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authorLinus Torvalds <torvalds@linux-foundation.org>2015-12-16 19:57:24 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2015-12-16 19:57:24 +0100
commita5e90b1b075f89f084047628d4ef181aded0bbfb (patch)
treeda0010e547be7bf0f3b2bac9d7c74015e5e8662f /arch
parentMerge tag 'dmaengine-fix-4.4-rc6' of git://git.infradead.org/users/vkoul/slav... (diff)
parentARM: 8475/1: SWP emulation: Restore original *data when failed (diff)
downloadlinux-a5e90b1b075f89f084047628d4ef181aded0bbfb.tar.xz
linux-a5e90b1b075f89f084047628d4ef181aded0bbfb.zip
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King: "Further ARM fixes: - Anson Huang noticed that we were corrupting a register we shouldn't be during suspend on some CPUs. - Shengjiu Wang spotted a bug in the 'swp' instruction emulation. - Will Deacon fixed a bug in the ASID allocator. - Laura Abbott fixed the kernel permission protection to apply to all threads running in the system. - I've fixed two bugs with the domain access control register handling, one to do with printing an appropriate value at oops time, and the other to further fix the uaccess_with_memcpy code" * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: 8475/1: SWP emulation: Restore original *data when failed ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN ARM: report proper DACR value in oops dumps ARM: 8464/1: Update all mm structures with section adjustments ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/uaccess.h4
-rw-r--r--arch/arm/kernel/process.c33
-rw-r--r--arch/arm/kernel/swp_emulate.c6
-rw-r--r--arch/arm/lib/uaccess_with_memcpy.c29
-rw-r--r--arch/arm/mm/context.c38
-rw-r--r--arch/arm/mm/init.c92
-rw-r--r--arch/arm/mm/proc-v7.S4
7 files changed, 138 insertions, 68 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 8cc85a4ebec2..35c9db857ebe 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -510,10 +510,14 @@ __copy_to_user_std(void __user *to, const void *from, unsigned long n);
static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
+#ifndef CONFIG_UACCESS_WITH_MEMCPY
unsigned int __ua_flags = uaccess_save_and_enable();
n = arm_copy_to_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
+#else
+ return arm_copy_to_user(to, from, n);
+#endif
}
extern unsigned long __must_check
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 7a7c4cea5523..4adfb46e3ee9 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -95,6 +95,22 @@ void __show_regs(struct pt_regs *regs)
{
unsigned long flags;
char buf[64];
+#ifndef CONFIG_CPU_V7M
+ unsigned int domain;
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+ /*
+ * Get the domain register for the parent context. In user
+ * mode, we don't save the DACR, so lets use what it should
+ * be. For other modes, we place it after the pt_regs struct.
+ */
+ if (user_mode(regs))
+ domain = DACR_UACCESS_ENABLE;
+ else
+ domain = *(unsigned int *)(regs + 1);
+#else
+ domain = get_domain();
+#endif
+#endif
show_regs_print_info(KERN_DEFAULT);
@@ -123,21 +139,8 @@ void __show_regs(struct pt_regs *regs)
#ifndef CONFIG_CPU_V7M
{
- unsigned int domain = get_domain();
const char *segment;
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- /*
- * Get the domain register for the parent context. In user
- * mode, we don't save the DACR, so lets use what it should
- * be. For other modes, we place it after the pt_regs struct.
- */
- if (user_mode(regs))
- domain = DACR_UACCESS_ENABLE;
- else
- domain = *(unsigned int *)(regs + 1);
-#endif
-
if ((domain & domain_mask(DOMAIN_USER)) ==
domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
segment = "none";
@@ -163,11 +166,11 @@ void __show_regs(struct pt_regs *regs)
buf[0] = '\0';
#ifdef CONFIG_CPU_CP15_MMU
{
- unsigned int transbase, dac = get_domain();
+ unsigned int transbase;
asm("mrc p15, 0, %0, c2, c0\n\t"
: "=r" (transbase));
snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
- transbase, dac);
+ transbase, domain);
}
#endif
asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index 5b26e7efa9ea..c3fe769d7558 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -36,10 +36,10 @@
*/
#define __user_swpX_asm(data, addr, res, temp, B) \
__asm__ __volatile__( \
- " mov %2, %1\n" \
- "0: ldrex"B" %1, [%3]\n" \
- "1: strex"B" %0, %2, [%3]\n" \
+ "0: ldrex"B" %2, [%3]\n" \
+ "1: strex"B" %0, %1, [%3]\n" \
" cmp %0, #0\n" \
+ " moveq %1, %2\n" \
" movne %0, %4\n" \
"2:\n" \
" .section .text.fixup,\"ax\"\n" \
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index d72b90905132..588bbc288396 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -88,6 +88,7 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
static unsigned long noinline
__copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
{
+ unsigned long ua_flags;
int atomic;
if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
@@ -118,7 +119,9 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
if (tocopy > n)
tocopy = n;
+ ua_flags = uaccess_save_and_enable();
memcpy((void *)to, from, tocopy);
+ uaccess_restore(ua_flags);
to += tocopy;
from += tocopy;
n -= tocopy;
@@ -145,14 +148,21 @@ arm_copy_to_user(void __user *to, const void *from, unsigned long n)
* With frame pointer disabled, tail call optimization kicks in
* as well making this test almost invisible.
