diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0215-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0215-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0215-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch b/target/linux/brcm2708/patches-4.4/0215-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch new file mode 100644 index 0000000000..0511407426 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0215-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch @@ -0,0 +1,53 @@ +From 250a9cb281e520a1c22ff9dd86d2fb44fddb4fe9 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Tue, 29 Mar 2016 15:32:30 +0100 +Subject: [PATCH 215/304] copy_from_user: CPU_SW_DOMAIN_PAN compatibility + +The downstream copy_from_user acceleration must also play nice with +CONFIG_CPU_SW_DOMAIN_PAN. + +See: https://github.com/raspberrypi/linux/issues/1381 + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + arch/arm/lib/uaccess_with_memcpy.c | 14 +++++++++++--- + 1 file changed, 11 insertions(+), 3 deletions(-) + +--- a/arch/arm/lib/uaccess_with_memcpy.c ++++ b/arch/arm/lib/uaccess_with_memcpy.c +@@ -186,6 +186,7 @@ out: + unsigned long noinline + __copy_from_user_memcpy(void *to, const void __user *from, unsigned long n) + { ++ unsigned long ua_flags; + int atomic; + + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) { +@@ -217,7 +218,9 @@ __copy_from_user_memcpy(void *to, const + if (tocopy > n) + tocopy = n; + ++ ua_flags = uaccess_save_and_enable(); + memcpy(to, (const void *)from, tocopy); ++ uaccess_restore(ua_flags); + to += tocopy; + from += tocopy; + n -= tocopy; +@@ -261,9 +264,14 @@ arm_copy_from_user(void *to, const void + * With frame pointer disabled, tail call optimization kicks in + * as well making this test almost invisible. + */ +- if (n < COPY_FROM_USER_THRESHOLD) +- return __copy_from_user_std(to, from, n); +- return __copy_from_user_memcpy(to, from, n); ++ if (n < COPY_TO_USER_THRESHOLD) { ++ unsigned long ua_flags = uaccess_save_and_enable(); ++ n = __copy_from_user_std(to, from, n); ++ uaccess_restore(ua_flags); ++ } else { ++ n = __copy_from_user_memcpy(to, from, n); ++ } ++ return n; + } + + static unsigned long noinline |