riscv/mm/fault: Move no context handling to no_context() (cac4d1dc) · Commits · 戴 / test

arch/riscv/mm/fault.c

+52 −31

Original line number	Diff line number	Diff line
		@@ -19,6 +19,24 @@

		#include "../kernel/head.h"

		static inline void no_context(struct pt_regs *regs, unsigned long addr)
		{
		/* Are we prepared to handle this kernel fault? */
		if (fixup_exception(regs))
		return;

		/*
		* Oops. The kernel tried to access some bad page. We'll have to
		* terminate things with extreme prejudice.
		*/
		bust_spinlocks(1);
		pr_alert("Unable to handle kernel %s at virtual address " REG_FMT "\n",
		(addr < PAGE_SIZE) ? "NULL pointer dereference" :
		"paging request", addr);
		die(regs, "Oops");
		do_exit(SIGKILL);
		}

		/*
		* This routine handles page faults. It determines the address and the
		* problem, and then passes it off to one of the appropriate routines.
		@@ -59,8 +77,10 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
		* If we're in an interrupt, have no user context, or are running
		* in an atomic region, then we must not take the fault.
		*/
		if (unlikely(faulthandler_disabled() \|\| !mm))
		goto no_context;
		if (unlikely(faulthandler_disabled() \|\| !mm)) {
		no_context(regs, addr);
		return;
		}

		if (user_mode(regs))
		flags \|= FAULT_FLAG_USER;
		@@ -153,38 +173,29 @@ bad_area:
		return;
		}

		no_context:
		/* Are we prepared to handle this kernel fault? */
		if (fixup_exception(regs))
		no_context(regs, addr);
		return;

		/*
		* Oops. The kernel tried to access some bad page. We'll have to
		* terminate things with extreme prejudice.
		*/
		bust_spinlocks(1);
		pr_alert("Unable to handle kernel %s at virtual address " REG_FMT "\n",
		(addr < PAGE_SIZE) ? "NULL pointer dereference" :
		"paging request", addr);
		die(regs, "Oops");
		do_exit(SIGKILL);

		/*
		* 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).
		*/
		out_of_memory:
		mmap_read_unlock(mm);
		if (!user_mode(regs))
		goto no_context;
		if (!user_mode(regs)) {
		no_context(regs, addr);
		return;
		}
		pagefault_out_of_memory();
		return;

		do_sigbus:
		mmap_read_unlock(mm);
		/* Kernel mode? Handle exceptions or die */
		if (!user_mode(regs))
		goto no_context;
		if (!user_mode(regs)) {
		no_context(regs, addr);
		return;
		}
		do_trap(regs, SIGBUS, BUS_ADRERR, addr);
		return;

		@@ -213,19 +224,25 @@ vmalloc_fault:
		pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
		pgd_k = init_mm.pgd + index;

		if (!pgd_present(*pgd_k))
		goto no_context;
		if (!pgd_present(*pgd_k)) {
		no_context(regs, addr);
		return;
		}
		set_pgd(pgd, *pgd_k);

		p4d = p4d_offset(pgd, addr);
		p4d_k = p4d_offset(pgd_k, addr);
		if (!p4d_present(*p4d_k))
		goto no_context;
		if (!p4d_present(*p4d_k)) {
		no_context(regs, addr);
		return;
		}

		pud = pud_offset(p4d, addr);
		pud_k = pud_offset(p4d_k, addr);
		if (!pud_present(*pud_k))
		goto no_context;
		if (!pud_present(*pud_k)) {
		no_context(regs, addr);
		return;
		}

		/*
		* Since the vmalloc area is global, it is unnecessary
		@@ -233,8 +250,10 @@ vmalloc_fault:
		*/
		pmd = pmd_offset(pud, addr);
		pmd_k = pmd_offset(pud_k, addr);
		if (!pmd_present(*pmd_k))
		goto no_context;
		if (!pmd_present(*pmd_k)) {
		no_context(regs, addr);
		return;
		}
		set_pmd(pmd, *pmd_k);

		/*
		@@ -244,8 +263,10 @@ vmalloc_fault:
		* silently loop forever.
		*/
		pte_k = pte_offset_kernel(pmd_k, addr);
		if (!pte_present(*pte_k))
		goto no_context;
		if (!pte_present(*pte_k)) {
		no_context(regs, addr);
		return;
		}

		/*
		* The kernel assumes that TLBs don't cache invalid

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