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-rw-r--r--arch/s390/lib/uaccess.c105
1 files changed, 21 insertions, 84 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index 0267405ab7c6..e8f642446fed 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -16,6 +16,22 @@
#include <asm/mmu_context.h>
#include <asm/facility.h>
+#ifdef CONFIG_DEBUG_USER_ASCE
+void debug_user_asce(void)
+{
+ unsigned long cr1, cr7;
+
+ __ctl_store(cr1, 1, 1);
+ __ctl_store(cr7, 7, 7);
+ if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
+ return;
+ panic("incorrect ASCE on kernel exit\n"
+ "cr1: %016lx cr7: %016lx\n"
+ "kernel: %016llx user: %016llx\n",
+ cr1, cr7, S390_lowcore.kernel_asce, S390_lowcore.user_asce);
+}
+#endif /*CONFIG_DEBUG_USER_ASCE */
+
#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
static DEFINE_STATIC_KEY_FALSE(have_mvcos);
@@ -40,71 +56,10 @@ static inline int copy_with_mvcos(void)
}
#endif
-void set_fs(mm_segment_t fs)
-{
- current->thread.mm_segment = fs;
- if (fs == USER_DS) {
- __ctl_load(S390_lowcore.user_asce, 1, 1);
- clear_cpu_flag(CIF_ASCE_PRIMARY);
- } else {
- __ctl_load(S390_lowcore.kernel_asce, 1, 1);
- set_cpu_flag(CIF_ASCE_PRIMARY);
- }
- if (fs & 1) {
- if (fs == USER_DS_SACF)
- __ctl_load(S390_lowcore.user_asce, 7, 7);
- else
- __ctl_load(S390_lowcore.kernel_asce, 7, 7);
- set_cpu_flag(CIF_ASCE_SECONDARY);
- }
-}
-EXPORT_SYMBOL(set_fs);
-
-mm_segment_t enable_sacf_uaccess(void)
-{
- mm_segment_t old_fs;
- unsigned long asce, cr;
- unsigned long flags;
-
- old_fs = current->thread.mm_segment;
- if (old_fs & 1)
- return old_fs;
- /* protect against a concurrent page table upgrade */
- local_irq_save(flags);
- current->thread.mm_segment |= 1;
- asce = S390_lowcore.kernel_asce;
- if (likely(old_fs == USER_DS)) {
- __ctl_store(cr, 1, 1);
- if (cr != S390_lowcore.kernel_asce) {
- __ctl_load(S390_lowcore.kernel_asce, 1, 1);
- set_cpu_flag(CIF_ASCE_PRIMARY);
- }
- asce = S390_lowcore.user_asce;
- }
- __ctl_store(cr, 7, 7);
- if (cr != asce) {
- __ctl_load(asce, 7, 7);
- set_cpu_flag(CIF_ASCE_SECONDARY);
- }
- local_irq_restore(flags);
- return old_fs;
-}
-EXPORT_SYMBOL(enable_sacf_uaccess);
-
-void disable_sacf_uaccess(mm_segment_t old_fs)
-{
- current->thread.mm_segment = old_fs;
- if (old_fs == USER_DS && test_facility(27)) {
- __ctl_load(S390_lowcore.user_asce, 1, 1);
- clear_cpu_flag(CIF_ASCE_PRIMARY);
- }
-}
-EXPORT_SYMBOL(disable_sacf_uaccess);
-
static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
unsigned long size)
{
- register unsigned long reg0 asm("0") = 0x01UL;
+ register unsigned long reg0 asm("0") = 0x81UL;
unsigned long tmp1, tmp2;
tmp1 = -4096UL;
@@ -135,9 +90,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
unsigned long size)
{
unsigned long tmp1, tmp2;
- mm_segment_t old_fs;
- old_fs = enable_sacf_uaccess();
tmp1 = -256UL;
asm volatile(
" sacf 0\n"
@@ -164,7 +117,6 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
- disable_sacf_uaccess(old_fs);
return size;
}
@@ -179,7 +131,7 @@ EXPORT_SYMBOL(raw_copy_from_user);
static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
unsigned long size)
{
- register unsigned long reg0 asm("0") = 0x010000UL;
+ register unsigned long reg0 asm("0") = 0x810000UL;
unsigned long tmp1, tmp2;
tmp1 = -4096UL;
@@ -210,9 +162,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
unsigned long size)
{
unsigned long tmp1, tmp2;
- mm_segment_t old_fs;
- old_fs = enable_sacf_uaccess();
tmp1 = -256UL;
asm volatile(
" sacf 0\n"
@@ -239,7 +189,6 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
- disable_sacf_uaccess(old_fs);
return size;
}
@@ -254,7 +203,7 @@ EXPORT_SYMBOL(raw_copy_to_user);
static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
unsigned long size)
{
- register unsigned long reg0 asm("0") = 0x010001UL;
+ register unsigned long reg0 asm("0") = 0x810081UL;
unsigned long tmp1, tmp2;
tmp1 = -4096UL;
@@ -277,10 +226,8 @@ static inline unsigned long copy_in_user_mvcos(void __user *to, const void __use
static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
unsigned long size)
{
- mm_segment_t old_fs;
unsigned long tmp1;
- old_fs = enable_sacf_uaccess();
asm volatile(
" sacf 256\n"
" aghi %0,-1\n"
@@ -304,7 +251,6 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user
EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
: : "cc", "memory");
- disable_sacf_uaccess(old_fs);
return size;
}
@@ -318,7 +264,7 @@ EXPORT_SYMBOL(raw_copy_in_user);
static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
{
- register unsigned long reg0 asm("0") = 0x010000UL;
+ register unsigned long reg0 asm("0") = 0x810000UL;
unsigned long tmp1, tmp2;
tmp1 = -4096UL;
@@ -346,10 +292,8 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size
static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
{
- mm_segment_t old_fs;
unsigned long tmp1, tmp2;
- old_fs = enable_sacf_uaccess();
asm volatile(
" sacf 256\n"
" aghi %0,-1\n"
@@ -378,7 +322,6 @@ static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
- disable_sacf_uaccess(old_fs);
return size;
}
@@ -414,15 +357,9 @@ static inline unsigned long strnlen_user_srst(const char __user *src,
unsigned long __strnlen_user(const char __user *src, unsigned long size)
{
- mm_segment_t old_fs;
- unsigned long len;
-
if (unlikely(!size))
return 0;
- old_fs = enable_sacf_uaccess();
- len = strnlen_user_srst(src, size);
- disable_sacf_uaccess(old_fs);
- return len;
+ return strnlen_user_srst(src, size);
}
EXPORT_SYMBOL(__strnlen_user);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 06:55:23 +0300