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.le...@c-s.fr> --- Link to v3: https://patchwork.ozlabs.org/patch/1026042/ v4: Reviving this patch after one year. Now probe_user_read/write() is in the kernel so patch 1 is gone. v3: No change v2: Using probe_user_read() instead of probe_user_address() --- arch/powerpc/kernel/process.c | 12 +----------- arch/powerpc/kvm/book3s_64_mmu_radix.c | 6 ++---- arch/powerpc/mm/fault.c | 6 +----- arch/powerpc/oprofile/backtrace.c | 14 ++------------ arch/powerpc/perf/callchain.c | 20 +++----------------- arch/powerpc/perf/core-book3s.c | 8 +------- arch/powerpc/sysdev/fsl_pci.c | 10 ++++------ 7 files changed, 14 insertions(+), 62 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 4df94b6e2f32..79f2cb6ecf87 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1264,16 +1264,6 @@ 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) { @@ -1284,7 +1274,7 @@ 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 da857c8ba6e4..231410dc9db4 100644 --- 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 b5047f9b5dec..9e119f98a725 100644 --- 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 43245f4a9bcb..2799b922f780 100644 --- 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 35d542515faf..cbc251981209 100644 --- 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 48604625ab31..3086055bf681 100644 --- 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 617a443d673d..4a8874bc1057 100644 --- 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; -- 2.25.0
