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-rw-r--r--arch/s390/mm/cmm.c1
-rw-r--r--arch/s390/mm/dump_pagetables.c2
-rw-r--r--arch/s390/mm/extable.c18
-rw-r--r--arch/s390/mm/fault.c461
-rw-r--r--arch/s390/mm/gmap.c5
-rw-r--r--arch/s390/mm/init.c8
-rw-r--r--arch/s390/mm/maccess.c2
-rw-r--r--arch/s390/mm/page-states.c206
-rw-r--r--arch/s390/mm/pageattr.c2
-rw-r--r--arch/s390/mm/pgalloc.c304
-rw-r--r--arch/s390/mm/vmem.c11
11 files changed, 248 insertions, 772 deletions
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index f475153132..f8b13f2476 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -332,7 +332,6 @@ static struct ctl_table cmm_table[] = {
.mode = 0644,
.proc_handler = cmm_timeout_handler,
},
- { }
};
#ifdef CONFIG_CMM_IUCV
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index b51666967a..d37a8f607b 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -287,7 +287,7 @@ static int pt_dump_init(void)
* kernel ASCE. We need this to keep the page table walker functions
* from accessing non-existent entries.
*/
- max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2;
+ max_addr = (S390_lowcore.kernel_asce.val & _REGION_ENTRY_TYPE_MASK) >> 2;
max_addr = 1UL << (max_addr * 11 + 31);
address_markers[IDENTITY_AFTER_END_NR].start_address = ident_map_size;
address_markers[AMODE31_START_NR].start_address = (unsigned long)__samode31;
diff --git a/arch/s390/mm/extable.c b/arch/s390/mm/extable.c
index fe87291df9..0a0738a473 100644
--- a/arch/s390/mm/extable.c
+++ b/arch/s390/mm/extable.c
@@ -61,6 +61,22 @@ static bool ex_handler_ua_load_reg(const struct exception_table_entry *ex,
return true;
}
+static bool ex_handler_zeropad(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+ unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
+ unsigned int reg_data = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+ unsigned long data, addr, offset;
+
+ addr = regs->gprs[reg_addr];
+ offset = addr & (sizeof(unsigned long) - 1);
+ addr &= ~(sizeof(unsigned long) - 1);
+ data = *(unsigned long *)addr;
+ data <<= BITS_PER_BYTE * offset;
+ regs->gprs[reg_data] = data;
+ regs->psw.addr = extable_fixup(ex);
+ return true;
+}
+
bool fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *ex;
@@ -81,6 +97,8 @@ bool fixup_exception(struct pt_regs *regs)
return ex_handler_ua_load_reg(ex, false, regs);
case EX_TYPE_UA_LOAD_REGPAIR:
return ex_handler_ua_load_reg(ex, true, regs);
+ case EX_TYPE_ZEROPAD:
+ return ex_handler_zeropad(ex, regs);
}
panic("invalid exception table entry");
}
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b678295931..ab4098886e 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -3,17 +3,19 @@
* S390 version
* Copyright IBM Corp. 1999
* Author(s): Hartmut Penner (hp@de.ibm.com)
- * Ulrich Weigand (uweigand@de.ibm.com)
+ * Ulrich Weigand (uweigand@de.ibm.com)
*
* Derived from "arch/i386/mm/fault.c"
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/kernel_stat.h>
+#include <linux/mmu_context.h>
#include <linux/perf_event.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
+#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
@@ -34,38 +36,27 @@
#include <linux/kfence.h>
#include <asm/asm-extable.h>
#include <asm/asm-offsets.h>
+#include <asm/ptrace.h>
+#include <asm/fault.h>
#include <asm/diag.h>
#include <asm/gmap.h>
#include <asm/irq.h>
-#include <asm/mmu_context.h>
#include <asm/facility.h>
#include <asm/uv.h>
#include "../kernel/entry.h"
-#define __FAIL_ADDR_MASK -4096L
-
-/*
- * Allocate private vm_fault_reason from top. Please make sure it won't
- * collide with vm_fault_reason.
- */
-#define VM_FAULT_BADCONTEXT ((__force vm_fault_t)0x80000000)
-#define VM_FAULT_BADMAP ((__force vm_fault_t)0x40000000)
-#define VM_FAULT_BADACCESS ((__force vm_fault_t)0x20000000)
-#define VM_FAULT_SIGNAL ((__force vm_fault_t)0x10000000)
-#define VM_FAULT_PFAULT ((__force vm_fault_t)0x8000000)
-
enum fault_type {
KERNEL_FAULT,
USER_FAULT,
GMAP_FAULT,
};
-static unsigned long store_indication __read_mostly;
+static DEFINE_STATIC_KEY_FALSE(have_store_indication);
static int __init fault_init(void)
{
if (test_facility(75))
- store_indication = 0xc00;
+ static_branch_enable(&have_store_indication);
return 0;
}
early_initcall(fault_init);
@@ -75,11 +66,9 @@ early_initcall(fault_init);
*/
static enum fault_type get_fault_type(struct pt_regs *regs)
{
- unsigned long trans_exc_code;
+ union teid teid = { .val = regs->int_parm_long };
- trans_exc_code = regs->int_parm_long & 3;
- if (likely(trans_exc_code == 0)) {
- /* primary space exception */
+ if (likely(teid.as == PSW_BITS_AS_PRIMARY)) {
if (user_mode(regs))
return USER_FAULT;
if (!IS_ENABLED(CONFIG_PGSTE))
@@ -88,83 +77,77 @@ static enum fault_type get_fault_type(struct pt_regs *regs)
return GMAP_FAULT;
return KERNEL_FAULT;
}
- if (trans_exc_code == 2)
+ if (teid.as == PSW_BITS_AS_SECONDARY)
return USER_FAULT;
- if (trans_exc_code == 1) {
- /* access register mode, not used in the kernel */
+ /* Access register mode, not used in the kernel */
+ if (teid.as == PSW_BITS_AS_ACCREG)
return USER_FAULT;
- }
- /* home space exception -> access via kernel ASCE */
+ /* Home space -> access via kernel ASCE */
return KERNEL_FAULT;
}
static unsigned long get_fault_address(struct pt_regs *regs)
{
- unsigned long trans_exc_code = regs->int_parm_long;
-
- return trans_exc_code & __FAIL_ADDR_MASK;
-}
-
-static bool fault_is_write(struct pt_regs *regs)
-{
- unsigned long trans_exc_code = regs->int_parm_long;
+ union teid teid = { .val = regs->int_parm_long };
- return (trans_exc_code & store_indication) == 0x400;
+ return teid.addr * PAGE_SIZE;
}
-static int bad_address(void *p)
+static __always_inline bool fault_is_write(struct pt_regs *regs)
{
- unsigned long dummy;
+ union teid teid = { .val = regs->int_parm_long };
- return get_kernel_nofault(dummy, (unsigned long *)p);
+ if (static_branch_likely(&have_store_indication))
+ return teid.fsi == TEID_FSI_STORE;
+ return false;
}
static void dump_pagetable(unsigned long asce, unsigned long address)
{
- unsigned long *table = __va(asce & _ASCE_ORIGIN);
+ unsigned long entry, *table = __va(asce & _ASCE_ORIGIN);
pr_alert("AS:%016lx ", asce);
switch (asce & _ASCE_TYPE_MASK) {
case _ASCE_TYPE_REGION1:
table += (address & _REGION1_INDEX) >> _REGION1_SHIFT;
