From fe557319aa06c23cffc9346000f119547e0f289a Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Wed, 17 Jun 2020 09:37:53 +0200
Subject: maccess: rename probe_kernel_{read,write} to
 copy_{from,to}_kernel_nofault

Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/uaccess.h | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

(limited to 'include')

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 7bcadca22100..70a3d9cd9113 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -301,13 +301,14 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
 	return 0;
 }
 
-bool probe_kernel_read_allowed(const void *unsafe_src, size_t size);
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
 
-extern long probe_kernel_read(void *dst, const void *src, size_t size);
-extern long probe_user_read(void *dst, const void __user *src, size_t size);
+long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
+long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);
 
-extern long notrace probe_kernel_write(void *dst, const void *src, size_t size);
-extern long notrace probe_user_write(void __user *dst, const void *src, size_t size);
+extern long probe_user_read(void *dst, const void __user *src, size_t size);
+extern long notrace probe_user_write(void __user *dst, const void *src,
+		size_t size);
 
 long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
 		long count);
@@ -324,7 +325,7 @@ long strnlen_user_nofault(const void __user *unsafe_addr, long count);
  * Returns 0 on success, or -EFAULT.
  */
 #define probe_kernel_address(addr, retval)		\
-	probe_kernel_read(&retval, addr, sizeof(retval))
+	copy_from_kernel_nofault(&retval, addr, sizeof(retval))
 
 #ifndef user_access_begin
 #define user_access_begin(ptr,len) access_ok(ptr, len)
-- 
cgit v1.2.3-59-g8ed1b


From c0ee37e85e0e47402b8bbe35b6cec8e06937ca58 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Wed, 17 Jun 2020 09:37:54 +0200
Subject: maccess: rename probe_user_{read,write} to
 copy_{from,to}_user_nofault

Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/powerpc/kernel/process.c          |  3 ++-
 arch/powerpc/kvm/book3s_64_mmu_radix.c |  4 ++--
 arch/powerpc/lib/inst.c                |  6 +++---
 arch/powerpc/oprofile/backtrace.c      |  6 ++++--
 arch/powerpc/perf/callchain_32.c       |  2 +-
 arch/powerpc/perf/callchain_64.c       |  2 +-
 arch/powerpc/perf/core-book3s.c        |  3 ++-
 arch/powerpc/sysdev/fsl_pci.c          |  4 ++--
 include/linux/uaccess.h                |  4 ++--
 kernel/trace/bpf_trace.c               |  4 ++--
 kernel/trace/trace_kprobe.c            |  2 +-
 mm/maccess.c                           | 12 ++++++------
 12 files changed, 28 insertions(+), 24 deletions(-)

(limited to 'include')

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 7bb7faf84490..d4d0d1048500 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1305,7 +1305,8 @@ void show_user_instructions(struct pt_regs *regs)
 		for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
 			int instr;
 
-			if (probe_user_read(&instr, (void __user *)pc, sizeof(instr))) {
+			if (copy_from_user_nofault(&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 3cb0c9843d01..e738ea652192 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -64,9 +64,9 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
 	isync();
 
 	if (is_load)
-		ret = probe_user_read(to, (const void __user *)from, n);
+		ret = copy_from_user_nofault(to, (const void __user *)from, n);
 	else
-		ret = probe_user_write((void __user *)to, from, n);
+		ret = copy_to_user_nofault((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/lib/inst.c b/arch/powerpc/lib/inst.c
index 6c7a20af9fd6..9cc17eb62462 100644
--- a/arch/powerpc/lib/inst.c
+++ b/arch/powerpc/lib/inst.c
@@ -15,11 +15,11 @@ int probe_user_read_inst(struct ppc_inst *inst,
 	unsigned int val, suffix;
 	int err;
 
-	err = probe_user_read(&val, nip, sizeof(val));
+	err = copy_from_user_nofault(&val, nip, sizeof(val));
 	if (err)
 		return err;
 	if (get_op(val) == OP_PREFIX) {
-		err = probe_user_read(&suffix, (void __user *)nip + 4, 4);
+		err = copy_from_user_nofault(&suffix, (void __user *)nip + 4, 4);
 		*inst = ppc_inst_prefix(val, suffix);
 	} else {
 		*inst = ppc_inst(val);
@@ -51,7 +51,7 @@ int probe_user_read_inst(struct ppc_inst *inst,
 	unsigned int val;
 	int err;
 
