forked from mirrors/linux
		
	It's long been annoying that to add a new LKDTM test one had to update lkdtm.h and core.c to get it "registered". Switch to a per-category list and update the crashtype walking code in core.c to handle it. This also means that all the lkdtm_* tests themselves can be static now. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kees Cook <keescook@chromium.org>
		
			
				
	
	
		
			129 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include "lkdtm.h"
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <asm/mmu.h>
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/* Inserts new slb entries */
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static void insert_slb_entry(unsigned long p, int ssize, int page_size)
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{
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	unsigned long flags;
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	flags = SLB_VSID_KERNEL | mmu_psize_defs[page_size].sllp;
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	preempt_disable();
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	asm volatile("slbmte %0,%1" :
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		     : "r" (mk_vsid_data(p, ssize, flags)),
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		       "r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED))
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		     : "memory");
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	asm volatile("slbmte %0,%1" :
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			: "r" (mk_vsid_data(p, ssize, flags)),
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			  "r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED + 1))
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			: "memory");
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	preempt_enable();
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}
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/* Inject slb multihit on vmalloc-ed address i.e 0xD00... */
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static int inject_vmalloc_slb_multihit(void)
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{
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	char *p;
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	p = vmalloc(PAGE_SIZE);
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	if (!p)
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		return -ENOMEM;
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	insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_vmalloc_psize);
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	/*
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	 * This triggers exception, If handled correctly we must recover
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	 * from this error.
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	 */
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	p[0] = '!';
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	vfree(p);
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	return 0;
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}
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/* Inject slb multihit on kmalloc-ed address i.e 0xC00... */
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static int inject_kmalloc_slb_multihit(void)
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{
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	char *p;
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	p = kmalloc(2048, GFP_KERNEL);
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	if (!p)
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		return -ENOMEM;
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	insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_linear_psize);
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	/*
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	 * This triggers exception, If handled correctly we must recover
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	 * from this error.
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	 */
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	p[0] = '!';
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	kfree(p);
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	return 0;
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}
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/*
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 * Few initial SLB entries are bolted. Add a test to inject
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 * multihit in bolted entry 0.
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 */
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static void insert_dup_slb_entry_0(void)
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{
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	unsigned long test_address = PAGE_OFFSET, *test_ptr;
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	unsigned long esid, vsid;
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	unsigned long i = 0;
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	test_ptr = (unsigned long *)test_address;
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	preempt_disable();
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	asm volatile("slbmfee  %0,%1" : "=r" (esid) : "r" (i));
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	asm volatile("slbmfev  %0,%1" : "=r" (vsid) : "r" (i));
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	/* for i !=0 we would need to mask out the old entry number */
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	asm volatile("slbmte %0,%1" :
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			: "r" (vsid),
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			  "r" (esid | SLB_NUM_BOLTED)
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			: "memory");
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	asm volatile("slbmfee  %0,%1" : "=r" (esid) : "r" (i));
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	asm volatile("slbmfev  %0,%1" : "=r" (vsid) : "r" (i));
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	/* for i !=0 we would need to mask out the old entry number */
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	asm volatile("slbmte %0,%1" :
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			: "r" (vsid),
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			  "r" (esid | (SLB_NUM_BOLTED + 1))
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			: "memory");
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	pr_info("%s accessing test address 0x%lx: 0x%lx\n",
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		__func__, test_address, *test_ptr);
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	preempt_enable();
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}
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static void lkdtm_PPC_SLB_MULTIHIT(void)
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{
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	if (!radix_enabled()) {
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		pr_info("Injecting SLB multihit errors\n");
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		/*
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		 * These need not be separate tests, And they do pretty
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		 * much same thing. In any case we must recover from the
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		 * errors introduced by these functions, machine would not
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		 * survive these tests in case of failure to handle.
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		 */
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		inject_vmalloc_slb_multihit();
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		inject_kmalloc_slb_multihit();
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		insert_dup_slb_entry_0();
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		pr_info("Recovered from SLB multihit errors\n");
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	} else {
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		pr_err("XFAIL: This test is for ppc64 and with hash mode MMU only\n");
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	}
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}
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static struct crashtype crashtypes[] = {
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	CRASHTYPE(PPC_SLB_MULTIHIT),
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};
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struct crashtype_category powerpc_crashtypes = {
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	.crashtypes = crashtypes,
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	.len	    = ARRAY_SIZE(crashtypes),
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};
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