- if (bad_address(table))
+ if (get_kernel_nofault(entry, table))
goto bad;
- pr_cont("R1:%016lx ", *table);
- if (*table & _REGION_ENTRY_INVALID)
+ pr_cont("R1:%016lx ", entry);
+ if (entry & _REGION_ENTRY_INVALID)
goto out;
- table = __va(*table & _REGION_ENTRY_ORIGIN);
+ table = __va(entry & _REGION_ENTRY_ORIGIN);
fallthrough;
case _ASCE_TYPE_REGION2:
table += (address & _REGION2_INDEX) >> _REGION2_SHIFT;
- if (bad_address(table))
+ if (get_kernel_nofault(entry, table))
goto bad;
- pr_cont("R2:%016lx ", *table);
- if (*table & _REGION_ENTRY_INVALID)
+ pr_cont("R2:%016lx ", entry);
+ if (entry & _REGION_ENTRY_INVALID)
goto out;
- table = __va(*table & _REGION_ENTRY_ORIGIN);
+ table = __va(entry & _REGION_ENTRY_ORIGIN);
fallthrough;
case _ASCE_TYPE_REGION3:
table += (address & _REGION3_INDEX) >> _REGION3_SHIFT;
- if (bad_address(table))
+ if (get_kernel_nofault(entry, table))
goto bad;
- pr_cont("R3:%016lx ", *table);
- if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE))
+ pr_cont("R3:%016lx ", entry);
+ if (entry & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE))
goto out;
- table = __va(*table & _REGION_ENTRY_ORIGIN);
+ table = __va(entry & _REGION_ENTRY_ORIGIN);
fallthrough;
case _ASCE_TYPE_SEGMENT:
table += (address & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
- if (bad_address(table))
+ if (get_kernel_nofault(entry, table))
goto bad;
- pr_cont("S:%016lx ", *table);
- if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE))
+ pr_cont("S:%016lx ", entry);
+ if (entry & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE))
goto out;
- table = __va(*table & _SEGMENT_ENTRY_ORIGIN);
+ table = __va(entry & _SEGMENT_ENTRY_ORIGIN);
}
table += (address & _PAGE_INDEX) >> _PAGE_SHIFT;
- if (bad_address(table))
+ if (get_kernel_nofault(entry, table))
goto bad;
- pr_cont("P:%016lx ", *table);
+ pr_cont("P:%016lx ", entry);
out:
pr_cont("\n");
return;
@@ -174,173 +157,113 @@ bad:
static void dump_fault_info(struct pt_regs *regs)
{
+ union teid teid = { .val = regs->int_parm_long };
unsigned long asce;
pr_alert("Failing address: %016lx TEID: %016lx\n",
- regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
+ get_fault_address(regs), teid.val);
pr_alert("Fault in ");
- switch (regs->int_parm_long & 3) {
- case 3:
+ switch (teid.as) {
+ case PSW_BITS_AS_HOME:
pr_cont("home space ");
break;
- case 2:
+ case PSW_BITS_AS_SECONDARY:
pr_cont("secondary space ");
break;
- case 1:
+ case PSW_BITS_AS_ACCREG:
pr_cont("access register ");
break;
- case 0:
+ case PSW_BITS_AS_PRIMARY:
pr_cont("primary space ");
break;
}
pr_cont("mode while using ");
switch (get_fault_type(regs)) {
case USER_FAULT:
- asce = S390_lowcore.user_asce;
+ asce = S390_lowcore.user_asce.val;
pr_cont("user ");
break;
case GMAP_FAULT:
- asce = ((struct gmap *) S390_lowcore.gmap)->asce;
+ asce = ((struct gmap *)S390_lowcore.gmap)->asce;
pr_cont("gmap ");
break;
case KERNEL_FAULT:
- asce = S390_lowcore.kernel_asce;
+ asce = S390_lowcore.kernel_asce.val;
pr_cont("kernel ");
break;
default:
unreachable();
}
pr_cont("ASCE.\n");
- dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK);
+ dump_pagetable(asce, get_fault_address(regs));
}
int show_unhandled_signals = 1;
void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault)
{
+ static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
+
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
if (!unhandled_signal(current, signr))
return;
- if (!printk_ratelimit())
+ if (!__ratelimit(&rs))
return;
- printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ",
- regs->int_code & 0xffff, regs->int_code >> 17);
+ pr_alert("User process fault: interruption code %04x ilc:%d ",
+ regs->int_code & 0xffff, regs->int_code >> 17);
print_vma_addr(KERN_CONT "in ", regs->psw.addr);
- printk(KERN_CONT "\n");
+ pr_cont("\n");
if (is_mm_fault)
dump_fault_info(regs);
show_regs(regs);
}
-/*
- * Send SIGSEGV to task. This is an external routine
- * to keep the stack usage of do_page_fault small.
- */
-static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
+static void do_sigsegv(struct pt_regs *regs, int si_code)
{
report_user_fault(regs, SIGSEGV, 1);
- force_sig_fault(SIGSEGV, si_code,
- (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
+ force_sig_fault(SIGSEGV, si_code, (void __user *)get_fault_address(regs));
}
-static noinline void do_no_context(struct pt_regs *regs, vm_fault_t fault)
+static void handle_fault_error_nolock(struct pt_regs *regs, int si_code)
{
enum fault_type fault_type;
unsigned long address;
bool is_write;
+ if (user_mode(regs)) {
+ if (WARN_ON_ONCE(!si_code))
+ si_code = SEGV_MAPERR;
+ return do_sigsegv(regs, si_code);
+ }
if (fixup_exception(regs))
return;
fault_type = get_fault_type(regs);
- if ((fault_type == KERNEL_FAULT) && (fault == VM_FAULT_BADCONTEXT)) {
+ if (fault_type == KERNEL_FAULT) {
address = get_fault_address(regs);
is_write = fault_is_write(regs);
if (kfence_handle_page_fault(address, is_write, regs))
return;
}
- /*
- * Oops. The kernel tried to access some bad page. We'll have to
- * terminate things with extreme prejudice.
- */
if (fault_type == KERNEL_FAULT)
- printk(KERN_ALERT "Unable to handle kernel pointer dereference"
- " in virtual kernel address space\n");
+ pr_alert("Unable to handle kernel pointer dereference in virtual kernel address space\n");
else
- printk(KERN_ALERT "Unable to handle kernel paging request"
- " in virtual user address space\n");
+ pr_alert("Unable to handle kernel paging request in virtual user address space\n");
dump_fault_info(regs);
die(regs, "Oops");
}
-static noinline void do_low_address(struct pt_regs *regs)
+static void handle_fault_error(struct pt_regs *regs, int si_code)
{
- /* Low-address protection hit in kernel mode means
- NULL pointer write access in kernel mode. */
- if (regs->psw.mask & PSW_MASK_PSTATE) {
- /* Low-address protection hit in user mode 'cannot happen'. */
- die (regs, "Low-address protection");
- }
+ struct mm_struct *mm = current->mm;
- do_no_context(regs, VM_FAULT_BADACCESS);
+ mmap_read_unlock(mm);
+ handle_fault_error_nolock(regs, si_code);
}
-static noinline void do_sigbus(struct pt_regs *regs)
+static void do_sigbus(struct pt_regs *regs)
{
- /*
- * Send a sigbus, regardless of whether we were in kernel
- * or user mode.