-	err = probe_user_read(&val, nip, sizeof(val));
+	err = copy_from_user_nofault(&val, nip, sizeof(val));
 	if (!err)
 		*inst = ppc_inst(val);
 
diff --git a/arch/powerpc/oprofile/backtrace.c b/arch/powerpc/oprofile/backtrace.c
index 6f347fa29f41..9db7ada79d10 100644
--- a/arch/powerpc/oprofile/backtrace.c
+++ b/arch/powerpc/oprofile/backtrace.c
@@ -33,7 +33,8 @@ static unsigned int user_getsp32(unsigned int sp, int is_first)
 	 * which means that we've done all that we can do from
 	 * interrupt context.
 	 */
-	if (probe_user_read(stack_frame, (void __user *)p, sizeof(stack_frame)))
+	if (copy_from_user_nofault(stack_frame, (void __user *)p,
+			sizeof(stack_frame)))
 		return 0;
 
 	if (!is_first)
@@ -51,7 +52,8 @@ static unsigned long user_getsp64(unsigned long sp, int is_first)
 {
 	unsigned long stack_frame[3];
 
-	if (probe_user_read(stack_frame, (void __user *)sp, sizeof(stack_frame)))
+	if (copy_from_user_nofault(stack_frame, (void __user *)sp,
+			sizeof(stack_frame)))
 		return 0;
 
 	if (!is_first)
diff --git a/arch/powerpc/perf/callchain_32.c b/arch/powerpc/perf/callchain_32.c
index f7d888d39cd3..542e68b8eae0 100644
--- a/arch/powerpc/perf/callchain_32.c
+++ b/arch/powerpc/perf/callchain_32.c
@@ -44,7 +44,7 @@ static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
 	    ((unsigned long)ptr & 3))
 		return -EFAULT;
 
-	rc = probe_user_read(ret, ptr, sizeof(*ret));
+	rc = copy_from_user_nofault(ret, ptr, sizeof(*ret));
 
 	if (IS_ENABLED(CONFIG_PPC64) && rc)
 		return read_user_stack_slow(ptr, ret, 4);
diff --git a/arch/powerpc/perf/callchain_64.c b/arch/powerpc/perf/callchain_64.c
index 814d1c2c2b9c..fa2a1b83b9b0 100644
--- a/arch/powerpc/perf/callchain_64.c
+++ b/arch/powerpc/perf/callchain_64.c
@@ -50,7 +50,7 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
 	    ((unsigned long)ptr & 7))
 		return -EFAULT;
 
-	if (!probe_user_read(ret, ptr, sizeof(*ret)))
+	if (!copy_from_user_nofault(ret, ptr, sizeof(*ret)))
 		return 0;
 
 	return read_user_stack_slow(ptr, ret, 8);
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index efe97ff82557..cd6a742ac6ef 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -426,7 +426,8 @@ static __u64 power_pmu_bhrb_to(u64 addr)
 	}
 
 	/* Userspace: need copy instruction here then translate it */
-	if (probe_user_read(&instr, (unsigned int __user *)addr, sizeof(instr)))
+	if (copy_from_user_nofault(&instr, (unsigned int __user *)addr,
+			sizeof(instr)))
 		return 0;
 
 	target = branch_target((struct ppc_inst *)&instr);
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 4a8874bc1057..73fa37ca40ef 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1066,8 +1066,8 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
 
 	if (is_in_pci_mem_space(addr)) {
 		if (user_mode(regs))
-			ret = probe_user_read(&inst, (void __user *)regs->nip,
-					      sizeof(inst));
+			ret = copy_from_user_nofault(&inst,
+					(void __user *)regs->nip, sizeof(inst));
 		else
 			ret = probe_kernel_address((void *)regs->nip, inst);
 
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 70a3d9cd9113..bef48da242cc 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -306,8 +306,8 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
 long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
 long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);
 
