mips: sanitize __access_ok()

for one thing, the last argument is always __access_mask and had been such
since 2.4.0-test3pre8; for another, it can bloody well be a static inline -
-O2 or -Os, __builtin_constant_p() propagates through static inline calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 20 insertions, 29 deletions

diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 70ca8eee166a..0c59911349ce 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -128,23 +128,14 @@ static inline bool eva_kernel_access(void)
  * this function, memory access functions may still return -EFAULT.
  */
 
-#define __access_mask get_fs().seg
-
-#define __access_ok(addr, size, mask)					\
-({									\
-	unsigned long __addr = (unsigned long) (addr);			\
-	unsigned long __size = size;					\
-	unsigned long __mask = mask;					\
-	unsigned long __ok;						\
-									\
-	__chk_user_ptr(addr);						\
-	__ok = (signed long)(__mask & (__addr | (__addr + __size) |	\
-		__ua_size(__size)));					\
-	__ok == 0;							\
-})
+static inline int __access_ok(const void __user *p, unsigned long size)
+{
+	unsigned long addr = (unsigned long)p;
+	return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
+}
 
 #define access_ok(type, addr, size)					\
-	likely(__access_ok((addr), (size), __access_mask))
+	likely(__access_ok((addr), (size)))
 
 /*
  * put_user: - Write a simple value into user space.
diff --git a/arch/mips/kernel/mips-r2-to-r6-emul.c b/arch/mips/kernel/mips-r2-to-r6-emul.c
index d8f1cf1ec370..550e7d03090a 100644
--- a/arch/mips/kernel/mips-r2-to-r6-emul.c
+++ b/arch/mips/kernel/mips-r2-to-r6-emul.c
@@ -1200,7 +1200,7 @@ fpu_emul:
 	case lwl_op:
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_READ, vaddr, 4)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1273,7 +1273,7 @@ fpu_emul:
 	case lwr_op:
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_READ, vaddr, 4)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1347,7 +1347,7 @@ fpu_emul:
 	case swl_op:
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1417,7 +1417,7 @@ fpu_emul:
 	case swr_op:
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1492,7 +1492,7 @@ fpu_emul:
 
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_READ, vaddr, 8)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1611,7 +1611,7 @@ fpu_emul:
 
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_READ, vaddr, 8)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1730,7 +1730,7 @@ fpu_emul:
 
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1848,7 +1848,7 @@ fpu_emul:
 
 		rt = regs->regs[MIPSInst_RT(inst)];
 		vaddr = regs->regs[MIPSInst_RS(inst)] + MIPSInst_SIMM(inst);
-		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGSEGV;
 			break;
@@ -1965,7 +1965,7 @@ fpu_emul:
 			err = SIGBUS;
 			break;
 		}
-		if (!access_ok(VERIFY_READ, vaddr, 4)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGBUS;
 			break;
@@ -2021,7 +2021,7 @@ fpu_emul:
 			err = SIGBUS;
 			break;
 		}
-		if (!access_ok(VERIFY_WRITE, vaddr, 4)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 4)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGBUS;
 			break;
@@ -2084,7 +2084,7 @@ fpu_emul:
 			err = SIGBUS;
 			break;
 		}
-		if (!access_ok(VERIFY_READ, vaddr, 8)) {
+		if (!access_ok(VERIFY_READ, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGBUS;
 			break;
@@ -2145,7 +2145,7 @@ fpu_emul:
 			err = SIGBUS;
 			break;
 		}
-		if (!access_ok(VERIFY_WRITE, vaddr, 8)) {
+		if (!access_ok(VERIFY_WRITE, (void __user *)vaddr, 8)) {
 			current->thread.cp0_baduaddr = vaddr;
 			err = SIGBUS;
 			break;
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index f1d17ece4181..1dfa7f5796c7 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -98,7 +98,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new)
 	if (unlikely(addr & 3))
 		return -EINVAL;
 
-	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
+	if (unlikely(!access_ok(VERIFY_WRITE, (const void __user *)addr, 4)))
 		return -EINVAL;
 
 	if (cpu_has_llsc && R10000_LLSC_WAR) {
diff --git a/arch/mips/oprofile/backtrace.c b/arch/mips/oprofile/backtrace.c
index 5e645c9a3162..16ace558cd9d 100644
--- a/arch/mips/oprofile/backtrace.c
+++ b/arch/mips/oprofile/backtrace.c
@@ -18,7 +18,7 @@ struct stackframe {
 static inline int get_mem(unsigned long addr, unsigned long *result)
 {
 	unsigned long *address = (unsigned long *) addr;
-	if (!access_ok(VERIFY_READ, addr, sizeof(unsigned long)))
+	if (!access_ok(VERIFY_READ, address, sizeof(unsigned long)))
 		return -1;
 	if (__copy_from_user_inatomic(result, address, sizeof(unsigned long)))
 		return -3;