From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh
---
kernel/arch/arm64/mm/fault.c | 673 ++++++++++++++++++++++++++++++-------------------------
1 files changed, 367 insertions(+), 306 deletions(-)
diff --git a/kernel/arch/arm64/mm/fault.c b/kernel/arch/arm64/mm/fault.c
index d44543c..45e652d 100644
--- a/kernel/arch/arm64/mm/fault.c
+++ b/kernel/arch/arm64/mm/fault.c
@@ -1,28 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on arch/arm/mm/fault.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 1995-2004 Russell King
* Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
#include <linux/extable.h>
+#include <linux/kfence.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/hardirq.h>
#include <linux/init.h>
+#include <linux/kasan.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/page-flags.h>
@@ -33,23 +26,26 @@
#include <linux/preempt.h>
#include <linux/hugetlb.h>
+#include <asm/acpi.h>
#include <asm/bug.h>
#include <asm/cmpxchg.h>
#include <asm/cpufeature.h>
#include <asm/exception.h>
+#include <asm/daifflags.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
-#include <asm/kasan.h>
+#include <asm/kprobes.h>
+#include <asm/mte.h>
+#include <asm/processor.h>
#include <asm/sysreg.h>
#include <asm/system_misc.h>
-#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/traps.h>
-#include <acpi/ghes.h>
+#include <trace/hooks/fault.h>
struct fault_info {
- int (*fn)(unsigned long addr, unsigned int esr,
+ int (*fn)(unsigned long far, unsigned int esr,
struct pt_regs *regs);
int sig;
int code;
@@ -57,33 +53,17 @@
};
static const struct fault_info fault_info[];
+static struct fault_info debug_fault_info[];
static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
{
- return fault_info + (esr & 63);
+ return fault_info + (esr & ESR_ELx_FSC);
}
-#ifdef CONFIG_KPROBES
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
+static inline const struct fault_info *esr_to_debug_fault_info(unsigned int esr)
{
- int ret = 0;
-
- /* kprobe_running() needs smp_processor_id() */
- if (!user_mode(regs)) {
- preempt_disable();
- if (kprobe_running() && kprobe_fault_handler(regs, esr))
- ret = 1;
- preempt_enable();
- }
-
- return ret;
+ return debug_fault_info + DBG_ESR_EVT(esr);
}
-#else
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
-{
- return 0;
-}
-#endif
static void data_abort_decode(unsigned int esr)
{
@@ -112,8 +92,8 @@
pr_alert("Mem abort info:\n");
pr_alert(" ESR = 0x%08x\n", esr);
- pr_alert(" Exception class = %s, IL = %u bits\n",
- esr_get_class_string(esr),
+ pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
+ ESR_ELx_EC(esr), esr_get_class_string(esr),
(esr & ESR_ELx_IL) ? 32 : 16);
pr_alert(" SET = %lu, FnV = %lu\n",
(esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
@@ -126,22 +106,19 @@
data_abort_decode(esr);
}
-static inline bool is_ttbr0_addr(unsigned long addr)
+static inline unsigned long mm_to_pgd_phys(struct mm_struct *mm)
{
- /* entry assembly clears tags for TTBR0 addrs */
- return addr < TASK_SIZE;
-}
+ /* Either init_pg_dir or swapper_pg_dir */
+ if (mm == &init_mm)
+ return __pa_symbol(mm->pgd);
-static inline bool is_ttbr1_addr(unsigned long addr)
-{
- /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
- return arch_kasan_reset_tag(addr) >= VA_START;
+ return (unsigned long)virt_to_phys(mm->pgd);
}
/*
* Dump out the page tables associated with 'addr' in the currently active mm.
