On Thu, May 28, 2020 at 3:49 PM Qian Cai <cai@xxxxxx> wrote:
>
> On Tue, May 12, 2020 at 05:33:20PM +0200, 'Andrey Konovalov' via kasan-dev wrote:
> > The kasan_report() functions belongs to report.c, as it's a common
> > functions that does error reporting.
> >
> > Reported-by: Leon Romanovsky <leon@xxxxxxxxxx>
> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
>
> Today's linux-next produced this with Clang 11.
>
> mm/kasan/report.o: warning: objtool: kasan_report()+0x8a: call to __stack_chk_fail() with UACCESS enabled
>
> kasan_report at mm/kasan/report.c:536
Hm, the first patch in the series ("kasan: consistently disable
debugging features") disables stack protector for kasan files. Is that
patch in linux-next?
>
> > ---
> > mm/kasan/common.c | 19 -------------------
> > mm/kasan/report.c | 22 ++++++++++++++++++++--
> > 2 files changed, 20 insertions(+), 21 deletions(-)
> >
> > diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> > index 2906358e42f0..757d4074fe28 100644
> > --- a/mm/kasan/common.c
> > +++ b/mm/kasan/common.c
> > @@ -33,7 +33,6 @@
> > #include <linux/types.h>
> > #include <linux/vmalloc.h>
> > #include <linux/bug.h>
> > -#include <linux/uaccess.h>
> >
> > #include <asm/cacheflush.h>
> > #include <asm/tlbflush.h>
> > @@ -613,24 +612,6 @@ void kasan_free_shadow(const struct vm_struct *vm)
> > }
> > #endif
> >
> > -extern void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip);
> > -extern bool report_enabled(void);
> > -
> > -bool kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip)
> > -{
> > - unsigned long flags = user_access_save();
> > - bool ret = false;
> > -
> > - if (likely(report_enabled())) {
> > - __kasan_report(addr, size, is_write, ip);
> > - ret = true;
> > - }
> > -
> > - user_access_restore(flags);
> > -
> > - return ret;
> > -}
> > -
> > #ifdef CONFIG_MEMORY_HOTPLUG
> > static bool shadow_mapped(unsigned long addr)
> > {
> > diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> > index 80f23c9da6b0..51ec45407a0b 100644
> > --- a/mm/kasan/report.c
> > +++ b/mm/kasan/report.c
> > @@ -29,6 +29,7 @@
> > #include <linux/kasan.h>
> > #include <linux/module.h>
> > #include <linux/sched/task_stack.h>
> > +#include <linux/uaccess.h>
> >
> > #include <asm/sections.h>
> >
> > @@ -454,7 +455,7 @@ static void print_shadow_for_address(const void *addr)
> > }
> > }
> >
> > -bool report_enabled(void)
> > +static bool report_enabled(void)
> > {
> > if (current->kasan_depth)
> > return false;
> > @@ -479,7 +480,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
> > end_report(&flags);
> > }
> >
> > -void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip)
> > +static void __kasan_report(unsigned long addr, size_t size, bool is_write,
> > + unsigned long ip)
> > {
> > struct kasan_access_info info;
> > void *tagged_addr;
> > @@ -518,6 +520,22 @@ void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned lon
> > end_report(&flags);
> > }
> >
> > +bool kasan_report(unsigned long addr, size_t size, bool is_write,
> > + unsigned long ip)
> > +{
> > + unsigned long flags = user_access_save();
> > + bool ret = false;
> > +
> > + if (likely(report_enabled())) {
> > + __kasan_report(addr, size, is_write, ip);
> > + ret = true;
> > + }
> > +
> > + user_access_restore(flags);
> > +
> > + return ret;
> > +}
> > +
> > #ifdef CONFIG_KASAN_INLINE
> > /*
> > * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high
> > --
> > 2.26.2.645.ge9eca65c58-goog
> >
> > --
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