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-rw-r--r--arch/loongarch/Kconfig1
-rw-r--r--arch/loongarch/include/asm/kfence.h61
-rw-r--r--arch/loongarch/include/asm/pgtable.h11
-rw-r--r--arch/loongarch/mm/fault.c22
4 files changed, 86 insertions, 9 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 6cda4843f93b..0619ec165424 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -92,6 +92,7 @@ config LOONGARCH
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
+ select HAVE_ARCH_KFENCE
select HAVE_ARCH_KGDB if PERF_EVENTS
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_SECCOMP_FILTER
diff --git a/arch/loongarch/include/asm/kfence.h b/arch/loongarch/include/asm/kfence.h
new file mode 100644
index 000000000000..6c82aea1c993
--- /dev/null
+++ b/arch/loongarch/include/asm/kfence.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KFENCE support for LoongArch.
+ *
+ * Author: Enze Li <lienze@kylinos.cn>
+ * Copyright (C) 2022-2023 KylinSoft Corporation.
+ */
+
+#ifndef _ASM_LOONGARCH_KFENCE_H
+#define _ASM_LOONGARCH_KFENCE_H
+
+#include <linux/kfence.h>
+#include <asm/pgtable.h>
+#include <asm/tlb.h>
+
+static inline bool arch_kfence_init_pool(void)
+{
+ int err;
+ char *kfence_pool = __kfence_pool;
+ struct vm_struct *area;
+
+ area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP,
+ KFENCE_AREA_START, KFENCE_AREA_END,
+ __builtin_return_address(0));
+ if (!area)
+ return false;
+
+ __kfence_pool = (char *)area->addr;
+ err = ioremap_page_range((unsigned long)__kfence_pool,
+ (unsigned long)__kfence_pool + KFENCE_POOL_SIZE,
+ virt_to_phys((void *)kfence_pool), PAGE_KERNEL);
+ if (err) {
+ free_vm_area(area);
+ __kfence_pool = kfence_pool;
+ return false;
+ }
+
+ return true;
+}
+
+/* Protect the given page and flush TLB. */
+static inline bool kfence_protect_page(unsigned long addr, bool protect)
+{
+ pte_t *pte = virt_to_kpte(addr);
+
+ if (WARN_ON(!pte) || pte_none(*pte))
+ return false;
+
+ if (protect)
+ set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT)));
+ else
+ set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT)));
+
+ preempt_disable();
+ local_flush_tlb_one(addr);
+ preempt_enable();
+
+ return true;
+}
+
+#endif /* _ASM_LOONGARCH_KFENCE_H */
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index 338d1b147464..7e3708883994 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -82,14 +82,23 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
#define MODULES_VADDR (vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE))
#define MODULES_END (MODULES_VADDR + SZ_256M)
+#ifdef CONFIG_KFENCE
+#define KFENCE_AREA_SIZE (((CONFIG_KFENCE_NUM_OBJECTS + 1) * 2 + 2) * PAGE_SIZE)
+#else
+#define KFENCE_AREA_SIZE 0
+#endif
+
#define VMALLOC_START MODULES_END
#define VMALLOC_END \
(vm_map_base + \
- min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE - VMEMMAP_SIZE)
+ min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE - VMEMMAP_SIZE - KFENCE_AREA_SIZE)
#define vmemmap ((struct page *)((VMALLOC_END + PMD_SIZE) & PMD_MASK))
#define VMEMMAP_END ((unsigned long)vmemmap + VMEMMAP_SIZE - 1)
+#define KFENCE_AREA_START (VMEMMAP_END + 1)
+#define KFENCE_AREA_END (KFENCE_AREA_START + KFENCE_AREA_SIZE - 1)
+
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
#ifndef __PAGETABLE_PMD_FOLDED
diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c
index da5b6d518cdb..e6376e3dce86 100644
--- a/arch/loongarch/mm/fault.c
+++ b/arch/loongarch/mm/fault.c
@@ -23,6 +23,7 @@
#include <linux/kprobes.h>
#include <linux/perf_event.h>
#include <linux/uaccess.h>
+#include <linux/kfence.h>
#include <asm/branch.h>
#include <asm/mmu_context.h>
@@ -30,7 +31,8 @@
int show_unhandled_signals = 1;
-static void __kprobes no_context(struct pt_regs *regs, unsigned long address)
+static void __kprobes no_context(struct pt_regs *regs,
+ unsigned long write, unsigned long address)
{
const int field = sizeof(unsigned long) * 2;
@@ -38,6 +40,9 @@ static void __kprobes no_context(struct pt_regs *regs, unsigned long address)
if (fixup_exception(regs))
return;
+ if (kfence_handle_page_fault(address, write, regs))
+ return;
+
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
@@ -51,14 +56,15 @@ static void __kprobes no_context(struct pt_regs *regs, unsigned long address)
die("Oops", regs);
}
-static void __kprobes do_out_of_memory(struct pt_regs *regs, unsigned long address)
+static void __kprobes do_out_of_memory(struct pt_regs *regs,
+ unsigned long write, unsigned long address)
{
/*
* We ran out of memory, call the OOM killer, and return the userspace
* (which will retry the fault, or kill us if we got oom-killed).
*/
if (!user_mode(regs)) {
- no_context(regs, address);
+ no_context(regs, write, address);
return;
}
pagefault_out_of_memory();
@@ -69,7 +75,7 @@ static void __kprobes do_sigbus(struct pt_regs *regs,
{
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs)) {
- no_context(regs, address);
+ no_context(regs, write, address);
return;
}
@@ -90,7 +96,7 @@ static void __kprobes do_sigsegv(struct pt_regs *regs,
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs)) {
- no_context(regs, address);
+ no_context(regs, write, address);
return;
}
@@ -149,7 +155,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs,
*/
if (address & __UA_LIMIT) {
if (!user_mode(regs))
- no_context(regs, address);
+ no_context(regs, write, address);
else
do_sigsegv(regs, write, address, si_code);
return;
@@ -211,7 +217,7 @@ good_area:
if (fault_signal_pending(fault, regs)) {
if (!user_mode(regs))
- no_context(regs, address);
+ no_context(regs, write, address);
return;
}
@@ -232,7 +238,7 @@ good_area:
if (unlikely(fault & VM_FAULT_ERROR)) {
mmap_read_unlock(mm);
if (fault & VM_FAULT_OOM) {
- do_out_of_memory(regs, address);
+ do_out_of_memory(regs, write, address);
return;
} else if (fault & VM_FAULT_SIGSEGV) {
do_sigsegv(regs, write, address, si_code);
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-20 04:53:19 +0300