*/
- if (n < 64)
- return __copy_to_user_std(to, from, n);
- return __copy_to_user_memcpy(to, from, n);
+ if (n < 64) {
+ unsigned long ua_flags = uaccess_save_and_enable();
+ n = __copy_to_user_std(to, from, n);
+ uaccess_restore(ua_flags);
+ } else {
+ n = __copy_to_user_memcpy(to, from, n);
+ }
+ return n;
}
static unsigned long noinline
__clear_user_memset(void __user *addr, unsigned long n)
{
+ unsigned long ua_flags;
+
if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
memset((void *)addr, 0, n);
return 0;
@@ -175,7 +185,9 @@ __clear_user_memset(void __user *addr, unsigned long n)
if (tocopy > n)
tocopy = n;
+ ua_flags = uaccess_save_and_enable();
memset((void *)addr, 0, tocopy);
+ uaccess_restore(ua_flags);
addr += tocopy;
n -= tocopy;
@@ -193,9 +205,14 @@ out:
unsigned long arm_clear_user(void __user *addr, unsigned long n)
{
/* See rational for this in __copy_to_user() above. */
- if (n < 64)
- return __clear_user_std(addr, n);
- return __clear_user_memset(addr, n);
+ if (n < 64) {
+ unsigned long ua_flags = uaccess_save_and_enable();
+ n = __clear_user_std(addr, n);
+ uaccess_restore(ua_flags);
+ } else {
+ n = __clear_user_memset(addr, n);
+ }
+ return n;
}
#if 0
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 845769e41332..c8c8b9ed02e0 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -165,13 +165,28 @@ static void flush_context(unsigned int cpu)
__flush_icache_all();
}
-static int is_reserved_asid(u64 asid)
+static bool check_update_reserved_asid(u64 asid, u64 newasid)
{
int cpu;
- for_each_possible_cpu(cpu)
- if (per_cpu(reserved_asids, cpu) == asid)
- return 1;
- return 0;
+ bool hit = false;
+
+ /*
+ * Iterate over the set of reserved ASIDs looking for a match.
+ * If we find one, then we can update our mm to use newasid
+ * (i.e. the same ASID in the current generation) but we can't
+ * exit the loop early, since we need to ensure that all copies
+ * of the old ASID are updated to reflect the mm. Failure to do
+ * so could result in us missing the reserved ASID in a future
+ * generation.
+ */
+ for_each_possible_cpu(cpu) {
+ if (per_cpu(reserved_asids, cpu) == asid) {
+ hit = true;
+ per_cpu(reserved_asids, cpu) = newasid;
+ }
+ }
+
+ return hit;
}
static u64 new_context(struct mm_struct *mm, unsigned int cpu)
@@ -181,12 +196,14 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
u64 generation = atomic64_read(&asid_generation);
if (asid != 0) {
+ u64 newasid = generation | (asid & ~ASID_MASK);
+
/*
* If our current ASID was active during a rollover, we
* can continue to use it and this was just a false alarm.
*/
- if (is_reserved_asid(asid))
- return generation | (asid & ~ASID_MASK);
+ if (check_update_reserved_asid(asid, newasid))
+ return newasid;
/*
* We had a valid ASID in a previous life, so try to re-use
@@ -194,7 +211,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
*/
asid &= ~ASID_MASK;
if (!__test_and_set_bit(asid, asid_map))
- goto bump_gen;
+ return newasid;
}
/*
@@ -216,11 +233,8 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu)
__set_bit(asid, asid_map);
cur_idx = asid;
-
-bump_gen:
- asid |= generation;
cpumask_clear(mm_cpumask(mm));
- return asid;
+ return asid | generation;
}
void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 8a63b4cdc0f2..7f8cd1b3557f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -22,6 +22,7 @@
#include <linux/memblock.h>
#include <linux/dma-contiguous.h>
#include <linux/sizes.h>
+#include <linux/stop_machine.h>
#include <asm/cp15.h>
#include <asm/mach-types.h>
@@ -627,12 +628,10 @@ static struct section_perm ro_perms[] = {
* safe to be called with preemption disabled, as under stop_machine().