-extern long probe_user_read(void *dst, const void __user *src, size_t size);
-extern long notrace probe_user_write(void __user *dst, const void *src,
+long copy_from_user_nofault(void *dst, const void __user *src, size_t size);
+long notrace copy_to_user_nofault(void __user *dst, const void *src,
 		size_t size);
 
 long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 204afc12425f..dc05626979b8 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -141,7 +141,7 @@ bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
 {
 	int ret;
 
-	ret = probe_user_read(dst, unsafe_ptr, size);
+	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
 	if (unlikely(ret < 0))
 		memset(dst, 0, size);
 	return ret;
@@ -326,7 +326,7 @@ BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
 	if (unlikely(!nmi_uaccess_okay()))
 		return -EPERM;
 
-	return probe_user_write(unsafe_ptr, src, size);
+	return copy_to_user_nofault(unsafe_ptr, src, size);
 }
 
 static const struct bpf_func_proto bpf_probe_write_user_proto = {
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 841c74863ff8..aefb6065b508 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1290,7 +1290,7 @@ probe_mem_read_user(void *dest, void *src, size_t size)
 {
 	const void __user *uaddr =  (__force const void __user *)src;
 
-	return probe_user_read(dest, uaddr, size);
+	return copy_from_user_nofault(dest, uaddr, size);
 }
 
 static nokprobe_inline int
diff --git a/mm/maccess.c b/mm/maccess.c
index cc5d8c6233c0..f98ff91e32c6 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -194,7 +194,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
 #endif /* HAVE_GET_KERNEL_NOFAULT */
 
 /**
- * probe_user_read(): safely attempt to read from a user-space location
+ * copy_from_user_nofault(): safely attempt to read from a user-space location
  * @dst: pointer to the buffer that shall take the data
  * @src: address to read from. This must be a user address.
  * @size: size of the data chunk
@@ -202,7 +202,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
  * Safely read from user address @src to the buffer at @dst. If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long probe_user_read(void *dst, const void __user *src, size_t size)
+long copy_from_user_nofault(void *dst, const void __user *src, size_t size)
 {
 	long ret = -EFAULT;
 	mm_segment_t old_fs = get_fs();
@@ -219,10 +219,10 @@ long probe_user_read(void *dst, const void __user *src, size_t size)
 		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(probe_user_read);
+EXPORT_SYMBOL_GPL(copy_from_user_nofault);
 
 /**
- * probe_user_write(): safely attempt to write to a user-space location
+ * copy_to_user_nofault(): safely attempt to write to a user-space location
  * @dst: address to write to
  * @src: pointer to the data that shall be written
  * @size: size of the data chunk
@@ -230,7 +230,7 @@ EXPORT_SYMBOL_GPL(probe_user_read);
  * Safely write to address @dst from the buffer at @src.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long probe_user_write(void __user *dst, const void *src, size_t size)
+long copy_to_user_nofault(void __user *dst, const void *src, size_t size)
 {
 	long ret = -EFAULT;
 	mm_segment_t old_fs = get_fs();
@@ -247,7 +247,7 @@ long probe_user_write(void __user *dst, const void *src, size_t size)
 		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(probe_user_write);
+EXPORT_SYMBOL_GPL(copy_to_user_nofault);
 
 /**
  * strncpy_from_user_nofault: - Copy a NUL terminated string from unsafe user
-- 
cgit v1.2.3-59-g8ed1b


From 25f12ae45fc1931a1dce3cc59f9989a9d87834b0 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Wed, 17 Jun 2020 09:37:55 +0200
Subject: maccess: rename probe_kernel_address to get_kernel_nofault

Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.

