[PATCH 2/3] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault

From: Christoph Hellwig
Date: Wed Jun 17 2020 - 03:38:20 EST


Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
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(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 7bb7faf84490ec..d4d0d10485003d 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 3cb0c9843d01da..e738ea6521927f 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 6c7a20af9fd673..9cc17eb62462a6 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 6f347fa29f41ef..9db7ada79d10d4 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 f7d888d39cd3a9..542e68b8eae0b1 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 814d1c2c2b9cf0..fa2a1b83b9b0e7 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 efe97ff82557d0..cd6a742ac6ef5d 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 4a8874bc10574a..73fa37ca40ef95 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 70a3d9cd9113f8..bef48da242cc2c 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 204afc12425fd7..dc05626979b8f8 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 841c74863ff896..aefb6065b508de 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 cc5d8c6233c05a..f98ff91e32c6df 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
--
2.26.2