On Wed, Feb 16, 2022 at 02:13:19PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > 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@xxxxxxxxxxxxxxxxxx> > Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@xxxxxxxxxxxxxxxxxxxxx/ > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > 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); > } valid_user_frame just need to go away and the following __get_user calls replaced with normal get_user ones. > 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; This one is not needed at all as copy_from_user_nmi already checks the access range. > 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; Just switch the __get_user calls below to get_user instead.