- */
- force_sig_fault(SIGBUS, BUS_ADRERR,
- (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
-}
-
-static noinline void do_fault_error(struct pt_regs *regs, vm_fault_t fault)
-{
- int si_code;
-
- switch (fault) {
- case VM_FAULT_BADACCESS:
- case VM_FAULT_BADMAP:
- /* Bad memory access. Check if it is kernel or user space. */
- if (user_mode(regs)) {
- /* User mode accesses just cause a SIGSEGV */
- si_code = (fault == VM_FAULT_BADMAP) ?
- SEGV_MAPERR : SEGV_ACCERR;
- do_sigsegv(regs, si_code);
- break;
- }
- fallthrough;
- case VM_FAULT_BADCONTEXT:
- case VM_FAULT_PFAULT:
- do_no_context(regs, fault);
- break;
- case VM_FAULT_SIGNAL:
- if (!user_mode(regs))
- do_no_context(regs, fault);
- break;
- default: /* fault & VM_FAULT_ERROR */
- if (fault & VM_FAULT_OOM) {
- if (!user_mode(regs))
- do_no_context(regs, fault);
- else
- pagefault_out_of_memory();
- } else if (fault & VM_FAULT_SIGSEGV) {
- /* Kernel mode? Handle exceptions or die */
- if (!user_mode(regs))
- do_no_context(regs, fault);
- else
- do_sigsegv(regs, SEGV_MAPERR);
- } else if (fault & VM_FAULT_SIGBUS) {
- /* Kernel mode? Handle exceptions or die */
- if (!user_mode(regs))
- do_no_context(regs, fault);
- else
- do_sigbus(regs);
- } else
- BUG();
- break;
- }
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)get_fault_address(regs));
}
/*
@@ -349,20 +272,20 @@ static noinline void do_fault_error(struct pt_regs *regs, vm_fault_t fault)
* routines.
*
* interruption code (int_code):
- * 04 Protection -> Write-Protection (suppression)
- * 10 Segment translation -> Not present (nullification)
- * 11 Page translation -> Not present (nullification)
- * 3b Region third trans. -> Not present (nullification)
+ * 04 Protection -> Write-Protection (suppression)
+ * 10 Segment translation -> Not present (nullification)
+ * 11 Page translation -> Not present (nullification)
+ * 3b Region third trans. -> Not present (nullification)
*/
-static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
+static void do_exception(struct pt_regs *regs, int access)
{
- struct gmap *gmap;
+ struct vm_area_struct *vma;
struct task_struct *tsk;
+ unsigned long address;
struct mm_struct *mm;
- struct vm_area_struct *vma;
enum fault_type type;
- unsigned long address;
unsigned int flags;
+ struct gmap *gmap;
vm_fault_t fault;
bool is_write;
@@ -372,31 +295,21 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
* been nullified. Don't signal single step via SIGTRAP.
*/
clear_thread_flag(TIF_PER_TRAP);
-
if (kprobe_page_fault(regs, 14))
- return 0;
-
+ return;
mm = tsk->mm;
address = get_fault_address(regs);
is_write = fault_is_write(regs);
-
- /*
- * Verify that the fault happened in user space, that
- * we are not in an interrupt and that there is a
- * user context.
- */
- fault = VM_FAULT_BADCONTEXT;
type = get_fault_type(regs);
switch (type) {
case KERNEL_FAULT:
- goto out;
+ return handle_fault_error_nolock(regs, 0);
case USER_FAULT:
case GMAP_FAULT:
if (faulthandler_disabled() || !mm)
- goto out;
+ return handle_fault_error_nolock(regs, 0);
break;
}
-
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
flags = FAULT_FLAG_DEFAULT;
if (user_mode(regs))
@@ -419,125 +332,120 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
vma_end_read(vma);
if (!(fault & VM_FAULT_RETRY)) {
count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
- if (likely(!(fault & VM_FAULT_ERROR)))
- fault = 0;
- goto out;
+ if (unlikely(fault & VM_FAULT_ERROR))
+ goto error;
+ return;
}
count_vm_vma_lock_event(VMA_LOCK_RETRY);
+ if (fault & VM_FAULT_MAJOR)
+ flags |= FAULT_FLAG_TRIED;
+
/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
- fault = VM_FAULT_SIGNAL;
- goto out;
+ if (!user_mode(regs))
+ handle_fault_error_nolock(regs, 0);
+ return;
}
lock_mmap:
mmap_read_lock(mm);
-
gmap = NULL;
if (IS_ENABLED(CONFIG_PGSTE) && type == GMAP_FAULT) {
- gmap = (struct gmap *) S390_lowcore.gmap;
+ gmap = (struct gmap *)S390_lowcore.gmap;
current->thread.gmap_addr = address;
current->thread.gmap_write_flag = !!(flags & FAULT_FLAG_WRITE);
current->thread.gmap_int_code = regs->int_code & 0xffff;
address = __gmap_translate(gmap, address);
- if (address == -EFAULT) {
- fault = VM_FAULT_BADMAP;
- goto out_up;
- }
+ if (address == -EFAULT)
+ return handle_fault_error(regs, SEGV_MAPERR);
if (gmap->pfault_enabled)
flags |= FAULT_FLAG_RETRY_NOWAIT;
}
-
retry:
- fault = VM_FAULT_BADMAP;
vma = find_vma(mm, address);
if (!vma)
- goto out_up;
-
+ return handle_fault_error(regs, SEGV_MAPERR);
if (unlikely(vma->vm_start > address)) {
if (!(vma->vm_flags & VM_GROWSDOWN))
- goto out_up;
+ return handle_fault_error(regs, SEGV_MAPERR);
vma = expand_stack(mm, address);
if (!vma)
- goto out;
+ return handle_fault_error_nolock(regs, SEGV_MAPERR);
}
-
- /*
- * Ok, we have a good vm_area for this memory access, so
- * we can handle it..
- */
- fault = VM_FAULT_BADACCESS;
if (unlikely(!(vma->vm_flags & access)))
- goto out_up;
-
- /*
- * If for any reason at all we couldn't handle the fault,
- * make sure we exit gracefully rather than endlessly redo
- * the fault.
