drivers/misc/lkdtm/powerpc.c

Source file repositories/reference/linux-study-clean/drivers/misc/lkdtm/powerpc.c

File Facts

System
Linux kernel
Corpus path
drivers/misc/lkdtm/powerpc.c
Extension
.c
Size
4487 bytes
Lines
179
Domain
Driver Families
Bucket
drivers/misc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

#include "lkdtm.h"
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/mmu.h>

#ifdef CONFIG_PPC_64S_HASH_MMU
/* 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");
	isync();

	asm volatile("slbmte %0,%1" :
			: "r" (mk_vsid_data(p, ssize, flags)),
			  "r" (mk_esid_data(p, ssize, SLB_NUM_BOLTED + 1))
			: "memory");
	isync();

	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");

Annotation

Implementation Notes