From: Arnd Bergmann <arnd@arndb.de>

The __range_not_ok() helper is an x86 (and sparc64) specific interface
that does roughly the same thing as __access_ok(), but with different
calling conventions.

Change this to use the normal interface in order for consistency as we
clean up all access_ok() implementations.

This changes the limit from TASK_SIZE to TASK_SIZE_MAX, which Al points
out is the right thing do do here anyway.

The callers have to use __access_ok() instead of the normal access_ok()
though, because on x86 that contains a WARN_ON_IN_IRQ() check that cannot
be used inside of NMI context while tracing.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@zeniv-ca.linux.org.uk/ (local)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/events/core.c         |  2 +-
 arch/x86/include/asm/uaccess.h | 10 ++++++----
 arch/x86/kernel/dumpstack.c    |  2 +-
 arch/x86/kernel/stacktrace.c   |  2 +-
 arch/x86/lib/usercopy.c        |  2 +-
 5 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index e686c5e0537b..eef816fc216d 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c

@@ -2794,7 +2794,7 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 static inline int
 valid_user_frame(const void __user *fp, unsigned long size)
 {
-	return (__range_not_ok(fp, size, TASK_SIZE) == 0);
+	return __access_ok(fp, size);
 }

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 53de044e5654..da534fb7b5c6 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c

@@ -85,7 +85,7 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src,
 	 * Make sure userspace isn't trying to trick us into dumping kernel
 	 * memory by pointing the userspace instruction pointer at it.
 	 */
-	if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX))
+	if (!__access_ok((void __user *)src, nbytes))
 		return -EINVAL;

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 15b058eefc4e..ee117fcf46ed 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c

@@ -90,7 +90,7 @@ copy_stack_frame(const struct stack_frame_user __user *fp,
 {
 	int ret;
 
-	if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE))
+	if (!__access_ok(fp, sizeof(*frame)))
 		return 0;