fpu,
+                                                       0, &fault_addr);
+                        if (!process_fpemu_return(sig, fault_addr))
                                 mt_ase_fp_affinity();
                 }
 
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index b2ad1b0910ff..d32cb0503110 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -64,7 +64,7 @@ static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
 
 #if __mips >= 4 && __mips != 32
 static int fpux_emu(struct pt_regs *,
-        struct mips_fpu_struct *, mips_instruction);
+        struct mips_fpu_struct *, mips_instruction, void *__user *);
 #endif
 
 /* Further private data for which no space exists in mips_fpu_struct */
@@ -208,16 +208,23 @@ static inline int cop1_64bit(struct pt_regs *xcp)
  * Two instructions if the instruction is in a branch delay slot.
  */
 
-static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
+static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+                       void *__user *fault_addr)
 {
         mips_instruction ir;
         unsigned long emulpc, contpc;
         unsigned int cond;
 
-        if (get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
+        if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
                 MIPS_FPU_EMU_INC_STATS(errors);
+                *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
                 return SIGBUS;
         }
+        if (__get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
+                MIPS_FPU_EMU_INC_STATS(errors);
+                *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
+                return SIGSEGV;
+        }
 
         /* XXX NEC Vr54xx bug workaround */
         if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
@@ -245,10 +252,16 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 #endif
                         return SIGILL;
                 }
-                if (get_user(ir, (mips_instruction __user *) emulpc)) {
+                if (!access_ok(VERIFY_READ, emulpc, sizeof(mips_instruction))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = (mips_instruction __user *)emulpc;
                         return SIGBUS;
                 }
+                if (__get_user(ir, (mips_instruction __user *) emulpc)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = (mips_instruction __user *)emulpc;
+                        return SIGSEGV;
+                }
                 /* __compute_return_epc() will have updated cp0_epc */
                 contpc = xcp->cp0_epc;
                 /* In order not to confuse ptrace() et al, tweak context */
@@ -269,10 +282,17 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
                 u64 val;
 
                 MIPS_FPU_EMU_INC_STATS(loads);
-                if (get_user(val, va)) {
+
+                if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
                         return SIGBUS;
                 }
+                if (__get_user(val, va)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
+                        return SIGSEGV;
+                }
                 DITOREG(val, MIPSInst_RT(ir));
                 break;
         }
@@ -284,10 +304,16 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 
                 MIPS_FPU_EMU_INC_STATS(stores);
                 DIFROMREG(val, MIPSInst_RT(ir));
-                if (put_user(val, va)) {
+                if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
                         return SIGBUS;
                 }
+                if (__put_user(val, va)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
+                        return SIGSEGV;
+                }
                 break;
         }
 
@@ -297,10 +323,16 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
                 u32 val;
 
                 MIPS_FPU_EMU_INC_STATS(loads);
-                if (get_user(val, va)) {
+                if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
                         return SIGBUS;
                 }
+                if (__get_user(val, va)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
+                        return SIGSEGV;
+                }
                 SITOREG(val, MIPSInst_RT(ir));
                 break;
         }
@@ -312,10 +344,16 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 
                 MIPS_FPU_EMU_INC_STATS(stores);
                 SIFROMREG(val, MIPSInst_RT(ir));
-                if (put_user(val, va)) {
+                if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
                         return SIGBUS;
                 }
+                if (__put_user(val, va)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = va;
+                        return SIGSEGV;
+                }
                 break;
         }
 
@@ -440,11 +478,18 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
                                 contpc = (xcp->cp0_epc +
                                         (MIPSInst_SIMM(ir) << 2));
 