- */
+ return handle_fault_error(regs, SEGV_ACCERR);
fault = handle_mm_fault(vma, address, flags, regs);
if (fault_signal_pending(fault, regs)) {
- fault = VM_FAULT_SIGNAL;
if (flags & FAULT_FLAG_RETRY_NOWAIT)
- goto out_up;
- goto out;
+ mmap_read_unlock(mm);
+ if (!user_mode(regs))
+ handle_fault_error_nolock(regs, 0);
+ return;
}
-
/* The fault is fully completed (including releasing mmap lock) */
if (fault & VM_FAULT_COMPLETED) {
if (gmap) {
mmap_read_lock(mm);
- goto out_gmap;
+ goto gmap;
}
- fault = 0;
- goto out;
+ return;
+ }
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ mmap_read_unlock(mm);
+ goto error;
}
-
- if (unlikely(fault & VM_FAULT_ERROR))
- goto out_up;
-
if (fault & VM_FAULT_RETRY) {
- if (IS_ENABLED(CONFIG_PGSTE) && gmap &&
- (flags & FAULT_FLAG_RETRY_NOWAIT)) {
+ if (IS_ENABLED(CONFIG_PGSTE) && gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) {
/*
- * FAULT_FLAG_RETRY_NOWAIT has been set, mmap_lock has
- * not been released
+ * FAULT_FLAG_RETRY_NOWAIT has been set,
+ * mmap_lock has not been released
*/
current->thread.gmap_pfault = 1;
- fault = VM_FAULT_PFAULT;
- goto out_up;
+ return handle_fault_error(regs, 0);
}
flags &= ~FAULT_FLAG_RETRY_NOWAIT;
flags |= FAULT_FLAG_TRIED;
mmap_read_lock(mm);
goto retry;
}
-out_gmap:
+gmap:
if (IS_ENABLED(CONFIG_PGSTE) && gmap) {
address = __gmap_link(gmap, current->thread.gmap_addr,
address);
- if (address == -EFAULT) {
- fault = VM_FAULT_BADMAP;
- goto out_up;
- }
+ if (address == -EFAULT)
+ return handle_fault_error(regs, SEGV_MAPERR);
if (address == -ENOMEM) {
fault = VM_FAULT_OOM;
- goto out_up;
+ mmap_read_unlock(mm);
+ goto error;
}
}
- fault = 0;
-out_up:
mmap_read_unlock(mm);
-out:
- return fault;
+ return;
+error:
+ if (fault & VM_FAULT_OOM) {
+ if (!user_mode(regs))
+ handle_fault_error_nolock(regs, 0);
+ else
+ pagefault_out_of_memory();
+ } else if (fault & VM_FAULT_SIGSEGV) {
+ if (!user_mode(regs))
+ handle_fault_error_nolock(regs, 0);
+ else
+ do_sigsegv(regs, SEGV_MAPERR);
+ } else if (fault & VM_FAULT_SIGBUS) {
+ if (!user_mode(regs))
+ handle_fault_error_nolock(regs, 0);
+ else
+ do_sigbus(regs);
+ } else {
+ BUG();
+ }
}
void do_protection_exception(struct pt_regs *regs)
{
- unsigned long trans_exc_code;
- int access;
- vm_fault_t fault;
+ union teid teid = { .val = regs->int_parm_long };
- trans_exc_code = regs->int_parm_long;
/*
* Protection exceptions are suppressing, decrement psw address.
* The exception to this rule are aborted transactions, for these
@@ -550,33 +458,28 @@ void do_protection_exception(struct pt_regs *regs)
* as a special case because the translation exception code
* field is not guaranteed to contain valid data in this case.
*/
- if (unlikely(!(trans_exc_code & 4))) {
- do_low_address(regs);
- return;
+ if (unlikely(!teid.b61)) {
+ if (user_mode(regs)) {
+ /* Low-address protection in user mode: cannot happen */
+ die(regs, "Low-address protection");
+ }
+ /*
+ * Low-address protection in kernel mode means
+ * NULL pointer write access in kernel mode.
+ */
+ return handle_fault_error_nolock(regs, 0);
}
- if (unlikely(MACHINE_HAS_NX && (trans_exc_code & 0x80))) {
- regs->int_parm_long = (trans_exc_code & ~PAGE_MASK) |
- (regs->psw.addr & PAGE_MASK);
- access = VM_EXEC;
- fault = VM_FAULT_BADACCESS;
- } else {
- access = VM_WRITE;
- fault = do_exception(regs, access);
+ if (unlikely(MACHINE_HAS_NX && teid.b56)) {
+ regs->int_parm_long = (teid.addr * PAGE_SIZE) | (regs->psw.addr & PAGE_MASK);
+ return handle_fault_error_nolock(regs, SEGV_ACCERR);
}
- if (unlikely(fault))
- do_fault_error(regs, fault);
+ do_exception(regs, VM_WRITE);
}
NOKPROBE_SYMBOL(do_protection_exception);
void do_dat_exception(struct pt_regs *regs)
{
- int access;
- vm_fault_t fault;
-
- access = VM_ACCESS_FLAGS;
- fault = do_exception(regs, access);
- if (unlikely(fault))
- do_fault_error(regs, fault);
+ do_exception(regs, VM_ACCESS_FLAGS);
}
NOKPROBE_SYMBOL(do_dat_exception);
@@ -584,7 +487,8 @@ NOKPROBE_SYMBOL(do_dat_exception);
void do_secure_storage_access(struct pt_regs *regs)
{
- unsigned long addr = regs->int_parm_long & __FAIL_ADDR_MASK;
+ union teid teid = { .val = regs->int_parm_long };
+ unsigned long addr = get_fault_address(regs);
struct vm_area_struct *vma;
struct mm_struct *mm;
struct page *page;
@@ -592,14 +496,12 @@ void do_secure_storage_access(struct pt_regs *regs)
int rc;
/*
- * bit 61 tells us if the address is valid, if it's not we
- * have a major problem and should stop the kernel or send a
- * SIGSEGV to the process. Unfortunately bit 61 is not
- * reliable without the misc UV feature so we need to check
- * for that as well.
+ * Bit 61 indicates if the address is valid, if it is not the
+ * kernel should be stopped or SIGSEGV should be sent to the
+ * process. Bit 61 is not reliable without the misc UV feature,
+ * therefore this needs to be checked too.
*/
- if (uv_has_feature(BIT_UV_FEAT_MISC) &&
- !test_bit_inv(61, &regs->int_parm_long)) {
+ if (uv_has_feature(BIT_UV_FEAT_MISC) && !teid.b61) {
/*
* When this happens, userspace did something that it
* was not supposed to do, e.g. branching into secure
@@ -609,14 +511,12 @@ void do_secure_storage_access(struct pt_regs *regs)
send_sig(SIGSEGV, current, 0);
return;
}
-
/*
- * The kernel should never run into this case and we
- * have no way out of this situation.
+ * The kernel should never run into this case and
+ * there is no way out of this situation.