*/
-void show_pte(unsigned long addr)
+static void show_pte(unsigned long addr)
{
struct mm_struct *mm;
pgd_t *pgdp;
@@ -164,14 +141,15 @@
return;
}
- pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgdp = %p\n",
+ pr_alert("%s pgtable: %luk pages, %llu-bit VAs, pgdp=%016lx\n",
mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
- VA_BITS, mm->pgd);
+ vabits_actual, mm_to_pgd_phys(mm));
pgdp = pgd_offset(mm, addr);
pgd = READ_ONCE(*pgdp);
pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));
do {
+ p4d_t *p4dp, p4d;
pud_t *pudp, pud;
pmd_t *pmdp, pmd;
pte_t *ptep, pte;
@@ -179,7 +157,13 @@
if (pgd_none(pgd) || pgd_bad(pgd))
break;
- pudp = pud_offset(pgdp, addr);
+ p4dp = p4d_offset(pgdp, addr);
+ p4d = READ_ONCE(*p4dp);
+ pr_cont(", p4d=%016llx", p4d_val(p4d));
+ if (p4d_none(p4d) || p4d_bad(p4d))
+ break;
+
+ pudp = pud_offset(p4dp, addr);
pud = READ_ONCE(*pudp);
pr_cont(", pud=%016llx", pud_val(pud));
if (pud_none(pud) || pud_bad(pud))
@@ -239,7 +223,9 @@
pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
} while (pteval != old_pteval);
- flush_tlb_fix_spurious_fault(vma, address);
+ /* Invalidate a stale read-only entry */
+ if (dirty)
+ flush_tlb_page(vma, address);
return 1;
}
@@ -248,9 +234,8 @@
return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
}
-static inline bool is_el1_permission_fault(unsigned int esr,
- struct pt_regs *regs,
- unsigned long addr)
+static inline bool is_el1_permission_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
{
unsigned int ec = ESR_ELx_EC(esr);
unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
@@ -268,6 +253,38 @@
return false;
}
+static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ unsigned long flags;
+ u64 par, dfsc;
+
+ if (ESR_ELx_EC(esr) != ESR_ELx_EC_DABT_CUR ||
+ (esr & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT)
+ return false;
+
+ local_irq_save(flags);
+ asm volatile("at s1e1r, %0" :: "r" (addr));
+ isb();
+ par = read_sysreg_par();
+ local_irq_restore(flags);
+
+ /*
+ * If we now have a valid translation, treat the translation fault as
+ * spurious.
+ */
+ if (!(par & SYS_PAR_EL1_F))
+ return true;
+
+ /*
+ * If we got a different type of fault from the AT instruction,
+ * treat the translation fault as spurious.
+ */
+ dfsc = FIELD_GET(SYS_PAR_EL1_FST, par);
+ return (dfsc & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT;
+}
+
static void die_kernel_fault(const char *msg, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
@@ -276,12 +293,72 @@
pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg,
addr);
+ trace_android_rvh_die_kernel_fault(regs, esr, addr, msg);
mem_abort_decode(esr);
show_pte(addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
+}
+
+#ifdef CONFIG_KASAN_HW_TAGS
+static void report_tag_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ static bool reported;
+ bool is_write;
+
+ if (READ_ONCE(reported))
+ return;
+
+ /*
+ * This is used for KASAN tests and assumes that no MTE faults
+ * happened before running the tests.
+ */
+ if (mte_report_once())
+ WRITE_ONCE(reported, true);
+
+ /*
+ * SAS bits aren't set for all faults reported in EL1, so we can't
+ * find out access size.
+ */
+ is_write = !!(esr & ESR_ELx_WNR);
+ kasan_report(addr, 0, is_write, regs->pc);
+}
+#else
+/* Tag faults aren't enabled without CONFIG_KASAN_HW_TAGS. */
+static inline void report_tag_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs) { }
+#endif
+
+static void do_tag_recovery(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+
+ report_tag_fault(addr, esr, regs);
+
+ /*
+ * Disable MTE Tag Checking on the local CPU for the current EL.
+ * It will be done lazily on the other CPUs when they will hit a
+ * tag fault.
