arch/hexagon/mm/vm_fault.c

Source file repositories/reference/linux-study-clean/arch/hexagon/mm/vm_fault.c

File Facts

System
Linux kernel
Corpus path
arch/hexagon/mm/vm_fault.c
Extension
.c
Size
3856 bytes
Lines
178
Domain
Architecture Layer
Bucket
arch/hexagon
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

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;

	/* The most common case -- we are done. */
	if (likely(!(fault & VM_FAULT_ERROR))) {
		if (fault & VM_FAULT_RETRY) {
			flags |= FAULT_FLAG_TRIED;
			goto retry;
		}

		mmap_read_unlock(mm);
		return;
	}

	mmap_read_unlock(mm);

	/* Handle copyin/out exception cases */
	if (!user_mode(regs))
		goto no_context;

	if (fault & VM_FAULT_OOM) {
		pagefault_out_of_memory();
		return;
	}

	/* User-mode address is in the memory map, but we are
	 * unable to fix up the page fault.
	 */
	if (fault & VM_FAULT_SIGBUS) {
		si_signo = SIGBUS;
		si_code = BUS_ADRERR;
	}
	/* Address is not in the memory map */
	else {
		si_signo = SIGSEGV;
		si_code  = SEGV_ACCERR;
	}
	force_sig_fault(si_signo, si_code, (void __user *)address);
	return;

bad_area:
	mmap_read_unlock(mm);

bad_area_nosemaphore:
	if (user_mode(regs)) {
		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
		return;
	}
	/* Kernel-mode fault falls through */

no_context:
	fixup = search_exception_tables(pt_elr(regs));
	if (fixup) {
		pt_set_elr(regs, fixup->fixup);
		return;
	}

	/* Things are looking very, very bad now */
	bust_spinlocks(1);
	printk(KERN_EMERG "Unable to handle kernel paging request at "
		"virtual address 0x%08lx, regs %p\n", address, regs);
	die("Bad Kernel VA", regs, SIGKILL);
}


void read_protection_fault(struct pt_regs *regs)
{
	unsigned long badvadr = pt_badva(regs);

	do_page_fault(badvadr, FLT_LOAD, regs);
}

void write_protection_fault(struct pt_regs *regs)
{
	unsigned long badvadr = pt_badva(regs);

	do_page_fault(badvadr, FLT_STORE, regs);
}

void execute_protection_fault(struct pt_regs *regs)
{

Annotation

Implementation Notes