*/
panic("Unexpected PGM 0x3d with TEID bit 61=0");
}
-
switch (get_fault_type(regs)) {
case GMAP_FAULT:
mm = current->mm;
@@ -624,20 +524,15 @@ void do_secure_storage_access(struct pt_regs *regs)
mmap_read_lock(mm);
addr = __gmap_translate(gmap, addr);
mmap_read_unlock(mm);
- if (IS_ERR_VALUE(addr)) {
- do_fault_error(regs, VM_FAULT_BADMAP);
- break;
- }
+ if (IS_ERR_VALUE(addr))
+ return handle_fault_error_nolock(regs, SEGV_MAPERR);
fallthrough;
case USER_FAULT:
mm = current->mm;
mmap_read_lock(mm);
vma = find_vma(mm, addr);
- if (!vma) {
- mmap_read_unlock(mm);
- do_fault_error(regs, VM_FAULT_BADMAP);
- break;
- }
+ if (!vma)
+ return handle_fault_error(regs, SEGV_MAPERR);
page = follow_page(vma, addr, FOLL_WRITE | FOLL_GET);
if (IS_ERR_OR_NULL(page)) {
mmap_read_unlock(mm);
@@ -658,23 +553,18 @@ void do_secure_storage_access(struct pt_regs *regs)
BUG();
break;
default:
- do_fault_error(regs, VM_FAULT_BADMAP);
- WARN_ON_ONCE(1);
+ unreachable();
}
}
NOKPROBE_SYMBOL(do_secure_storage_access);
void do_non_secure_storage_access(struct pt_regs *regs)
{
- unsigned long gaddr = regs->int_parm_long & __FAIL_ADDR_MASK;
struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
+ unsigned long gaddr = get_fault_address(regs);
- if (get_fault_type(regs) != GMAP_FAULT) {
- do_fault_error(regs, VM_FAULT_BADMAP);
- WARN_ON_ONCE(1);
- return;
- }
-
+ if (WARN_ON_ONCE(get_fault_type(regs) != GMAP_FAULT))
+ return handle_fault_error_nolock(regs, SEGV_MAPERR);
if (gmap_convert_to_secure(gmap, gaddr) == -EINVAL)
send_sig(SIGSEGV, current, 0);
}
@@ -682,8 +572,8 @@ NOKPROBE_SYMBOL(do_non_secure_storage_access);
void do_secure_storage_violation(struct pt_regs *regs)
{
- unsigned long gaddr = regs->int_parm_long & __FAIL_ADDR_MASK;
struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
+ unsigned long gaddr = get_fault_address(regs);
/*
* If the VM has been rebooted, its address space might still contain
@@ -699,9 +589,8 @@ void do_secure_storage_violation(struct pt_regs *regs)
* This exception is only triggered when a guest 2 is running
* and can therefore never occur in kernel context.
*/
- printk_ratelimited(KERN_WARNING
- "Secure storage violation in task: %s, pid %d\n",
- current->comm, current->pid);
+ pr_warn_ratelimited("Secure storage violation in task: %s, pid %d\n",
+ current->comm, current->pid);
send_sig(SIGSEGV, current, 0);
}
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 20786f6883..8da39deb56 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -18,7 +18,7 @@
#include <linux/ksm.h>
#include <linux/mman.h>
#include <linux/pgtable.h>
-
+#include <asm/page-states.h>
#include <asm/pgalloc.h>
#include <asm/gmap.h>
#include <asm/page.h>
@@ -33,7 +33,7 @@ static struct page *gmap_alloc_crst(void)
page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
if (!page)
return NULL;
- arch_set_page_dat(page, CRST_ALLOC_ORDER);
+ __arch_set_page_dat(page_to_virt(page), 1UL << CRST_ALLOC_ORDER);
return page;
}
@@ -1691,6 +1691,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
return ERR_PTR(-ENOMEM);
new->mm = parent->mm;
new->parent = gmap_get(parent);
+ new->private = parent->private;
new->orig_asce = asce;
new->edat_level = edat_level;
new->initialized = false;
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 8b94d2212d..43e612bc2b 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -35,6 +35,7 @@
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/pgalloc.h>
+#include <asm/ctlreg.h>
#include <asm/kfence.h>
#include <asm/ptdump.h>
#include <asm/dma.h>
@@ -42,7 +43,6 @@
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
-#include <asm/ctl_reg.h>
#include <asm/sclp.h>
#include <asm/set_memory.h>
#include <asm/kasan.h>
@@ -54,7 +54,7 @@
pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
-unsigned long __bootdata_preserved(s390_invalid_asce);
+struct ctlreg __bootdata_preserved(s390_invalid_asce);
unsigned long empty_zero_page, zero_page_mask;
EXPORT_SYMBOL(empty_zero_page);
@@ -164,14 +164,10 @@ void __init mem_init(void)
pv_init();
kfence_split_mapping();
- /* Setup guest page hinting */
- cmma_init();
/* this will put all low memory onto the freelists */
memblock_free_all();
setup_zero_pages(); /* Setup zeroed pages. */
-
- cmma_init_nodat();
}
void free_initmem(void)
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index c805b3e259..632c3a55fe 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -15,10 +15,10 @@
#include <linux/uio.h>
#include <linux/io.h>
#include <asm/asm-extable.h>
-#include <asm/ctl_reg.h>
#include <asm/abs_lowcore.h>
#include <asm/stacktrace.h>
#include <asm/maccess.h>
+#include <asm/ctlreg.h>
unsigned long __bootdata_preserved(__memcpy_real_area);
pte_t *__bootdata_preserved(memcpy_real_ptep);
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
index 79a037f49f..01f9b39e65 100644
--- a/arch/s390/mm/page-states.c
+++ b/arch/s390/mm/page-states.c
@@ -7,205 +7,18 @@
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/types.h>
#include <linux/mm.h>
-#include <linux/memblock.h>
-#include <linux/gfp.h>
-#include <linux/init.h>
-#include <asm/asm-extable.h>
-#include <asm/facility.h>
#include <asm/page-states.h>
+#include <asm/sections.h>
+#include <asm/page.h>
-static int cmma_flag = 1;
-
-static int __init cmma(char *str)
-{
- bool enabled;
-
- if (!kstrtobool(str, &enabled))
- cmma_flag = enabled;
- return 1;
-}
-__setup("cmma=", cmma);
-
-static inline int cmma_test_essa(void)
-{
- unsigned long tmp = 0;
- int rc = -EOPNOTSUPP;
-
- /* test ESSA_GET_STATE */
- asm volatile(
- " .insn rrf,0xb9ab0000,%[tmp],%[tmp],%[cmd],0\n"
- "0: la %[rc],0\n"
- "1:\n"
- EX_TABLE(0b,1b)
- : [rc] "+&d" (rc), [tmp] "+&d" (tmp)
- : [cmd] "i" (ESSA_GET_STATE));
- return rc;
-}
-
-void __init cmma_init(void)
-{
- if (!cmma_flag)
- return;
- if (cmma_test_essa()) {
- cmma_flag = 0;
- return;
- }
- if (test_facility(147))
- cmma_flag = 2;
-}
-
-static inline void set_page_unused(struct page *page, int order)
-{
- int i, rc;
-
- for (i = 0; i < (1 << order); i++)
- asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
- : "=&d" (rc)
- : "a" (page_to_phys(page + i)),
- "i" (ESSA_SET_UNUSED));
-}
-
-static inline void set_page_stable_dat(struct page *page, int order)
-{
- int i, rc;
-
- for (i = 0; i < (1 << order); i++)
- asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
- : "=&d" (rc)
- : "a" (page_to_phys(page + i)),
- "i" (ESSA_SET_STABLE));