+ */
+ sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_NONE);
+ isb();
+}
+
+static bool is_el1_mte_sync_tag_check_fault(unsigned int esr)
+{
+ unsigned int ec = ESR_ELx_EC(esr);
+ unsigned int fsc = esr & ESR_ELx_FSC;
+
+ if (ec != ESR_ELx_EC_DABT_CUR)
+ return false;
+
+ if (fsc == ESR_ELx_FSC_MTE)
+ return true;
+
+ return false;
}
static void __do_kernel_fault(unsigned long addr, unsigned int esr,
@@ -296,23 +373,38 @@
if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
return;
- if (is_el1_permission_fault(esr, regs, addr)) {
+ if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs),
+ "Ignoring spurious kernel translation fault at virtual address %016lx\n", addr))
+ return;
+
+ if (is_el1_mte_sync_tag_check_fault(esr)) {
+ do_tag_recovery(addr, esr, regs);
+
+ return;
+ }
+
+ if (is_el1_permission_fault(addr, esr, regs)) {
if (esr & ESR_ELx_WNR)
msg = "write to read-only memory";
+ else if (is_el1_instruction_abort(esr))
+ msg = "execute from non-executable memory";
else
msg = "read from unreadable memory";
} else if (addr < PAGE_SIZE) {
msg = "NULL pointer dereference";
} else {
+ if (kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs))
+ return;
+
msg = "paging request";
}
die_kernel_fault(msg, addr, esr, regs);
}
-static void __do_user_fault(struct siginfo *info, unsigned int esr)
+static void set_thread_esr(unsigned long address, unsigned int esr)
{
- current->thread.fault_address = (unsigned long)info->si_addr;
+ current->thread.fault_address = address;
/*
* If the faulting address is in the kernel, we must sanitize the ESR.
@@ -365,25 +457,22 @@
}
current->thread.fault_code = esr;
- arm64_force_sig_info(info, esr_to_fault_info(esr)->name, current);
}
-static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static void do_bad_area(unsigned long far, unsigned int esr,
+ struct pt_regs *regs)
{
+ unsigned long addr = untagged_addr(far);
+
/*
* If we are in kernel mode at this point, we have no context to
* handle this fault with.
*/
if (user_mode(regs)) {
const struct fault_info *inf = esr_to_fault_info(esr);
- struct siginfo si;
- clear_siginfo(&si);
- si.si_signo = inf->sig;
- si.si_code = inf->code;
- si.si_addr = (void __user *)addr;
-
- __do_user_fault(&si, esr);
+ set_thread_esr(addr, esr);
+ arm64_force_sig_fault(inf->sig, inf->code, far, inf->name);
} else {
__do_kernel_fault(addr, esr, regs);
}
@@ -392,41 +481,32 @@
#define VM_FAULT_BADMAP 0x010000
#define VM_FAULT_BADACCESS 0x020000
-static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int mm_flags, unsigned long vm_flags,
- struct task_struct *tsk)
+static int __do_page_fault(struct vm_area_struct *vma, unsigned long addr,
+ unsigned int mm_flags, unsigned long vm_flags,
+ struct pt_regs *regs)
{
- struct vm_area_struct *vma;
- vm_fault_t fault;
- vma = find_vma(mm, addr);
- fault = VM_FAULT_BADMAP;
if (unlikely(!vma))
- goto out;
- if (unlikely(vma->vm_start > addr))
- goto check_stack;
+ return VM_FAULT_BADMAP;
/*
* Ok, we have a good vm_area for this memory access, so we can handle
* it.
*/
-good_area:
+ if (unlikely(vma->vm_start > addr)) {
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ return VM_FAULT_BADMAP;
+ if (expand_stack(vma, addr))
+ return VM_FAULT_BADMAP;
+ }
+
/*
* Check that the permissions on the VMA allow for the fault which
* occurred.
*/
- if (!(vma->vm_flags & vm_flags)) {
- fault = VM_FAULT_BADACCESS;
- goto out;
- }
-
- return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags);
-
-check_stack:
- if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
- goto good_area;
-out:
- return fault;
+ if (!(vma->vm_flags & vm_flags))
+ return VM_FAULT_BADACCESS;
+ return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags, regs);
}
static bool is_el0_instruction_abort(unsigned int esr)
@@ -434,21 +514,28 @@
return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
}
-static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
+/*
+ * Note: not valid for EL1 DC IVAC, but we never use that such that it
+ * should fault. EL0 cannot issue DC IVAC (undef).
