cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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powerpc.c (3180B)

      1// SPDX-License-Identifier: GPL-2.0
      2
      3#include "lkdtm.h"
      4#include <linux/slab.h>
      5#include <linux/vmalloc.h>
      6#include <asm/mmu.h>
      7
      8/* Inserts new slb entries */
      9static void insert_slb_entry(unsigned long p, int ssize, int page_size)
     10{
     11	unsigned long flags;
     12
     13	flags = SLB_VSID_KERNEL | mmu_psize_defs[page_size].sllp;
     14	preempt_disable();
     15
     16	asm volatile("slbmte %0,%1" :
     17		     : "r" (mk_vsid_data(p, ssize, flags)),
     18		       "r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED))
     19		     : "memory");
     20
     21	asm volatile("slbmte %0,%1" :
     22			: "r" (mk_vsid_data(p, ssize, flags)),
     23			  "r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED + 1))
     24			: "memory");
     25	preempt_enable();
     26}
     27
     28/* Inject slb multihit on vmalloc-ed address i.e 0xD00... */
     29static int inject_vmalloc_slb_multihit(void)
     30{
     31	char *p;
     32
     33	p = vmalloc(PAGE_SIZE);
     34	if (!p)
     35		return -ENOMEM;
     36
     37	insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_vmalloc_psize);
     38	/*
     39	 * This triggers exception, If handled correctly we must recover
     40	 * from this error.
     41	 */
     42	p[0] = '!';
     43	vfree(p);
     44	return 0;
     45}
     46
     47/* Inject slb multihit on kmalloc-ed address i.e 0xC00... */
     48static int inject_kmalloc_slb_multihit(void)
     49{
     50	char *p;
     51
     52	p = kmalloc(2048, GFP_KERNEL);
     53	if (!p)
     54		return -ENOMEM;
     55
     56	insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_linear_psize);
     57	/*
     58	 * This triggers exception, If handled correctly we must recover
     59	 * from this error.
     60	 */
     61	p[0] = '!';
     62	kfree(p);
     63	return 0;
     64}
     65
     66/*
     67 * Few initial SLB entries are bolted. Add a test to inject
     68 * multihit in bolted entry 0.
     69 */
     70static void insert_dup_slb_entry_0(void)
     71{
     72	unsigned long test_address = PAGE_OFFSET, *test_ptr;
     73	unsigned long esid, vsid;
     74	unsigned long i = 0;
     75
     76	test_ptr = (unsigned long *)test_address;
     77	preempt_disable();
     78
     79	asm volatile("slbmfee  %0,%1" : "=r" (esid) : "r" (i));
     80	asm volatile("slbmfev  %0,%1" : "=r" (vsid) : "r" (i));
     81
     82	/* for i !=0 we would need to mask out the old entry number */
     83	asm volatile("slbmte %0,%1" :
     84			: "r" (vsid),
     85			  "r" (esid | SLB_NUM_BOLTED)
     86			: "memory");
     87
     88	asm volatile("slbmfee  %0,%1" : "=r" (esid) : "r" (i));
     89	asm volatile("slbmfev  %0,%1" : "=r" (vsid) : "r" (i));
     90
     91	/* for i !=0 we would need to mask out the old entry number */
     92	asm volatile("slbmte %0,%1" :
     93			: "r" (vsid),
     94			  "r" (esid | (SLB_NUM_BOLTED + 1))
     95			: "memory");
     96
     97	pr_info("%s accessing test address 0x%lx: 0x%lx\n",
     98		__func__, test_address, *test_ptr);
     99
    100	preempt_enable();
    101}
    102
    103static void lkdtm_PPC_SLB_MULTIHIT(void)
    104{
    105	if (!radix_enabled()) {
    106		pr_info("Injecting SLB multihit errors\n");
    107		/*
    108		 * These need not be separate tests, And they do pretty
    109		 * much same thing. In any case we must recover from the
    110		 * errors introduced by these functions, machine would not
    111		 * survive these tests in case of failure to handle.
    112		 */
    113		inject_vmalloc_slb_multihit();
    114		inject_kmalloc_slb_multihit();
    115		insert_dup_slb_entry_0();
    116		pr_info("Recovered from SLB multihit errors\n");
    117	} else {
    118		pr_err("XFAIL: This test is for ppc64 and with hash mode MMU only\n");
    119	}
    120}
    121
    122static struct crashtype crashtypes[] = {
    123	CRASHTYPE(PPC_SLB_MULTIHIT),
    124};
    125
    126struct crashtype_category powerpc_crashtypes = {
    127	.crashtypes = crashtypes,
    128	.len	    = ARRAY_SIZE(crashtypes),
    129};