-}
-
-static inline void set_page_stable_nodat(struct page *page, int order)
-{
- int i, rc;
-
- for (i = 0; i < (1 << order); i++)
- asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
- : "=&d" (rc)
- : "a" (page_to_phys(page + i)),
- "i" (ESSA_SET_STABLE_NODAT));
-}
-
-static void mark_kernel_pmd(pud_t *pud, unsigned long addr, unsigned long end)
-{
- unsigned long next;
- struct page *page;
- pmd_t *pmd;
-
- pmd = pmd_offset(pud, addr);
- do {
- next = pmd_addr_end(addr, end);
- if (pmd_none(*pmd) || pmd_large(*pmd))
- continue;
- page = phys_to_page(pmd_val(*pmd));
- set_bit(PG_arch_1, &page->flags);
- } while (pmd++, addr = next, addr != end);
-}
-
-static void mark_kernel_pud(p4d_t *p4d, unsigned long addr, unsigned long end)
-{
- unsigned long next;
- struct page *page;
- pud_t *pud;
- int i;
-
- pud = pud_offset(p4d, addr);
- do {
- next = pud_addr_end(addr, end);
- if (pud_none(*pud) || pud_large(*pud))
- continue;
- if (!pud_folded(*pud)) {
- page = phys_to_page(pud_val(*pud));
- for (i = 0; i < 4; i++)
- set_bit(PG_arch_1, &page[i].flags);
- }
- mark_kernel_pmd(pud, addr, next);
- } while (pud++, addr = next, addr != end);
-}
-
-static void mark_kernel_p4d(pgd_t *pgd, unsigned long addr, unsigned long end)
-{
- unsigned long next;
- struct page *page;
- p4d_t *p4d;
- int i;
-
- p4d = p4d_offset(pgd, addr);
- do {
- next = p4d_addr_end(addr, end);
- if (p4d_none(*p4d))
- continue;
- if (!p4d_folded(*p4d)) {
- page = phys_to_page(p4d_val(*p4d));
- for (i = 0; i < 4; i++)
- set_bit(PG_arch_1, &page[i].flags);
- }
- mark_kernel_pud(p4d, addr, next);
- } while (p4d++, addr = next, addr != end);
-}
-
-static void mark_kernel_pgd(void)
-{
- unsigned long addr, next;
- struct page *page;
- pgd_t *pgd;
- int i;
-
- addr = 0;
- pgd = pgd_offset_k(addr);
- do {
- next = pgd_addr_end(addr, MODULES_END);
- if (pgd_none(*pgd))
- continue;
- if (!pgd_folded(*pgd)) {
- page = phys_to_page(pgd_val(*pgd));
- for (i = 0; i < 4; i++)
- set_bit(PG_arch_1, &page[i].flags);
- }
- mark_kernel_p4d(pgd, addr, next);
- } while (pgd++, addr = next, addr != MODULES_END);
-}
-
-void __init cmma_init_nodat(void)
-{
- struct page *page;
- unsigned long start, end, ix;
- int i;
-
- if (cmma_flag < 2)
- return;
- /* Mark pages used in kernel page tables */
- mark_kernel_pgd();
- page = virt_to_page(&swapper_pg_dir);
- for (i = 0; i < 4; i++)
- set_bit(PG_arch_1, &page[i].flags);
- page = virt_to_page(&invalid_pg_dir);
- for (i = 0; i < 4; i++)
- set_bit(PG_arch_1, &page[i].flags);
-
- /* Set all kernel pages not used for page tables to stable/no-dat */
- for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
- page = pfn_to_page(start);
- for (ix = start; ix < end; ix++, page++) {
- if (__test_and_clear_bit(PG_arch_1, &page->flags))
- continue; /* skip page table pages */
- if (!list_empty(&page->lru))
- continue; /* skip free pages */
- set_page_stable_nodat(page, 0);
- }
- }
-}
+int __bootdata_preserved(cmma_flag);
void arch_free_page(struct page *page, int order)
{
if (!cmma_flag)
return;
- set_page_unused(page, order);
+ __set_page_unused(page_to_virt(page), 1UL << order);
}
void arch_alloc_page(struct page *page, int order)
@@ -213,14 +26,7 @@ void arch_alloc_page(struct page *page, int order)
if (!cmma_flag)
return;
if (cmma_flag < 2)
- set_page_stable_dat(page, order);
+ __set_page_stable_dat(page_to_virt(page), 1UL << order);
else
- set_page_stable_nodat(page, order);
-}
-
-void arch_set_page_dat(struct page *page, int order)
-{
- if (!cmma_flag)
- return;
- set_page_stable_dat(page, order);
+ __set_page_stable_nodat(page_to_virt(page), 1UL << order);
}
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index b87e96c64b..631e3a4ee2 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -75,7 +75,7 @@ static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
break;
}
table = (unsigned long *)((unsigned long)old & mask);
- crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
+ crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce.val);
} else if (MACHINE_HAS_IDTE) {
cspg(old, *old, new);
} else {
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 6396d6b06a..008e487c94 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -10,6 +10,7 @@
#include <linux/slab.h>
#include <linux/mm.h>
#include <asm/mmu_context.h>
+#include <asm/page-states.h>
#include <asm/pgalloc.h>
#include <asm/gmap.h>
#include <asm/tlb.h>
@@ -30,7 +31,6 @@ static struct ctl_table page_table_sysctl[] = {
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
- { }
};
static int __init page_table_register_sysctl(void)
@@ -44,11 +44,13 @@ __initcall(page_table_register_sysctl);
unsigned long *crst_table_alloc(struct mm_struct *mm)
{
struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
+ unsigned long *table;
if (!ptdesc)
return NULL;
- arch_set_page_dat(ptdesc_page(ptdesc), CRST_ALLOC_ORDER);
- return (unsigned long *) ptdesc_to_virt(ptdesc);
+ table = ptdesc_to_virt(ptdesc);
+ __arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
+ return table;
}
void crst_table_free(struct mm_struct *mm, unsigned long *table)
@@ -62,8 +64,8 @@ static void __crst_table_upgrade(void *arg)
/* change all active ASCEs to avoid the creation of new TLBs */
if (current->active_mm == mm) {
- S390_lowcore.user_asce = mm->context.asce;
- __ctl_load(S390_lowcore.user_asce, 7, 7);
+ S390_lowcore.user_asce.val = mm->context.asce;
+ local_ctl_load(7, &S390_lowcore.user_asce);
}
__tlb_flush_local();
}
@@ -131,11 +133,6 @@ err_p4d:
return -ENOMEM;
}
-static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
-{
- return atomic_fetch_xor(bits, v) ^ bits;
-}
-
#ifdef CONFIG_PGSTE
struct page *page_table_alloc_pgste(struct mm_struct *mm)
@@ -146,7 +143,7 @@ struct page *page_table_alloc_pgste(struct mm_struct *mm)
ptdesc = pagetable_alloc(GFP_KERNEL, 0);
if (ptdesc) {
table = (u64 *)ptdesc_to_virt(ptdesc);
- arch_set_page_dat(virt_to_page(table), 0);
+ __arch_set_page_dat(table, 1);
memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
}
@@ -160,125 +157,11 @@ void page_table_free_pgste(struct page *page)
#endif /* CONFIG_PGSTE */
-/*
- * A 2KB-pgtable is either upper or lower half of a normal page.
- * The second half of the page may be unused or used as another
- * 2KB-pgtable.
- *
- * Whenever possible the parent page for a new 2KB-pgtable is picked
- * from the list of partially allocated pages mm_context_t::pgtable_list.