+ */
+static bool is_write_abort(unsigned int esr)
+{
+ return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
+}
+
+static int __kprobes do_page_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
- struct task_struct *tsk;
- struct mm_struct *mm;
- struct siginfo si;
- vm_fault_t fault, major = 0;
- unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
- unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+ const struct fault_info *inf;
+ struct mm_struct *mm = current->mm;
+ vm_fault_t fault;
+ unsigned long vm_flags = VM_ACCESS_FLAGS;
+ unsigned int mm_flags = FAULT_FLAG_DEFAULT;
+ struct vm_area_struct *vma = NULL;
+ unsigned long addr = untagged_addr(far);
- if (notify_page_fault(regs, esr))
+ if (kprobe_page_fault(regs, esr))
return 0;
-
- tsk = current;
- mm = tsk->mm;
/*
* If we're in an interrupt or have no user context, we must not take
@@ -462,12 +549,13 @@
if (is_el0_instruction_abort(esr)) {
vm_flags = VM_EXEC;
- } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) {
+ mm_flags |= FAULT_FLAG_INSTRUCTION;
+ } else if (is_write_abort(esr)) {
vm_flags = VM_WRITE;
mm_flags |= FAULT_FLAG_WRITE;
}
- if (is_ttbr0_addr(addr) && is_el1_permission_fault(esr, regs, addr)) {
+ if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) {
/* regs->orig_addr_limit may be 0 if we entered from EL0 */
if (regs->orig_addr_limit == KERNEL_DS)
die_kernel_fault("access to user memory with fs=KERNEL_DS",
@@ -485,15 +573,23 @@
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
/*
+ * let's try a speculative page fault without grabbing the
+ * mmap_sem.
+ */
+ fault = handle_speculative_fault(mm, addr, mm_flags, &vma, regs);
+ if (fault != VM_FAULT_RETRY)
+ goto done;
+
+ /*
* As per x86, we may deadlock here. However, since the kernel only
* validly references user space from well defined areas of the code,
* we can bug out early if this is from code which shouldn't.
*/
- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!mmap_read_trylock(mm)) {
if (!user_mode(regs) && !search_exception_tables(regs->pc))
goto no_context;
retry:
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
} else {
/*
* The above down_read_trylock() might have succeeded in which
@@ -501,62 +597,47 @@
*/
might_sleep();
#ifdef CONFIG_DEBUG_VM
- if (!user_mode(regs) && !search_exception_tables(regs->pc))
+ if (!user_mode(regs) && !search_exception_tables(regs->pc)) {
+ mmap_read_unlock(mm);
goto no_context;
+ }
#endif
}
- fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
- major |= fault & VM_FAULT_MAJOR;
+ if (!vma || !can_reuse_spf_vma(vma, addr))
+ vma = find_vma(mm, addr);
+ fault = __do_page_fault(vma, addr, mm_flags, vm_flags, regs);
+
+ /* Quick path to respond to signals */
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return 0;
+ }
if (fault & VM_FAULT_RETRY) {
- /*
- * If we need to retry but a fatal signal is pending,
- * handle the signal first. We do not need to release
- * the mmap_sem because it would already be released
- * in __lock_page_or_retry in mm/filemap.c.
- */
- if (fatal_signal_pending(current)) {
- if (!user_mode(regs))
- goto no_context;
- return 0;
- }
-
- /*
- * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
- * starvation.
- */
if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
- mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
mm_flags |= FAULT_FLAG_TRIED;
+
+ /*
+ * Do not try to reuse this vma and fetch it
+ * again since we will release the mmap_sem.
+ */
+ vma = NULL;
+
goto retry;
}
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
+
+done:
/*
* Handle the "normal" (no error) case first.
*/
if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
- VM_FAULT_BADACCESS)))) {
- /*
- * Major/minor page fault accounting is only done
- * once. If we go through a retry, it is extremely
- * likely that the page will be found in page cache at
- * that point.