-                                if (get_user(ir,
-                                    (mips_instruction __user *) xcp->cp0_epc)) {
+                                if (!access_ok(VERIFY_READ, xcp->cp0_epc,
+                                               sizeof(mips_instruction))) {
                                         MIPS_FPU_EMU_INC_STATS(errors);
+                                        *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
                                         return SIGBUS;
                                 }
+                                if (__get_user(ir,
+                                    (mips_instruction __user *) xcp->cp0_epc)) {
+                                        MIPS_FPU_EMU_INC_STATS(errors);
+                                        *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
+                                        return SIGSEGV;
+                                }
 
                                 switch (MIPSInst_OPCODE(ir)) {
                                 case lwc1_op:
@@ -506,9 +551,8 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 
 #if __mips >= 4 && __mips != 32
         case cop1x_op:{
-                int sig;
-
-                if ((sig = fpux_emu(xcp, ctx, ir)))
+                int sig = fpux_emu(xcp, ctx, ir, fault_addr);
+                if (sig)
                         return sig;
                 break;
         }
@@ -604,7 +648,7 @@ DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
 
 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
-        mips_instruction ir)
+        mips_instruction ir, void *__user *fault_addr)
 {
         unsigned rcsr = 0;      /* resulting csr */
 
@@ -624,10 +668,16 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
                                 xcp->regs[MIPSInst_FT(ir)]);
 
                         MIPS_FPU_EMU_INC_STATS(loads);
-                        if (get_user(val, va)) {
+                        if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
                                 MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
                                 return SIGBUS;
                         }
+                        if (__get_user(val, va)) {
+                                MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
+                                return SIGSEGV;
+                        }
                         SITOREG(val, MIPSInst_FD(ir));
                         break;
 
@@ -638,10 +688,16 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
                         MIPS_FPU_EMU_INC_STATS(stores);
 
                         SIFROMREG(val, MIPSInst_FS(ir));
-                        if (put_user(val, va)) {
+                        if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
                                 MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
                                 return SIGBUS;
                         }
+                        if (put_user(val, va)) {
+                                MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
+                                return SIGSEGV;
+                        }
                         break;
 
                 case madd_s_op:
@@ -701,10 +757,16 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
                                 xcp->regs[MIPSInst_FT(ir)]);
 
                         MIPS_FPU_EMU_INC_STATS(loads);
-                        if (get_user(val, va)) {
+                        if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
                                 MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
                                 return SIGBUS;
                         }
+                        if (__get_user(val, va)) {
+                                MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
+                                return SIGSEGV;
+                        }
                         DITOREG(val, MIPSInst_FD(ir));
                         break;
 
@@ -714,10 +776,16 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 
                         MIPS_FPU_EMU_INC_STATS(stores);
                         DIFROMREG(val, MIPSInst_FS(ir));
-                        if (put_user(val, va)) {
+                        if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
                                 MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
                                 return SIGBUS;
                         }
+                        if (__put_user(val, va)) {
+                                MIPS_FPU_EMU_INC_STATS(errors);
+                                *fault_addr = va;
+                                return SIGSEGV;
+                        }
                         break;
 
                 case madd_d_op:
@@ -1242,7 +1310,7 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 }
 
 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
-        int has_fpu)
+        int has_fpu, void *__user *fault_addr)
 {
         unsigned long oldepc, prevepc;
         mips_instruction insn;
@@ -1252,10 +1320,16 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
         do {
                 prevepc = xcp->cp0_epc;
 
-                if (get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
+                if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
                         MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
                         return SIGBUS;
                 }
+                if (__get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
+                        MIPS_FPU_EMU_INC_STATS(errors);
+                        *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
+                        return SIGSEGV;
+                }
                 if (insn == 0)
                         xcp->cp0_epc += 4;      /* skip nops */
                 else {
@@ -1267,7 +1341,7 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
                          */
                         /* convert to ieee library modes */
                         ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
-                        sig = cop1Emulate(xcp, ctx);
+                        sig = cop1Emulate(xcp, ctx, fault_addr);
                         /* revert to mips rounding mode */
                         ieee754_csr.rm = mips_rm[ieee754_csr.rm];
                 }