*/
static inline void section_update(unsigned long addr, pmdval_t mask,
- pmdval_t prot)
+ pmdval_t prot, struct mm_struct *mm)
{
- struct mm_struct *mm;
pmd_t *pmd;
- mm = current->active_mm;
pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
#ifdef CONFIG_ARM_LPAE
@@ -656,49 +655,82 @@ static inline bool arch_has_strict_perms(void)
return !!(get_cr() & CR_XP);
}
-#define set_section_perms(perms, field) { \
- size_t i; \
- unsigned long addr; \
- \
- if (!arch_has_strict_perms()) \
- return; \
- \
- for (i = 0; i < ARRAY_SIZE(perms); i++) { \
- if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) || \
- !IS_ALIGNED(perms[i].end, SECTION_SIZE)) { \
- pr_err("BUG: section %lx-%lx not aligned to %lx\n", \
- perms[i].start, perms[i].end, \
- SECTION_SIZE); \
- continue; \
- } \
- \
- for (addr = perms[i].start; \
- addr < perms[i].end; \
- addr += SECTION_SIZE) \
- section_update(addr, perms[i].mask, \
- perms[i].field); \
- } \
+void set_section_perms(struct section_perm *perms, int n, bool set,
+ struct mm_struct *mm)
+{
+ size_t i;
+ unsigned long addr;
+
+ if (!arch_has_strict_perms())
+ return;
+
+ for (i = 0; i < n; i++) {
+ if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
+ !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
+ pr_err("BUG: section %lx-%lx not aligned to %lx\n",
+ perms[i].start, perms[i].end,
+ SECTION_SIZE);
+ continue;
+ }
+
+ for (addr = perms[i].start;
+ addr < perms[i].end;
+ addr += SECTION_SIZE)
+ section_update(addr, perms[i].mask,
+ set ? perms[i].prot : perms[i].clear, mm);
+ }
+
}
-static inline void fix_kernmem_perms(void)
+static void update_sections_early(struct section_perm perms[], int n)
{
- set_section_perms(nx_perms, prot);
+ struct task_struct *t, *s;
+
+ read_lock(&tasklist_lock);
+ for_each_process(t) {
+ if (t->flags & PF_KTHREAD)
+ continue;
+ for_each_thread(t, s)
+ set_section_perms(perms, n, true, s->mm);
+ }
+ read_unlock(&tasklist_lock);
+ set_section_perms(perms, n, true, current->active_mm);
+ set_section_perms(perms, n, true, &init_mm);
+}
+
+int __fix_kernmem_perms(void *unused)
+{
+ update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
+ return 0;
+}
+
+void fix_kernmem_perms(void)
+{
+ stop_machine(__fix_kernmem_perms, NULL, NULL);
}
#ifdef CONFIG_DEBUG_RODATA
+int __mark_rodata_ro(void *unused)
+{
+ update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
+ return 0;
+}
+
void mark_rodata_ro(void)
{
- set_section_perms(ro_perms, prot);
+ stop_machine(__mark_rodata_ro, NULL, NULL);
}
void set_kernel_text_rw(void)
{
- set_section_perms(ro_perms, clear);
+ set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
+ current->active_mm);
}
void set_kernel_text_ro(void)
{
- set_section_perms(ro_perms, prot);
+ set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
+ current->active_mm);
}
#endif /* CONFIG_DEBUG_RODATA */
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index de2b246fed38..8e1ea433c3f1 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -95,7 +95,7 @@ ENDPROC(cpu_v7_dcache_clean_area)
.equ cpu_v7_suspend_size, 4 * 9
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7_do_suspend)
- stmfd sp!, {r4 - r10, lr}
+ stmfd sp!, {r4 - r11, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
@@ -112,7 +112,7 @@ ENTRY(cpu_v7_do_suspend)
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
stmia r0, {r5 - r11}
- ldmfd sp!, {r4 - r10, pc}
+ ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_v7_do_suspend)
ENTRY(cpu_v7_do_resume)