Also switch the argument order around, so that it acts and looks
like get_user().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/arm/kernel/traps.c             |  2 +-
 arch/arm/mm/alignment.c             |  4 ++--
 arch/arm64/kernel/traps.c           |  2 +-
 arch/ia64/include/asm/sections.h    |  2 +-
 arch/parisc/kernel/process.c        |  2 +-
 arch/powerpc/include/asm/sections.h |  2 +-
 arch/powerpc/kernel/kgdb.c          |  2 +-
 arch/powerpc/kernel/kprobes.c       |  2 +-
 arch/powerpc/kernel/process.c       |  2 +-
 arch/powerpc/sysdev/fsl_pci.c       |  2 +-
 arch/riscv/kernel/kgdb.c            |  4 ++--
 arch/riscv/kernel/traps.c           |  4 ++--
 arch/s390/mm/fault.c                |  2 +-
 arch/sh/kernel/traps.c              |  2 +-
 arch/x86/kernel/probe_roms.c        | 20 ++++++++++----------
 arch/x86/kernel/traps.c             |  2 +-
 arch/x86/mm/fault.c                 |  6 +++---
 arch/x86/pci/pcbios.c               |  2 +-
 include/linux/uaccess.h             | 10 +++++-----
 lib/test_lockup.c                   |  6 +++---
 20 files changed, 40 insertions(+), 40 deletions(-)

(limited to 'include')

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 65a3b1e75480..49ce15c3612d 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -396,7 +396,7 @@ int is_valid_bugaddr(unsigned long pc)
 	u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
 #endif
 
-	if (probe_kernel_address((unsigned *)pc, bkpt))
+	if (get_kernel_nofault(bkpt, (unsigned *)pc))
 		return 0;
 
 	return bkpt == insn;
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 84718eddae60..81a627e6e1c5 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -774,7 +774,7 @@ static int alignment_get_arm(struct pt_regs *regs, u32 *ip, u32 *inst)
 	if (user_mode(regs))
 		fault = get_user(instr, ip);
 	else
-		fault = probe_kernel_address(ip, instr);
+		fault = get_kernel_nofault(instr, ip);
 
 	*inst = __mem_to_opcode_arm(instr);
 
@@ -789,7 +789,7 @@ static int alignment_get_thumb(struct pt_regs *regs, u16 *ip, u16 *inst)
 	if (user_mode(regs))
 		fault = get_user(instr, ip);
 	else
-		fault = probe_kernel_address(ip, instr);
+		fault = get_kernel_nofault(instr, ip);
 
 	*inst = __mem_to_opcode_thumb16(instr);
 
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 50cc30acf106..227b2d9bae3d 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -376,7 +376,7 @@ static int call_undef_hook(struct pt_regs *regs)
 
 	if (!user_mode(regs)) {
 		__le32 instr_le;
-		if (probe_kernel_address((__force __le32 *)pc, instr_le))
+		if (get_kernel_nofault(instr_le, (__force __le32 *)pc))
 			goto exit;
 		instr = le32_to_cpu(instr_le);
 	} else if (compat_thumb_mode(regs)) {
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index cea15f2dd38d..ad4fc06e5f4b 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -35,7 +35,7 @@ static inline void *dereference_function_descriptor(void *ptr)
 	struct fdesc *desc = ptr;
 	void *p;
 
-	if (!probe_kernel_address(&desc->ip, p))
+	if (!get_kernel_nofault(p, &desc->ip))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 230a6422b99f..6c435dbccca0 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -293,7 +293,7 @@ void *dereference_function_descriptor(void *ptr)
 	Elf64_Fdesc *desc = ptr;
 	void *p;
 
-	if (!probe_kernel_address(&desc->addr, p))
+	if (!get_kernel_nofault(p, &desc->addr))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index d19871763ed4..bd311616fca8 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -85,7 +85,7 @@ static inline void *dereference_function_descriptor(void *ptr)
 	struct ppc64_opd_entry *desc = ptr;
 	void *p;
 
-	if (!probe_kernel_address(&desc->funcaddr, p))
+	if (!get_kernel_nofault(p, &desc->funcaddr))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 652b2852bea3..e14a1862a3ca 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -421,7 +421,7 @@ int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
 	unsigned int instr;
 	struct ppc_inst *addr = (struct ppc_inst *)bpt->bpt_addr;
 
-	err = probe_kernel_address(addr, instr);
+	err = get_kernel_nofault(instr, addr);
 	if (err)
 		return err;
 
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 6f96f65ebfe8..9cc792a3a6a9 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -289,7 +289,7 @@ int kprobe_handler(struct pt_regs *regs)
 	if (!p) {
 		unsigned int instr;
 
