kernel/drivers/misc/lkdtm/powerpc.c
2024-07-22 17:22:30 +08:00

121 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "lkdtm.h"
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/mmu.h>
/* Inserts new slb entries */
static void insert_slb_entry(unsigned long p, int ssize, int page_size)
{
unsigned long flags;
flags = SLB_VSID_KERNEL | mmu_psize_defs[page_size].sllp;
preempt_disable();
asm volatile("slbmte %0,%1" :
: "r" (mk_vsid_data(p, ssize, flags)),
"r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED))
: "memory");
asm volatile("slbmte %0,%1" :
: "r" (mk_vsid_data(p, ssize, flags)),
"r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED + 1))
: "memory");
preempt_enable();
}
/* Inject slb multihit on vmalloc-ed address i.e 0xD00... */
static int inject_vmalloc_slb_multihit(void)
{
char *p;
p = vmalloc(PAGE_SIZE);
if (!p)
return -ENOMEM;
insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_vmalloc_psize);
/*
* This triggers exception, If handled correctly we must recover
* from this error.
*/
p[0] = '!';
vfree(p);
return 0;
}
/* Inject slb multihit on kmalloc-ed address i.e 0xC00... */
static int inject_kmalloc_slb_multihit(void)
{
char *p;
p = kmalloc(2048, GFP_KERNEL);
if (!p)
return -ENOMEM;
insert_slb_entry((unsigned long)p, MMU_SEGSIZE_1T, mmu_linear_psize);
/*
* This triggers exception, If handled correctly we must recover
* from this error.
*/
p[0] = '!';
kfree(p);
return 0;
}
/*
* Few initial SLB entries are bolted. Add a test to inject
* multihit in bolted entry 0.
*/
static void insert_dup_slb_entry_0(void)
{
unsigned long test_address = PAGE_OFFSET, *test_ptr;
unsigned long esid, vsid;
unsigned long i = 0;
test_ptr = (unsigned long *)test_address;
preempt_disable();
asm volatile("slbmfee %0,%1" : "=r" (esid) : "r" (i));
asm volatile("slbmfev %0,%1" : "=r" (vsid) : "r" (i));
/* for i !=0 we would need to mask out the old entry number */
asm volatile("slbmte %0,%1" :
: "r" (vsid),
"r" (esid | SLB_NUM_BOLTED)
: "memory");
asm volatile("slbmfee %0,%1" : "=r" (esid) : "r" (i));
asm volatile("slbmfev %0,%1" : "=r" (vsid) : "r" (i));
/* for i !=0 we would need to mask out the old entry number */
asm volatile("slbmte %0,%1" :
: "r" (vsid),
"r" (esid | (SLB_NUM_BOLTED + 1))
: "memory");
pr_info("%s accessing test address 0x%lx: 0x%lx\n",
__func__, test_address, *test_ptr);
preempt_enable();
}
void lkdtm_PPC_SLB_MULTIHIT(void)
{
if (!radix_enabled()) {
pr_info("Injecting SLB multihit errors\n");
/*
* These need not be separate tests, And they do pretty
* much same thing. In any case we must recover from the
* errors introduced by these functions, machine would not
* survive these tests in case of failure to handle.
*/
inject_vmalloc_slb_multihit();
inject_kmalloc_slb_multihit();
insert_dup_slb_entry_0();
pr_info("Recovered from SLB multihit errors\n");
} else {
pr_err("XFAIL: This test is for ppc64 and with hash mode MMU only\n");
}
}