- * In case the list is empty a new parent page is allocated and added to
- * the list.
- *
- * When a parent page gets fully allocated it contains 2KB-pgtables in both
- * upper and lower halves and is removed from mm_context_t::pgtable_list.
- *
- * When 2KB-pgtable is freed from to fully allocated parent page that
- * page turns partially allocated and added to mm_context_t::pgtable_list.
- *
- * If 2KB-pgtable is freed from the partially allocated parent page that
- * page turns unused and gets removed from mm_context_t::pgtable_list.
- * Furthermore, the unused parent page is released.
- *
- * As follows from the above, no unallocated or fully allocated parent
- * pages are contained in mm_context_t::pgtable_list.
- *
- * The upper byte (bits 24-31) of the parent page _refcount is used
- * for tracking contained 2KB-pgtables and has the following format:
- *
- * PP AA
- * 01234567 upper byte (bits 24-31) of struct page::_refcount
- * || ||
- * || |+--- upper 2KB-pgtable is allocated
- * || +---- lower 2KB-pgtable is allocated
- * |+------- upper 2KB-pgtable is pending for removal
- * +-------- lower 2KB-pgtable is pending for removal
- *
- * (See commit 620b4e903179 ("s390: use _refcount for pgtables") on why
- * using _refcount is possible).
- *
- * When 2KB-pgtable is allocated the corresponding AA bit is set to 1.
- * The parent page is either:
- * - added to mm_context_t::pgtable_list in case the second half of the
- * parent page is still unallocated;
- * - removed from mm_context_t::pgtable_list in case both hales of the
- * parent page are allocated;
- * These operations are protected with mm_context_t::lock.
- *
- * When 2KB-pgtable is deallocated the corresponding AA bit is set to 0
- * and the corresponding PP bit is set to 1 in a single atomic operation.
- * Thus, PP and AA bits corresponding to the same 2KB-pgtable are mutually
- * exclusive and may never be both set to 1!
- * The parent page is either:
- * - added to mm_context_t::pgtable_list in case the second half of the
- * parent page is still allocated;
- * - removed from mm_context_t::pgtable_list in case the second half of
- * the parent page is unallocated;
- * These operations are protected with mm_context_t::lock.
- *
- * It is important to understand that mm_context_t::lock only protects
- * mm_context_t::pgtable_list and AA bits, but not the parent page itself
- * and PP bits.
- *
- * Releasing the parent page happens whenever the PP bit turns from 1 to 0,
- * while both AA bits and the second PP bit are already unset. Then the
- * parent page does not contain any 2KB-pgtable fragment anymore, and it has
- * also been removed from mm_context_t::pgtable_list. It is safe to release
- * the page therefore.
- *
- * PGSTE memory spaces use full 4KB-pgtables and do not need most of the
- * logic described above. Both AA bits are set to 1 to denote a 4KB-pgtable
- * while the PP bits are never used, nor such a page is added to or removed
- * from mm_context_t::pgtable_list.
- *
- * pte_free_defer() overrides those rules: it takes the page off pgtable_list,
- * and prevents both 2K fragments from being reused. pte_free_defer() has to
- * guarantee that its pgtable cannot be reused before the RCU grace period
- * has elapsed (which page_table_free_rcu() does not actually guarantee).
- * But for simplicity, because page->rcu_head overlays page->lru, and because
- * the RCU callback might not be called before the mm_context_t has been freed,
- * pte_free_defer() in this implementation prevents both fragments from being
- * reused, and delays making the call to RCU until both fragments are freed.
- */
unsigned long *page_table_alloc(struct mm_struct *mm)
{
- unsigned long *table;
struct ptdesc *ptdesc;
- unsigned int mask, bit;
-
- /* Try to get a fragment of a 4K page as a 2K page table */
- if (!mm_alloc_pgste(mm)) {
- table = NULL;
- spin_lock_bh(&mm->context.lock);
- if (!list_empty(&mm->context.pgtable_list)) {
- ptdesc = list_first_entry(&mm->context.pgtable_list,
- struct ptdesc, pt_list);
- mask = atomic_read(&ptdesc->_refcount) >> 24;
- /*
- * The pending removal bits must also be checked.
- * Failure to do so might lead to an impossible
- * value of (i.e 0x13 or 0x23) written to _refcount.
- * Such values violate the assumption that pending and
- * allocation bits are mutually exclusive, and the rest
- * of the code unrails as result. That could lead to
- * a whole bunch of races and corruptions.
- */
- mask = (mask | (mask >> 4)) & 0x03U;
- if (mask != 0x03U) {
- table = (unsigned long *) ptdesc_to_virt(ptdesc);
- bit = mask & 1; /* =1 -> second 2K */
- if (bit)
- table += PTRS_PER_PTE;
- atomic_xor_bits(&ptdesc->_refcount,
- 0x01U << (bit + 24));
- list_del_init(&ptdesc->pt_list);
- }
- }
- spin_unlock_bh(&mm->context.lock);
- if (table)
- return table;
- }
- /* Allocate a fresh page */
+ unsigned long *table;
+
ptdesc = pagetable_alloc(GFP_KERNEL, 0);
if (!ptdesc)
return NULL;
@@ -286,177 +169,57 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
pagetable_free(ptdesc);
return NULL;
}
- arch_set_page_dat(ptdesc_page(ptdesc), 0);
- /* Initialize page table */
- table = (unsigned long *) ptdesc_to_virt(ptdesc);
- if (mm_alloc_pgste(mm)) {
- /* Return 4K page table with PGSTEs */
- INIT_LIST_HEAD(&ptdesc->pt_list);
- atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
- memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
- memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
- } else {
- /* Return the first 2K fragment of the page */
- atomic_xor_bits(&ptdesc->_refcount, 0x01U << 24);
- memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
- spin_lock_bh(&mm->context.lock);
- list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
- spin_unlock_bh(&mm->context.lock);
- }
+ table = ptdesc_to_virt(ptdesc);
+ __arch_set_page_dat(table, 1);
+ /* pt_list is used by gmap only */
+ INIT_LIST_HEAD(&ptdesc->pt_list);
+ memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
+ memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
return table;
}
-static void page_table_release_check(struct page *page, void *table,
- unsigned int half, unsigned int mask)
+static void pagetable_pte_dtor_free(struct ptdesc *ptdesc)
{
- char msg[128];
-
- if (!IS_ENABLED(CONFIG_DEBUG_VM))
- return;
- if (!mask && list_empty(&page->lru))
- return;
- snprintf(msg, sizeof(msg),
- "Invalid pgtable %p release half 0x%02x mask 0x%02x",
- table, half, mask);
- dump_page(page, msg);
-}
-
-static void pte_free_now(struct rcu_head *head)
-{
- struct ptdesc *ptdesc;
-
- ptdesc = container_of(head, struct ptdesc, pt_rcu_head);
pagetable_pte_dtor(ptdesc);
pagetable_free(ptdesc);
}
void page_table_free(struct mm_struct *mm, unsigned long *table)
{
- unsigned int mask, bit, half;
struct ptdesc *ptdesc = virt_to_ptdesc(table);
- if (!mm_alloc_pgste(mm)) {
- /* Free 2K page table fragment of a 4K page */
- bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
- spin_lock_bh(&mm->context.lock);
- /*
- * Mark the page for delayed release. The actual release
- * will happen outside of the critical section from this
- * function or from __tlb_remove_table()
- */
- mask = atomic_xor_bits(&ptdesc->_refcount, 0x11U << (bit + 24));
- mask >>= 24;
- if ((mask & 0x03U) && !folio_test_active(ptdesc_folio(ptdesc))) {
- /*
- * Other half is allocated, and neither half has had
- * its free deferred: add page to head of list, to make
- * this freed half available for immediate reuse.