-		if (probe_kernel_address(addr, instr))
+		if (get_kernel_nofault(instr, addr))
 			goto no_kprobe;
 
 		if (instr != BREAKPOINT_INSTRUCTION) {
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d4d0d1048500..30955a0c32d0 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1271,7 +1271,7 @@ static void show_instructions(struct pt_regs *regs)
 #endif
 
 		if (!__kernel_text_address(pc) ||
-		    probe_kernel_address((const void *)pc, instr)) {
+		    get_kernel_nofault(instr, (const void *)pc)) {
 			pr_cont("XXXXXXXX ");
 		} else {
 			if (regs->nip == pc)
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 73fa37ca40ef..040b9d01c079 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1069,7 +1069,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
 			ret = copy_from_user_nofault(&inst,
 					(void __user *)regs->nip, sizeof(inst));
 		else
-			ret = probe_kernel_address((void *)regs->nip, inst);
+			ret = get_kernel_nofault(inst, (void *)regs->nip);
 
 		if (!ret && mcheck_handle_load(regs, inst)) {
 			regs->nip += 4;
diff --git a/arch/riscv/kernel/kgdb.c b/arch/riscv/kernel/kgdb.c
index a21fb21883e7..c3275f42d1ac 100644
--- a/arch/riscv/kernel/kgdb.c
+++ b/arch/riscv/kernel/kgdb.c
@@ -62,7 +62,7 @@ int get_step_address(struct pt_regs *regs, unsigned long *next_addr)
 	unsigned int rs1_num, rs2_num;
 	int op_code;
 
-	if (probe_kernel_address((void *)pc, op_code))
+	if (get_kernel_nofault(op_code, (void *)pc))
 		return -EINVAL;
 	if ((op_code & __INSN_LENGTH_MASK) != __INSN_LENGTH_GE_32) {
 		if (is_c_jalr_insn(op_code) || is_c_jr_insn(op_code)) {
@@ -146,7 +146,7 @@ int do_single_step(struct pt_regs *regs)
 		return error;
 
 	/* Store the op code in the stepped address */
-	error = probe_kernel_address((void *)addr, stepped_opcode);
+	error = get_kernel_nofault(stepped_opcode, (void *)addr);
 	if (error)
 		return error;
 
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index ecec1778e3a4..7d95cce5e47c 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -137,7 +137,7 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
 {
 	bug_insn_t insn;
 
-	if (probe_kernel_address((bug_insn_t *)pc, insn))
+	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
 		return 0;
 
 	return GET_INSN_LENGTH(insn);
@@ -165,7 +165,7 @@ int is_valid_bugaddr(unsigned long pc)
 
 	if (pc < VMALLOC_START)
 		return 0;
-	if (probe_kernel_address((bug_insn_t *)pc, insn))
+	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
 		return 0;
 	if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
 		return (insn == __BUG_INSN_32);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 6a24751557f0..d53c2e2ea1fd 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -105,7 +105,7 @@ static int bad_address(void *p)
 {
 	unsigned long dummy;
 
-	return probe_kernel_address((unsigned long *)p, dummy);
+	return get_kernel_nofault(dummy, (unsigned long *)p);
 }
 
 static void dump_pagetable(unsigned long asce, unsigned long address)
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index a33025451fcd..9c3d32b80038 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -118,7 +118,7 @@ int is_valid_bugaddr(unsigned long addr)
 
 	if (addr < PAGE_OFFSET)
 		return 0;
-	if (probe_kernel_address((insn_size_t *)addr, opcode))
+	if (get_kernel_nofault(opcode, (insn_size_t *)addr))
 		return 0;
 	if (opcode == TRAPA_BUG_OPCODE)
 		return 1;
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index ee0286390a4c..65b0dd2bf25c 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -99,7 +99,7 @@ static bool probe_list(struct pci_dev *pdev, unsigned short vendor,
 	unsigned short device;
 
 	do {
-		if (probe_kernel_address(rom_list, device) != 0)
+		if (get_kernel_nofault(device, rom_list) != 0)
 			device = 0;
 
 		if (device && match_id(pdev, vendor, device))
@@ -125,13 +125,13 @@ static struct resource *find_oprom(struct pci_dev *pdev)
 			break;
 
 		rom = isa_bus_to_virt(res->start);
-		if (probe_kernel_address(rom + 0x18, offset) != 0)
+		if (get_kernel_nofault(offset, rom + 0x18) != 0)
 			continue;
 