- */
- if (major) {
- tsk->maj_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
- addr);
- } else {
- tsk->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
- addr);
- }
-
+ VM_FAULT_BADACCESS))))
return 0;
- }
/*
* If we are in kernel mode at this point, we have no context to
@@ -575,37 +656,32 @@
return 0;
}
- clear_siginfo(&si);
- si.si_addr = (void __user *)addr;
-
+ inf = esr_to_fault_info(esr);
+ set_thread_esr(addr, esr);
if (fault & VM_FAULT_SIGBUS) {
/*
* We had some memory, but were unable to successfully fix up
* this page fault.
*/
- si.si_signo = SIGBUS;
- si.si_code = BUS_ADRERR;
- } else if (fault & VM_FAULT_HWPOISON_LARGE) {
- unsigned int hindex = VM_FAULT_GET_HINDEX(fault);
+ arm64_force_sig_fault(SIGBUS, BUS_ADRERR, far, inf->name);
+ } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
+ unsigned int lsb;
- si.si_signo = SIGBUS;
- si.si_code = BUS_MCEERR_AR;
- si.si_addr_lsb = hstate_index_to_shift(hindex);
- } else if (fault & VM_FAULT_HWPOISON) {
- si.si_signo = SIGBUS;
- si.si_code = BUS_MCEERR_AR;
- si.si_addr_lsb = PAGE_SHIFT;
+ lsb = PAGE_SHIFT;
+ if (fault & VM_FAULT_HWPOISON_LARGE)
+ lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+
+ arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
* map.
*/
- si.si_signo = SIGSEGV;
- si.si_code = fault == VM_FAULT_BADACCESS ?
- SEGV_ACCERR : SEGV_MAPERR;
+ arm64_force_sig_fault(SIGSEGV,
+ fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
+ far, inf->name);
}
- __do_user_fault(&si, esr);
return 0;
no_context:
@@ -613,81 +689,84 @@
return 0;
}
-int __weak do_tlb_conf_fault(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
-{
- return 1; /* do_bad default */
-}
-
-int (*do_tlb_conf_fault_cb)(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
- = do_tlb_conf_fault; /* initialization saves us a branch */
-EXPORT_SYMBOL_GPL(do_tlb_conf_fault_cb);
-
-static int _do_tlb_conf_fault(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
-{
- return (*do_tlb_conf_fault_cb)(addr, esr, regs);
-}
-
-static int __kprobes do_translation_fault(unsigned long addr,
+static int __kprobes do_translation_fault(unsigned long far,
unsigned int esr,
struct pt_regs *regs)
{
- if (is_ttbr0_addr(addr))
- return do_page_fault(addr, esr, regs);
+ unsigned long addr = untagged_addr(far);
- do_bad_area(addr, esr, regs);
+ if (is_ttbr0_addr(addr))
+ return do_page_fault(far, esr, regs);
+
+ do_bad_area(far, esr, regs);
return 0;
}
-static int do_alignment_fault(unsigned long addr, unsigned int esr,
+#ifdef CONFIG_ROCKCHIP_ARM64_ALIGN_FAULT_FIX
+extern int alignment_fixup_helper(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs);
+#endif
+static int do_alignment_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
- do_bad_area(addr, esr, regs);
+#ifdef CONFIG_ROCKCHIP_ARM64_ALIGN_FAULT_FIX
+ if (!alignment_fixup_helper(far, esr, regs))
+ return 0;
+#endif
+ do_bad_area(far, esr, regs);
return 0;
}
-static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static int do_bad(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
- return 1; /* "fault" */
+ unsigned long addr = untagged_addr(far);
+ int ret = 1;
+
+ trace_android_vh_handle_tlb_conf(addr, esr, &ret);
+ return ret;
}
-static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static int do_sea(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
- struct siginfo info;
const struct fault_info *inf;
+ unsigned long siaddr;
inf = esr_to_fault_info(esr);
- /*
- * Synchronous aborts may interrupt code which had interrupts masked.