- */
- list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
- } else {
- /* If page is on list, now remove it. */
- list_del_init(&ptdesc->pt_list);
- }
- spin_unlock_bh(&mm->context.lock);
- mask = atomic_xor_bits(&ptdesc->_refcount, 0x10U << (bit + 24));
- mask >>= 24;
- if (mask != 0x00U)
- return;
- half = 0x01U << bit;
- } else {
- half = 0x03U;
- mask = atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
- mask >>= 24;
- }
-
- page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
- if (folio_test_clear_active(ptdesc_folio(ptdesc)))
- call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
- else
- pte_free_now(&ptdesc->pt_rcu_head);
+ pagetable_pte_dtor_free(ptdesc);
}
-void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
- unsigned long vmaddr)
+void __tlb_remove_table(void *table)
{
- struct mm_struct *mm;
- unsigned int bit, mask;
struct ptdesc *ptdesc = virt_to_ptdesc(table);
+ struct page *page = ptdesc_page(ptdesc);
- mm = tlb->mm;
- if (mm_alloc_pgste(mm)) {
- gmap_unlink(mm, table, vmaddr);
- table = (unsigned long *) ((unsigned long)table | 0x03U);
- tlb_remove_ptdesc(tlb, table);
+ if (compound_order(page) == CRST_ALLOC_ORDER) {
+ /* pmd, pud, or p4d */
+ pagetable_free(ptdesc);
return;
}
- bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
- spin_lock_bh(&mm->context.lock);
- /*
- * Mark the page for delayed release. The actual release will happen
- * outside of the critical section from __tlb_remove_table() or from
- * page_table_free()
- */
- mask = atomic_xor_bits(&ptdesc->_refcount, 0x11U << (bit + 24));
- mask >>= 24;
- if ((mask & 0x03U) && !folio_test_active(ptdesc_folio(ptdesc))) {
- /*
- * Other half is allocated, and neither half has had
- * its free deferred: add page to end of list, to make
- * this freed half available for reuse once its pending
- * bit has been cleared by __tlb_remove_table().
- */
- list_add_tail(&ptdesc->pt_list, &mm->context.pgtable_list);
- } else {
- /* If page is on list, now remove it. */
- list_del_init(&ptdesc->pt_list);
- }
- spin_unlock_bh(&mm->context.lock);
- table = (unsigned long *) ((unsigned long) table | (0x01U << bit));
- tlb_remove_table(tlb, table);
+ pagetable_pte_dtor_free(ptdesc);
}
-void __tlb_remove_table(void *_table)
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void pte_free_now(struct rcu_head *head)
{
- unsigned int mask = (unsigned long) _table & 0x03U, half = mask;
- void *table = (void *)((unsigned long) _table ^ mask);
- struct ptdesc *ptdesc = virt_to_ptdesc(table);
-
- switch (half) {
- case 0x00U: /* pmd, pud, or p4d */
- pagetable_free(ptdesc);
- return;
- case 0x01U: /* lower 2K of a 4K page table */
- case 0x02U: /* higher 2K of a 4K page table */
- mask = atomic_xor_bits(&ptdesc->_refcount, mask << (4 + 24));
- mask >>= 24;
- if (mask != 0x00U)
- return;
- break;
- case 0x03U: /* 4K page table with pgstes */
- mask = atomic_xor_bits(&ptdesc->_refcount, 0x03U << 24);
- mask >>= 24;
- break;
- }
+ struct ptdesc *ptdesc = container_of(head, struct ptdesc, pt_rcu_head);
- page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
- if (folio_test_clear_active(ptdesc_folio(ptdesc)))
- call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
- else
- pte_free_now(&ptdesc->pt_rcu_head);
+ pagetable_pte_dtor_free(ptdesc);
}
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pte_free_defer(struct mm_struct *mm, pgtable_t pgtable)
{
- struct page *page;
+ struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
- page = virt_to_page(pgtable);
- SetPageActive(page);
- page_table_free(mm, (unsigned long *)pgtable);
+ call_rcu(&ptdesc->pt_rcu_head, pte_free_now);
/*
- * page_table_free() does not do the pgste gmap_unlink() which
- * page_table_free_rcu() does: warn us if pgste ever reaches here.
+ * THPs are not allowed for KVM guests. Warn if pgste ever reaches here.
+ * Turn to the generic pte_free_defer() version once gmap is removed.
*/
WARN_ON_ONCE(mm_has_pgste(mm));
}
@@ -489,11 +252,10 @@ static unsigned long *base_crst_alloc(unsigned long val)
unsigned long *table;
struct ptdesc *ptdesc;
- ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, CRST_ALLOC_ORDER);
+ ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
if (!ptdesc)
return NULL;
table = ptdesc_address(ptdesc);
-
crst_table_init(table, val);
return table;
}
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 6d276103c6..186a020857 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -15,6 +15,7 @@
#include <asm/page-states.h>
#include <asm/cacheflush.h>
#include <asm/nospec-branch.h>
+#include <asm/ctlreg.h>
#include <asm/pgalloc.h>
#include <asm/setup.h>
#include <asm/tlbflush.h>
@@ -49,8 +50,7 @@ void *vmem_crst_alloc(unsigned long val)
if (!table)
return NULL;
crst_table_init(table, val);
- if (slab_is_available())
- arch_set_page_dat(virt_to_page(table), CRST_ALLOC_ORDER);
+ __arch_set_page_dat(table, 1UL << CRST_ALLOC_ORDER);
return table;
}
@@ -66,6 +66,7 @@ pte_t __ref *vmem_pte_alloc(void)
if (!pte)
return NULL;
memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
+ __arch_set_page_dat(pte, 1);
return pte;
}
@@ -502,6 +503,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
return ret;
}
+#ifdef CONFIG_MEMORY_HOTPLUG
+
void vmemmap_free(unsigned long start, unsigned long end,
struct vmem_altmap *altmap)
{
@@ -510,6 +513,8 @@ void vmemmap_free(unsigned long start, unsigned long end,
mutex_unlock(&vmem_mutex);
}
+#endif
+
void vmem_remove_mapping(unsigned long start, unsigned long size)
{
mutex_lock(&vmem_mutex);
@@ -663,7 +668,7 @@ void __init vmem_map_init(void)
__set_memory_4k(__va(0), RELOC_HIDE(__va(0), ident_map_size));
}
if (MACHINE_HAS_NX)
- ctl_set_bit(0, 20);
+ system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
pr_info("Write protected kernel read-only data: %luk\n",
(unsigned long)(__end_rodata - _stext) >> 10);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 18:39:41 +0000