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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /arch/mips/mm/fault.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'arch/mips/mm/fault.c')
-rw-r--r--arch/mips/mm/fault.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
new file mode 100644
index 000000000..37fedeaca
--- /dev/null
+++ b/arch/mips/mm/fault.c
@@ -0,0 +1,333 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1995 - 2000 by Ralf Baechle
+ */
+#include <linux/context_tracking.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/ratelimit.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kprobes.h>
+#include <linux/perf_event.h>
+#include <linux/uaccess.h>
+
+#include <asm/branch.h>
+#include <asm/mmu_context.h>
+#include <asm/ptrace.h>
+#include <asm/highmem.h> /* For VMALLOC_END */
+#include <asm/traps.h>
+#include <linux/kdebug.h>
+
+int show_unhandled_signals = 1;
+
+/*
+ * This routine handles page faults. It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+static void __do_page_fault(struct pt_regs *regs, unsigned long write,
+ unsigned long address)
+{
+ struct vm_area_struct * vma = NULL;
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ const int field = sizeof(unsigned long) * 2;
+ int si_code;
+ vm_fault_t fault;
+ unsigned int flags = FAULT_FLAG_DEFAULT;
+
+ static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+#if 0
+ printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(),
+ current->comm, current->pid, field, address, write,
+ field, regs->cp0_epc);
+#endif
+
+#ifdef CONFIG_KPROBES
+ /*
+ * This is to notify the fault handler of the kprobes.
+ */
+ if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
+ current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
+ return;
+#endif
+
+ si_code = SEGV_MAPERR;
+
+ /*
+ * We fault-in kernel-space virtual memory on-demand. The
+ * 'reference' page table is init_mm.pgd.
+ *
+ * NOTE! We MUST NOT take any locks for this case. We may
+ * be in an interrupt or a critical region, and should
+ * only copy the information from the master page table,
+ * nothing more.
+ */
+#ifdef CONFIG_64BIT
+# define VMALLOC_FAULT_TARGET no_context
+#else
+# define VMALLOC_FAULT_TARGET vmalloc_fault
+#endif
+
+ if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
+ goto VMALLOC_FAULT_TARGET;
+#ifdef MODULES_VADDR
+ if (unlikely(address >= MODULES_VADDR && address < MODULES_END))
+ goto VMALLOC_FAULT_TARGET;
+#endif
+
+ /*
+ * If we're in an interrupt or have no user
+ * context, we must not take the fault..
+ */
+ if (faulthandler_disabled() || !mm)
+ goto bad_area_nosemaphore;
+
+ if (user_mode(regs))
+ flags |= FAULT_FLAG_USER;
+
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+retry:
+ vma = lock_mm_and_find_vma(mm, address, regs);
+ if (!vma)
+ goto bad_area_nosemaphore;
+/*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+ si_code = SEGV_ACCERR;
+
+ if (write) {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
+ } else {
+ if (cpu_has_rixi) {
+ if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) {
+#if 0
+ pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] XI violation\n",
+ raw_smp_processor_id(),
+ current->comm, current->pid,
+ field, address, write,
+ field, regs->cp0_epc);
+#endif
+ goto bad_area;
+ }
+ if (!(vma->vm_flags & VM_READ) &&
+ exception_epc(regs) != address) {
+#if 0
+ pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] RI violation\n",
+ raw_smp_processor_id(),
+ current->comm, current->pid,
+ field, address, write,
+ field, regs->cp0_epc);
+#endif
+ goto bad_area;
+ }
+ } else {
+ if (unlikely(!vma_is_accessible(vma)))
+ goto bad_area;
+ }
+ }
+
+ /*
+ * If for any reason at all we couldn't handle the fault,
+ * make sure we exit gracefully rather than endlessly redo
+ * the fault.
+ */
+ fault = handle_mm_fault(vma, address, flags, regs);
+
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return;
+ }
+
+ /* The fault is fully completed (including releasing mmap lock) */
+ if (fault & VM_FAULT_COMPLETED)
+ return;
+
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGSEGV)
+ goto bad_area;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
+ }
+
+ if (fault & VM_FAULT_RETRY) {
+ flags |= FAULT_FLAG_TRIED;
+
+ /*
+ * No need to mmap_read_unlock(mm) as we would
+ * have already released it in __lock_page_or_retry
+ * in mm/filemap.c.