- * Before calling out into the wider kernel tell the interested
- * subsystems.
- */
- if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
- if (interrupts_enabled(regs))
- nmi_enter();
-
- ghes_notify_sea();
-
- if (interrupts_enabled(regs))
- nmi_exit();
+ if (user_mode(regs) && apei_claim_sea(regs) == 0) {
+ /*
+ * APEI claimed this as a firmware-first notification.
+ * Some processing deferred to task_work before ret_to_user().
+ */
+ return 0;
}
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- if (esr & ESR_ELx_FnV)
- info.si_addr = NULL;
- else
- info.si_addr = (void __user *)addr;
- arm64_notify_die(inf->name, regs, &info, esr);
+ if (esr & ESR_ELx_FnV) {
+ siaddr = 0;
+ } else {
+ /*
+ * The architecture specifies that the tag bits of FAR_EL1 are
+ * UNKNOWN for synchronous external aborts. Mask them out now
+ * so that userspace doesn't see them.
+ */
+ siaddr = untagged_addr(far);
+ }
+ trace_android_rvh_do_sea(regs, esr, siaddr, inf->name);
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
+ return 0;
+}
+
+static int do_tag_check_fault(unsigned long far, unsigned int esr,
+ struct pt_regs *regs)
+{
+ /*
+ * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN
+ * for tag check faults. Set them to corresponding bits in the untagged
+ * address.
+ */
+ far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK);
+ do_bad_area(far, esr, regs);
return 0;
}
@@ -709,7 +788,7 @@
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 17" },
+ { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 18" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 19" },
{ do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" },
@@ -740,7 +819,7 @@
{ do_bad, SIGKILL, SI_KERNEL, "unknown 45" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 46" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 47" },
- { _do_tlb_conf_fault, SIGKILL, SI_KERNEL, "TLB conflict abort" },
+ { do_bad, SIGKILL, SI_KERNEL, "TLB conflict abort" },
{ do_bad, SIGKILL, SI_KERNEL, "Unsupported atomic hardware update fault" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 50" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 51" },
@@ -758,76 +837,45 @@
{ do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
};
-int handle_guest_sea(phys_addr_t addr, unsigned int esr)
-{
- return ghes_notify_sea();
-}
-
-asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
- struct pt_regs *regs)
+void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
const struct fault_info *inf = esr_to_fault_info(esr);
- struct siginfo info;
+ unsigned long addr = untagged_addr(far);
- if (!inf->fn(addr, esr, regs))
+ if (!inf->fn(far, esr, regs))
return;
if (!user_mode(regs)) {
pr_alert("Unhandled fault at 0x%016lx\n", addr);
+ trace_android_rvh_do_mem_abort(regs, esr, addr, inf->name);
mem_abort_decode(esr);
show_pte(addr);
}
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)addr;
- arm64_notify_die(inf->name, regs, &info, esr);
+ /*
+ * At this point we have an unrecognized fault type whose tag bits may
+ * have been defined as UNKNOWN. Therefore we only expose the untagged
+ * address to the signal handler.
+ */
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, addr, esr);
}
+NOKPROBE_SYMBOL(do_mem_abort);
-asmlinkage void __exception do_el0_irq_bp_hardening(void)
+void do_el0_irq_bp_hardening(void)
{
/* PC has already been checked in entry.S */
arm64_apply_bp_hardening();
}
+NOKPROBE_SYMBOL(do_el0_irq_bp_hardening);
-asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
+void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
- /*
- * We've taken an instruction abort from userspace and not yet
- * re-enabled IRQs. If the address is a kernel address, apply
- * BP hardening prior to enabling IRQs and pre-emption.