-		if (probe_kernel_address(rom + offset + 0x4, vendor) != 0)
+		if (get_kernel_nofault(vendor, rom + offset + 0x4) != 0)
 			continue;
 
-		if (probe_kernel_address(rom + offset + 0x6, device) != 0)
+		if (get_kernel_nofault(device, rom + offset + 0x6) != 0)
 			continue;
 
 		if (match_id(pdev, vendor, device)) {
@@ -139,8 +139,8 @@ static struct resource *find_oprom(struct pci_dev *pdev)
 			break;
 		}
 
-		if (probe_kernel_address(rom + offset + 0x8, list) == 0 &&
-		    probe_kernel_address(rom + offset + 0xc, rev) == 0 &&
+		if (get_kernel_nofault(list, rom + offset + 0x8) == 0 &&
+		    get_kernel_nofault(rev, rom + offset + 0xc) == 0 &&
 		    rev >= 3 && list &&
 		    probe_list(pdev, vendor, rom + offset + list)) {
 			oprom = res;
@@ -183,14 +183,14 @@ static int __init romsignature(const unsigned char *rom)
 	const unsigned short * const ptr = (const unsigned short *)rom;
 	unsigned short sig;
 
-	return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
+	return get_kernel_nofault(sig, ptr) == 0 && sig == ROMSIGNATURE;
 }
 
 static int __init romchecksum(const unsigned char *rom, unsigned long length)
 {
 	unsigned char sum, c;
 
-	for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
+	for (sum = 0; length && get_kernel_nofault(c, rom++) == 0; length--)
 		sum += c;
 	return !length && !sum;
 }
@@ -211,7 +211,7 @@ void __init probe_roms(void)
 
 		video_rom_resource.start = start;
 
-		if (probe_kernel_address(rom + 2, c) != 0)
+		if (get_kernel_nofault(c, rom + 2) != 0)
 			continue;
 
 		/* 0 < length <= 0x7f * 512, historically */
@@ -249,7 +249,7 @@ void __init probe_roms(void)
 		if (!romsignature(rom))
 			continue;
 
-		if (probe_kernel_address(rom + 2, c) != 0)
+		if (get_kernel_nofault(c, rom + 2) != 0)
 			continue;
 
 		/* 0 < length <= 0x7f * 512, historically */
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 7003f2e7b163..f9727b96961f 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -91,7 +91,7 @@ int is_valid_bugaddr(unsigned long addr)
 	if (addr < TASK_SIZE_MAX)
 		return 0;
 
-	if (probe_kernel_address((unsigned short *)addr, ud))
+	if (get_kernel_nofault(ud, (unsigned short *)addr))
 		return 0;
 
 	return ud == INSN_UD0 || ud == INSN_UD2;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index e996aa3833b8..1ead568c0101 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -99,7 +99,7 @@ check_prefetch_opcode(struct pt_regs *regs, unsigned char *instr,
 		return !instr_lo || (instr_lo>>1) == 1;
 	case 0x00:
 		/* Prefetch instruction is 0x0F0D or 0x0F18 */
-		if (probe_kernel_address(instr, opcode))
+		if (get_kernel_nofault(opcode, instr))
 			return 0;
 
 		*prefetch = (instr_lo == 0xF) &&
@@ -133,7 +133,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
 	while (instr < max_instr) {
 		unsigned char opcode;
 
-		if (probe_kernel_address(instr, opcode))
+		if (get_kernel_nofault(opcode, instr))
 			break;
 
 		instr++;
@@ -301,7 +301,7 @@ static int bad_address(void *p)
 {
 	unsigned long dummy;
 