+ */
+
+ goto retry;
+ }
+
+ mmap_read_unlock(mm);
+ return;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+ mmap_read_unlock(mm);
+
+bad_area_nosemaphore:
+ /* User mode accesses just cause a SIGSEGV */
+ if (user_mode(regs)) {
+ tsk->thread.cp0_badvaddr = address;
+ tsk->thread.error_code = write;
+ if (show_unhandled_signals &&
+ unhandled_signal(tsk, SIGSEGV) &&
+ __ratelimit(&ratelimit_state)) {
+ pr_info("do_page_fault(): sending SIGSEGV to %s for invalid %s %0*lx\n",
+ tsk->comm,
+ write ? "write access to" : "read access from",
+ field, address);
+ pr_info("epc = %0*lx in", field,
+ (unsigned long) regs->cp0_epc);
+ print_vma_addr(KERN_CONT " ", regs->cp0_epc);
+ pr_cont("\n");
+ pr_info("ra = %0*lx in", field,
+ (unsigned long) regs->regs[31]);
+ print_vma_addr(KERN_CONT " ", regs->regs[31]);
+ pr_cont("\n");
+ }
+ current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
+ force_sig_fault(SIGSEGV, si_code, (void __user *)address);
+ return;
+ }
+
+no_context:
+ /* Are we prepared to handle this kernel fault? */
+ if (fixup_exception(regs)) {
+ current->thread.cp0_baduaddr = address;
+ return;
+ }
+
+ /*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+ bust_spinlocks(1);
+
+ printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at "
+ "virtual address %0*lx, epc == %0*lx, ra == %0*lx\n",
+ raw_smp_processor_id(), field, address, field, regs->cp0_epc,
+ field, regs->regs[31]);
+ die("Oops", regs);
+
+out_of_memory:
+ /*
+ * 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).
+ */
+ mmap_read_unlock(mm);
+ if (!user_mode(regs))
+ goto no_context;
+ pagefault_out_of_memory();
+ return;
+
+do_sigbus:
+ mmap_read_unlock(mm);
+
+ /* Kernel mode? Handle exceptions or die */
+ if (!user_mode(regs))
+ goto no_context;
+
+ /*
+ * Send a sigbus, regardless of whether we were in kernel
+ * or user mode.
+ */
+#if 0
+ printk("do_page_fault() #3: sending SIGBUS to %s for "
+ "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
+ tsk->comm,
+ write ? "write access to" : "read access from",
+ field, address,
+ field, (unsigned long) regs->cp0_epc,
+ field, (unsigned long) regs->regs[31]);
+#endif
+ current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
+ tsk->thread.cp0_badvaddr = address;
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
+
+ return;
+#ifndef CONFIG_64BIT
+vmalloc_fault:
+ {
+ /*
+ * Synchronize this task's top level page-table
+ * with the 'reference' page table.
+ *
+ * Do _not_ use "tsk" here. We might be inside
+ * an interrupt in the middle of a task switch..
+ */
+ int offset = pgd_index(address);
+ pgd_t *pgd, *pgd_k;
+ p4d_t *p4d, *p4d_k;
+ pud_t *pud, *pud_k;
+ pmd_t *pmd, *pmd_k;
+ pte_t *pte_k;
+
+ pgd = (pgd_t *) pgd_current[raw_smp_processor_id()] + offset;
+ pgd_k = init_mm.pgd + offset;
+
+ if (!pgd_present(*pgd_k))
+ goto no_context;
+ set_pgd(pgd, *pgd_k);
+
+ p4d = p4d_offset(pgd, address);
+ p4d_k = p4d_offset(pgd_k, address);
+ if (!p4d_present(*p4d_k))
+ goto no_context;
+
+ pud = pud_offset(p4d, address);
+ pud_k = pud_offset(p4d_k, address);
+ if (!pud_present(*pud_k))
+ goto no_context;
+
+ pmd = pmd_offset(pud, address);
+ pmd_k = pmd_offset(pud_k, address);
+ if (!pmd_present(*pmd_k))
+ goto no_context;
+ set_pmd(pmd, *pmd_k);
+
+ pte_k = pte_offset_kernel(pmd_k, address);
+ if (!pte_present(*pte_k))
+ goto no_context;
+ return;
+ }
+#endif
+}
+NOKPROBE_SYMBOL(__do_page_fault);
+
+asmlinkage void do_page_fault(struct pt_regs *regs,
+ unsigned long write, unsigned long address)
+{
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
+ __do_page_fault(regs, write, address);
+ exception_exit(prev_state);
+}
+NOKPROBE_SYMBOL(do_page_fault);