- */
- if (!is_ttbr0_addr(addr))
- arm64_apply_bp_hardening();
+ trace_android_rvh_do_sp_pc_abort(regs, esr, addr, user_mode(regs));
- local_irq_enable();
- do_mem_abort(addr, esr, regs);
+ arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN,
+ addr, esr);
}
-
-
-asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
-{
- struct siginfo info;
-
- if (user_mode(regs)) {
- if (!is_ttbr0_addr(instruction_pointer(regs)))
- arm64_apply_bp_hardening();
- local_irq_enable();
- }
-
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRALN;
- info.si_addr = (void __user *)addr;
- arm64_notify_die("SP/PC alignment exception", regs, &info, esr);
-}
+NOKPROBE_SYMBOL(do_sp_pc_abort);
int __init early_brk64(unsigned long addr, unsigned int esr,
struct pt_regs *regs);
@@ -860,11 +908,32 @@
debug_fault_info[nr].name = name;
}
+/*
+ * In debug exception context, we explicitly disable preemption despite
+ * having interrupts disabled.
+ * This serves two purposes: it makes it much less likely that we would
+ * accidentally schedule in exception context and it will force a warning
+ * if we somehow manage to schedule by accident.
+ */
+static void debug_exception_enter(struct pt_regs *regs)
+{
+ preempt_disable();
+
+ /* This code is a bit fragile. Test it. */
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work");
+}
+NOKPROBE_SYMBOL(debug_exception_enter);
+
+static void debug_exception_exit(struct pt_regs *regs)
+{
+ preempt_enable_no_resched();
+}
+NOKPROBE_SYMBOL(debug_exception_exit);
+
#ifdef CONFIG_ARM64_ERRATUM_1463225
DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
-static int __exception
-cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
+static int cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
{
if (user_mode(regs))
return 0;
@@ -883,65 +952,57 @@
return 1;
}
#else
-static int __exception
-cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
+static int cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
{
return 0;
}
#endif /* CONFIG_ARM64_ERRATUM_1463225 */
+NOKPROBE_SYMBOL(cortex_a76_erratum_1463225_debug_handler);
-asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint,
- unsigned int esr,
- struct pt_regs *regs)
+void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
+ struct pt_regs *regs)
{
- const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
+ const struct fault_info *inf = esr_to_debug_fault_info(esr);
unsigned long pc = instruction_pointer(regs);
- int rv;
if (cortex_a76_erratum_1463225_debug_handler(regs))
- return 0;
+ return;
- /*
- * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
- * already disabled to preserve the last enabled/disabled addresses.
- */
- if (interrupts_enabled(regs))
- trace_hardirqs_off();
+ debug_exception_enter(regs);
if (user_mode(regs) && !is_ttbr0_addr(pc))
arm64_apply_bp_hardening();
- if (!inf->fn(addr_if_watchpoint, esr, regs)) {
- rv = 1;
- } else {
- struct siginfo info;
-
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)pc;
- arm64_notify_die(inf->name, regs, &info, esr);
- rv = 0;
+ if (inf->fn(addr_if_watchpoint, esr, regs)) {
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, pc, esr);
}
- if (interrupts_enabled(regs))
- trace_hardirqs_on();
-
- return rv;
+ debug_exception_exit(regs);
}
NOKPROBE_SYMBOL(do_debug_exception);
-#ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
+/*
+ * Used during anonymous page fault handling.
+ */
+struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
+ unsigned long vaddr)
{
- /*
- * We modify PSTATE. This won't work from irq context as the PSTATE
- * is discarded once we return from the exception.
- */
- WARN_ON_ONCE(in_interrupt());
+ gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO | __GFP_CMA;
- sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
- asm(SET_PSTATE_PAN(1));
+ /*
+ * If the page is mapped with PROT_MTE, initialise the tags at the
+ * point of allocation and page zeroing as this is usually faster than
+ * separate DC ZVA and STGM.
+ */
+ if (vma->vm_flags & VM_MTE)
+ flags |= __GFP_ZEROTAGS;
+
+ return alloc_page_vma(flags, vma, vaddr);
}
-#endif /* CONFIG_ARM64_PAN */
+
+void tag_clear_highpage(struct page *page)
+{
+ mte_zero_clear_page_tags(page_address(page));
+ page_kasan_tag_reset(page);
+ set_bit(PG_mte_tagged, &page->flags);
+}
--
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