-	return probe_kernel_address((unsigned long *)p, dummy);
+	return get_kernel_nofault(dummy, (unsigned long *)p);
 }
 
 static void dump_pagetable(unsigned long address)
diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c
index 9c97d814125e..4f15280732ed 100644
--- a/arch/x86/pci/pcbios.c
+++ b/arch/x86/pci/pcbios.c
@@ -302,7 +302,7 @@ static const struct pci_raw_ops *__init pci_find_bios(void)
 	     check <= (union bios32 *) __va(0xffff0);
 	     ++check) {
 		long sig;
-		if (probe_kernel_address(&check->fields.signature, sig))
+		if (get_kernel_nofault(sig, &check->fields.signature))
 			continue;
 
 		if (check->fields.signature != BIOS32_SIGNATURE)
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index bef48da242cc..a508a3c08879 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -318,14 +318,14 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
 long strnlen_user_nofault(const void __user *unsafe_addr, long count);
 
 /**
- * probe_kernel_address(): safely attempt to read from a location
- * @addr: address to read from
- * @retval: read into this variable
+ * get_kernel_nofault(): safely attempt to read from a location
+ * @val: read into this variable
+ * @ptr: address to read from
  *
  * Returns 0 on success, or -EFAULT.
  */
-#define probe_kernel_address(addr, retval)		\
-	copy_from_kernel_nofault(&retval, addr, sizeof(retval))
+#define get_kernel_nofault(val, ptr)		\
+	copy_from_kernel_nofault(&(val), (ptr), sizeof(val))
 
 #ifndef user_access_begin
 #define user_access_begin(ptr,len) access_ok(ptr, len)
diff --git a/lib/test_lockup.c b/lib/test_lockup.c
index f258743a0d83..bd7c7ff39f6b 100644
--- a/lib/test_lockup.c
+++ b/lib/test_lockup.c
@@ -419,8 +419,8 @@ static bool test_kernel_ptr(unsigned long addr, int size)
 	/* should be at least readable kernel address */
 	if (access_ok(ptr, 1) ||
 	    access_ok(ptr + size - 1, 1) ||
-	    probe_kernel_address(ptr, buf) ||
-	    probe_kernel_address(ptr + size - 1, buf)) {
+	    get_kernel_nofault(buf, ptr) ||
+	    get_kernel_nofault(buf, ptr + size - 1)) {
 		pr_err("invalid kernel ptr: %#lx\n", addr);
 		return true;
 	}
@@ -437,7 +437,7 @@ static bool __maybe_unused test_magic(unsigned long addr, int offset,
 	if (!addr)
 		return false;
 
-	if (probe_kernel_address(ptr, magic) || magic != expected) {
+	if (get_kernel_nofault(magic, ptr) || magic != expected) {
 		pr_err("invalid magic at %#lx + %#x = %#x, expected %#x\n",
 		       addr, offset, magic, expected);
 		return true;
-- 
cgit v1.2.3-59-g8ed1b


From 0c389d89abc28edf70ae847ee2fa55acb267b826 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 18 Jun 2020 12:10:37 -0700
Subject: maccess: make get_kernel_nofault() check for minimal type
 compatibility

Now that we've renamed probe_kernel_address() to get_kernel_nofault()
and made it look and behave more in line with get_user(), some of the
subtle type behavior differences end up being more obvious and possibly
dangerous.

When you do

        get_user(val, user_ptr);

the type of the access comes from the "user_ptr" part, and the above
basically acts as

        val = *user_ptr;

by design (except, of course, for the fact that the actual dereference
is done with a user access).

Note how in the above case, the type of the end result comes from the
pointer argument, and then the value is cast to the type of 'val' as
part of the assignment.

So the type of the pointer is ultimately the more important type both
for the access itself.

But 'get_kernel_nofault()' may now _look_ similar, but it behaves very
differently.  When you do

        get_kernel_nofault(val, kernel_ptr);

it behaves like

        val = *(typeof(val) *)kernel_ptr;

except, of course, for the fact that the actual dereference is done with
exception handling so that a faulting access is suppressed and returned
as the error code.

But note how different the casting behavior of the two superficially
similar accesses are: one does the actual access in the size of the type
the pointer points to, while the other does the access in the size of
the target, and ignores the pointer type entirely.

