2d4e33084f
* Mon May 04 2020 CKI@GitLab <cki-project@redhat.com> [5.7.0-0.rc4.1]
- v5.7-rc4 rebase
- Updated changelog for the release based on f66ed1ebbfde ("CKI@GitLab")
Resolves: rhbz#
Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
87 lines
3.3 KiB
Diff
87 lines
3.3 KiB
Diff
From e51d6f27ecbc5e6529ce27e8534c52ec77e89172 Mon Sep 17 00:00:00 2001
|
|
From: Masahiro Yamada <yamada.masahiro@socionext.com>
|
|
Date: Mon, 30 Sep 2019 14:59:25 +0900
|
|
Subject: [PATCH] ARM: fix __get_user_check() in case uaccess_* calls are not
|
|
inlined
|
|
|
|
KernelCI reports that bcm2835_defconfig is no longer booting since
|
|
commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING
|
|
forcibly"):
|
|
|
|
https://lkml.org/lkml/2019/9/26/825
|
|
|
|
I also received a regression report from Nicolas Saenz Julienne:
|
|
|
|
https://lkml.org/lkml/2019/9/27/263
|
|
|
|
This problem has cropped up on arch/arm/config/bcm2835_defconfig
|
|
because it enables CONFIG_CC_OPTIMIZE_FOR_SIZE. The compiler tends
|
|
to prefer not inlining functions with -Os. I was able to reproduce
|
|
it with other boards and defconfig files by manually enabling
|
|
CONFIG_CC_OPTIMIZE_FOR_SIZE.
|
|
|
|
The __get_user_check() specifically uses r0, r1, r2 registers.
|
|
So, uaccess_save_and_enable() and uaccess_restore() must be inlined
|
|
in order to avoid those registers being overwritten in the callees.
|
|
|
|
Prior to commit 9012d011660e ("compiler: allow all arches to enable
|
|
CONFIG_OPTIMIZE_INLINING"), the 'inline' marker was always enough for
|
|
inlining functions, except on x86.
|
|
|
|
Since that commit, all architectures can enable CONFIG_OPTIMIZE_INLINING.
|
|
So, __always_inline is now the only guaranteed way of forcible inlining.
|
|
|
|
I want to keep as much compiler's freedom as possible about the inlining
|
|
decision. So, I changed the function call order instead of adding
|
|
__always_inline around.
|
|
|
|
Call uaccess_save_and_enable() before assigning the __p ("r0"), and
|
|
uaccess_restore() after evacuating the __e ("r0").
|
|
|
|
Fixes: 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING")
|
|
Reported-by: "kernelci.org bot" <bot@kernelci.org>
|
|
Reported-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
|
|
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
|
|
Acked-by: Arnd Bergmann <arnd@arndb.de>
|
|
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
|
|
Tested-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
|
|
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
|
|
---
|
|
arch/arm/include/asm/uaccess.h | 8 +++++---
|
|
1 file changed, 5 insertions(+), 3 deletions(-)
|
|
|
|
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
|
|
index 98c6b91be4a8..60055827dddc 100644
|
|
--- a/arch/arm/include/asm/uaccess.h
|
|
+++ b/arch/arm/include/asm/uaccess.h
|
|
@@ -191,11 +191,12 @@ extern int __get_user_64t_4(void *);
|
|
#define __get_user_check(x, p) \
|
|
({ \
|
|
unsigned long __limit = current_thread_info()->addr_limit - 1; \
|
|
+ unsigned int __ua_flags = uaccess_save_and_enable(); \
|
|
register typeof(*(p)) __user *__p asm("r0") = (p); \
|
|
register __inttype(x) __r2 asm("r2"); \
|
|
register unsigned long __l asm("r1") = __limit; \
|
|
register int __e asm("r0"); \
|
|
- unsigned int __ua_flags = uaccess_save_and_enable(); \
|
|
+ unsigned int __err; \
|
|
switch (sizeof(*(__p))) { \
|
|
case 1: \
|
|
if (sizeof((x)) >= 8) \
|
|
@@ -223,9 +224,10 @@ extern int __get_user_64t_4(void *);
|
|
break; \
|
|
default: __e = __get_user_bad(); break; \
|
|
} \
|
|
- uaccess_restore(__ua_flags); \
|
|
+ __err = __e; \
|
|
x = (typeof(*(p))) __r2; \
|
|
- __e; \
|
|
+ uaccess_restore(__ua_flags); \
|
|
+ __err; \
|
|
})
|
|
|
|
#define get_user(x, p) \
|
|
--
|
|
2.26.2
|
|
|