powerpc: use probe_user_read() and probe_user_write()

Instead of opencoding, use probe_user_read() to failessly read
a user location and probe_user_write() for writing to user.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 7fcf72e..fad50db 100644 (file)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1277,16 +1277,6 @@ void show_user_instructions(struct pt_regs *regs)
 
        pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
 
-       /*
-        * Make sure the NIP points at userspace, not kernel text/data or
-        * elsewhere.
-        */
-       if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {
-               pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
-                       current->comm, current->pid);
-               return;
-       }
-
        seq_buf_init(&s, buf, sizeof(buf));
 
        while (n) {
@@ -1297,7 +1287,7 @@ void show_user_instructions(struct pt_regs *regs)
                for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
                        int instr;
 
-                       if (probe_kernel_address((const void *)pc, instr)) {
+                       if (probe_user_read(&instr, (void __user *)pc, sizeof(instr))) {
                                seq_buf_printf(&s, "XXXXXXXX ");
                                continue;
                        }

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index da857c8..231410d 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -63,12 +63,10 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
        }
        isync();
 
-       pagefault_disable();
        if (is_load)
-               ret = raw_copy_from_user(to, from, n);
+               ret = probe_user_read(to, (const void __user *)from, n);
        else
-               ret = raw_copy_to_user(to, from, n);
-       pagefault_enable();
+               ret = probe_user_write((void __user *)to, from, n);
 
        /* switch the pid first to avoid running host with unallocated pid */
        if (quadrant == 1 && pid != old_pid)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index b5047f9..9e119f9 100644 (file)
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -279,12 +279,8 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address,
                if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) &&
                    access_ok(nip, sizeof(*nip))) {
                        unsigned int inst;
-                       int res;
 
-                       pagefault_disable();
-                       res = __get_user_inatomic(inst, nip);
-                       pagefault_enable();
-                       if (!res)
+                       if (!probe_user_read(&inst, nip, sizeof(inst)))
                                return !store_updates_sp(inst);
                        *must_retry = true;
                }

diff --git a/arch/powerpc/oprofile/backtrace.c b/arch/powerpc/oprofile/backtrace.c
index 43245f4..2799b92 100644 (file)
--- a/arch/powerpc/oprofile/backtrace.c
+++ b/arch/powerpc/oprofile/backtrace.c
@@ -28,15 +28,12 @@ static unsigned int user_getsp32(unsigned int sp, int is_first)
        unsigned int stack_frame[2];
        void __user *p = compat_ptr(sp);
 
-       if (!access_ok(p, sizeof(stack_frame)))
-               return 0;
-
        /*
         * The most likely reason for this is that we returned -EFAULT,
         * which means that we've done all that we can do from
         * interrupt context.
         */
-       if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame)))
+       if (probe_user_read(stack_frame, (void __user *)p, sizeof(stack_frame)))
                return 0;
 
        if (!is_first)
@@ -54,11 +51,7 @@ static unsigned long user_getsp64(unsigned long sp, int is_first)
 {
        unsigned long stack_frame[3];
 
-       if (!access_ok((void __user *)sp, sizeof(stack_frame)))
-               return 0;
-
-       if (__copy_from_user_inatomic(stack_frame, (void __user *)sp,
-                                       sizeof(stack_frame)))
+       if (probe_user_read(stack_frame, (void __user *)sp, sizeof(stack_frame)))
                return 0;
 
        if (!is_first)
@@ -103,7 +96,6 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
                        first_frame = 0;
                }
        } else {
-               pagefault_disable();
 #ifdef CONFIG_PPC64
                if (!is_32bit_task()) {
                        while (depth--) {
@@ -112,7 +104,6 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
                                        break;
                                first_frame = 0;
                        }
-                       pagefault_enable();
                        return;
                }
 #endif
@@ -123,6 +114,5 @@ void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
                                break;
                        first_frame = 0;
                }
-               pagefault_enable();
        }
 }

diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index 35d5425..cbc2519 100644 (file)
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -155,12 +155,8 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
            ((unsigned long)ptr & 7))
                return -EFAULT;
 
-       pagefault_disable();
-       if (!__get_user_inatomic(*ret, ptr)) {
-               pagefault_enable();
+       if (!probe_user_read(ret, ptr, sizeof(*ret)))
                return 0;
-       }
-       pagefault_enable();
 
        return read_user_stack_slow(ptr, ret, 8);
 }
@@ -171,12 +167,8 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
            ((unsigned long)ptr & 3))
                return -EFAULT;
 
-       pagefault_disable();
-       if (!__get_user_inatomic(*ret, ptr)) {
-               pagefault_enable();
+       if (!probe_user_read(ret, ptr, sizeof(*ret)))
                return 0;
-       }
-       pagefault_enable();
 
        return read_user_stack_slow(ptr, ret, 4);
 }
@@ -293,17 +285,11 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
  */
 static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
 {
-       int rc;
-
        if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
            ((unsigned long)ptr & 3))
                return -EFAULT;
 
-       pagefault_disable();
-       rc = __get_user_inatomic(*ret, ptr);
-       pagefault_enable();
-
-       return rc;
+       return probe_user_read(ret, ptr, sizeof(*ret));
 }
 
 static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 4860462..3086055 100644 (file)
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -415,7 +415,6 @@ static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in)
 static __u64 power_pmu_bhrb_to(u64 addr)
 {
        unsigned int instr;
-       int ret;
        __u64 target;
 
        if (is_kernel_addr(addr)) {
@@ -426,13 +425,8 @@ static __u64 power_pmu_bhrb_to(u64 addr)
        }
 
        /* Userspace: need copy instruction here then translate it */
-       pagefault_disable();
-       ret = __get_user_inatomic(instr, (unsigned int __user *)addr);
-       if (ret) {
-               pagefault_enable();
+       if (probe_user_read(&instr, (unsigned int __user *)addr, sizeof(instr)))
                return 0;
-       }
-       pagefault_enable();
 
        target = branch_target(&instr);
        if ((!target) || (instr & BRANCH_ABSOLUTE))

diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 617a443..4a8874b 100644 (file)
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1065,13 +1065,11 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
        addr += mfspr(SPRN_MCAR);
 
        if (is_in_pci_mem_space(addr)) {
-               if (user_mode(regs)) {
-                       pagefault_disable();
-                       ret = get_user(inst, (__u32 __user *)regs->nip);
-                       pagefault_enable();
-               } else {
+               if (user_mode(regs))
+                       ret = probe_user_read(&inst, (void __user *)regs->nip,
+                                             sizeof(inst));
+               else
                        ret = probe_kernel_address((void *)regs->nip, inst);
-               }
 
                if (!ret && mcheck_handle_load(regs, inst)) {
                        regs->nip += 4;