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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/alpha/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/alpha/mm/fault.c')
-rw-r--r--arch/alpha/mm/fault.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
new file mode 100644
index 000000000..a9816bbc9
--- /dev/null
+++ b/arch/alpha/mm/fault.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/alpha/mm/fault.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ */
+
+#include <linux/sched/signal.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/io.h>
+
+#define __EXTERN_INLINE inline
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#undef __EXTERN_INLINE
+
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+#include <linux/perf_event.h>
+
+extern void die_if_kernel(char *,struct pt_regs *,long, unsigned long *);
+
+
+/*
+ * Force a new ASN for a task.
+ */
+
+#ifndef CONFIG_SMP
+unsigned long last_asn = ASN_FIRST_VERSION;
+#endif
+
+void
+__load_new_mm_context(struct mm_struct *next_mm)
+{
+ unsigned long mmc;
+ struct pcb_struct *pcb;
+
+ mmc = __get_new_mm_context(next_mm, smp_processor_id());
+ next_mm->context[smp_processor_id()] = mmc;
+
+ pcb = &current_thread_info()->pcb;
+ pcb->asn = mmc & HARDWARE_ASN_MASK;
+ pcb->ptbr = ((unsigned long) next_mm->pgd - IDENT_ADDR) >> PAGE_SHIFT;
+
+ __reload_thread(pcb);
+}
+
+
+/*
+ * This routine handles page faults. It determines the address,
+ * and the problem, and then passes it off to handle_mm_fault().
+ *
+ * mmcsr:
+ * 0 = translation not valid
+ * 1 = access violation
+ * 2 = fault-on-read
+ * 3 = fault-on-execute
+ * 4 = fault-on-write
+ *
+ * cause:
+ * -1 = instruction fetch
+ * 0 = load
+ * 1 = store
+ *
+ * Registers $9 through $15 are saved in a block just prior to `regs' and
+ * are saved and restored around the call to allow exception code to
+ * modify them.
+ */
+
+/* Macro for exception fixup code to access integer registers. */
+#define dpf_reg(r) \
+ (((unsigned long *)regs)[(r) <= 8 ? (r) : (r) <= 15 ? (r)-17 : \
+ (r) <= 18 ? (r)+11 : (r)-10])
+
+asmlinkage void
+do_page_fault(unsigned long address, unsigned long mmcsr,
+ long cause, struct pt_regs *regs)
+{
+ struct vm_area_struct * vma;
+ struct mm_struct *mm = current->mm;
+ const struct exception_table_entry *fixup;
+ int si_code = SEGV_MAPERR;
+ vm_fault_t fault;
+ unsigned int flags = FAULT_FLAG_DEFAULT;
+
+ /* As of EV6, a load into $31/$f31 is a prefetch, and never faults
+ (or is suppressed by the PALcode). Support that for older CPUs
+ by ignoring such an instruction. */
+ if (cause == 0) {
+ unsigned int insn;
+ __get_user(insn, (unsigned int __user *)regs->pc);
+ if ((insn >> 21 & 0x1f) == 0x1f &&
+ /* ldq ldl ldt lds ldg ldf ldwu ldbu */
+ (1ul << (insn >> 26) & 0x30f00001400ul)) {
+ regs->pc += 4;
+ return;
+ }
+ }
+
+ /* If we're in an interrupt context, or have no user context,
+ we must not take the fault. */
+ if (!mm || faulthandler_disabled())
+ goto no_context;
+
+#ifdef CONFIG_ALPHA_LARGE_VMALLOC
+ if (address >= TASK_SIZE)
+ goto vmalloc_fault;
+#endif
+ 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 (cause < 0) {
+ if (!(vma->vm_flags & VM_EXEC))
+ goto bad_area;
+ } else if (!cause) {
+ /* Allow reads even for write-only mappings */
+ if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
+ goto bad_area;
+ } else {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
+ }
+
+ /* 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:
+ if (user_mode(regs))
+ goto do_sigsegv;
+
+ no_context:
+ /* Are we prepared to handle this fault as an exception? */
+ if ((fixup = search_exception_tables(regs->pc)) != 0) {
+ unsigned long newpc;
+ newpc = fixup_exception(dpf_reg, fixup, regs->pc);
+ regs->pc = newpc;
+ return;
+ }
+
+ /* Oops. The kernel tried to access some bad page. We'll have to
+ terminate things with extreme prejudice. */
+ printk(KERN_ALERT "Unable to handle kernel paging request at "
+ "virtual address %016lx\n", address);
+ die_if_kernel("Oops", regs, cause, (unsigned long*)regs - 16);
+ make_task_dead(SIGKILL);
+
+ /* We ran out of memory, or some other thing happened to us that
+ made us unable to handle the page fault gracefully. */
+ out_of_memory:
+ mmap_read_unlock(mm);
+ if (!user_mode(regs))
+ goto no_context;
+ pagefault_out_of_memory();
+ return;
+
+ do_sigbus:
+ mmap_read_unlock(mm);
+ /* Send a sigbus, regardless of whether we were in kernel
+ or user mode. */
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) address);
+ if (!user_mode(regs))
+ goto no_context;
+ return;
+
+ do_sigsegv:
+ force_sig_fault(SIGSEGV, si_code, (void __user *) address);
+ return;
+
+#ifdef CONFIG_ALPHA_LARGE_VMALLOC
+ vmalloc_fault:
+ if (user_mode(regs))
+ goto do_sigsegv;
+ else {
+ /* Synchronize this task's top level page-table
+ with the "reference" page table from init. */
+ long index = pgd_index(address);
+ pgd_t *pgd, *pgd_k;
+
+ pgd = current->active_mm->pgd + index;
+ pgd_k = swapper_pg_dir + index;
+ if (!pgd_present(*pgd) && pgd_present(*pgd_k)) {
+ pgd_val(*pgd) = pgd_val(*pgd_k);
+ return;
+ }
+ goto no_context;
+ }
+#endif
+}