Actually changing get_kernel_nofault() to act like get_user() is almost
certainly the right thing to do eventually, but in the meantime this
patch adds logit to at least verify that the pointer type is compatible
with the type of the result.

In many cases, this involves just casting the pointer to 'void *' to
make it obvious that the type of the pointer is not the important part.
It's not how 'get_user()' acts, but at least the behavioral difference
is now obvious and explicit.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/arm/kernel/traps.c             | 2 +-
 arch/ia64/include/asm/sections.h    | 2 +-
 arch/parisc/kernel/process.c        | 2 +-
 arch/powerpc/include/asm/sections.h | 2 +-
 arch/powerpc/kernel/kgdb.c          | 2 +-
 arch/x86/kernel/probe_roms.c        | 4 ++--
 include/linux/uaccess.h             | 6 ++++--
 7 files changed, 11 insertions(+), 9 deletions(-)

(limited to 'include')

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 49ce15c3612d..17d5a785df28 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -396,7 +396,7 @@ int is_valid_bugaddr(unsigned long pc)
 	u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
 #endif
 
-	if (get_kernel_nofault(bkpt, (unsigned *)pc))
+	if (get_kernel_nofault(bkpt, (void *)pc))
 		return 0;
 
 	return bkpt == insn;
diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index ad4fc06e5f4b..3a033d2008b3 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -35,7 +35,7 @@ static inline void *dereference_function_descriptor(void *ptr)
 	struct fdesc *desc = ptr;
 	void *p;
 
-	if (!get_kernel_nofault(p, &desc->ip))
+	if (!get_kernel_nofault(p, (void *)&desc->ip))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 6c435dbccca0..b7abb12edd3a 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -293,7 +293,7 @@ void *dereference_function_descriptor(void *ptr)
 	Elf64_Fdesc *desc = ptr;
 	void *p;
 
-	if (!get_kernel_nofault(p, &desc->addr))
+	if (!get_kernel_nofault(p, (void *)&desc->addr))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index bd311616fca8..324d7b298ec3 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -85,7 +85,7 @@ static inline void *dereference_function_descriptor(void *ptr)
 	struct ppc64_opd_entry *desc = ptr;
 	void *p;
 
-	if (!get_kernel_nofault(p, &desc->funcaddr))
+	if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
 		ptr = p;
 	return ptr;
 }
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index e14a1862a3ca..409080208a6c 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -421,7 +421,7 @@ int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
 	unsigned int instr;
 	struct ppc_inst *addr = (struct ppc_inst *)bpt->bpt_addr;
 
-	err = get_kernel_nofault(instr, addr);
+	err = get_kernel_nofault(instr, (unsigned *) addr);
 	if (err)
 		return err;
 
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index 65b0dd2bf25c..9e1def3744f2 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -94,7 +94,7 @@ static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short
 }
 
 static bool probe_list(struct pci_dev *pdev, unsigned short vendor,
-		       const unsigned char *rom_list)
+		       const void *rom_list)
 {
 	unsigned short device;
 
@@ -119,7 +119,7 @@ static struct resource *find_oprom(struct pci_dev *pdev)
 	for (i = 0; i < ARRAY_SIZE(adapter_rom_resources); i++) {
 		struct resource *res = &adapter_rom_resources[i];
 		unsigned short offset, vendor, device, list, rev;
-		const unsigned char *rom;
+		const void *rom;
 
 		if (res->end == 0)
 			break;
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index a508a3c08879..0a76ddc07d59 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -324,8 +324,10 @@ long strnlen_user_nofault(const void __user *unsafe_addr, long count);
  *
  * Returns 0 on success, or -EFAULT.
  */
-#define get_kernel_nofault(val, ptr)		\
-	copy_from_kernel_nofault(&(val), (ptr), sizeof(val))
+#define get_kernel_nofault(val, ptr) ({				\
+	const typeof(val) *__gk_ptr = (ptr);			\
+	copy_from_kernel_nofault(&(val), __gk_ptr, sizeof(val));\
+})
 
 #ifndef user_access_begin
 #define user_access_begin(ptr,len) access_ok(ptr, len)
-- 
cgit v1.2.3-59-g8ed1b