Commit 2b1f6a04 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'adi-driver' 



Tom Hromatka says:

====================
sparc64: Add privileged ADI driver

ADI is a feature supported on SPARC M7 and newer processors to allow
hardware to catch rogue accesses to memory. ADI is supported for data
fetches only and not instruction fetches. An app can enable ADI on its
data pages, set version tags on them and use versioned addresses to
access the data pages. Upper bits of the address contain the version
tag. On M7 processors, upper four bits (bits 63-60) contain the version
tag. If a rogue app attempts to access ADI enabled data pages, its
access is blocked and processor generates an exception. Please see
Documentation/sparc/adi.txt for further details.

This patchset implements a char driver to read/write ADI versions from
privileged user space processes.  Intended consumers are makedumpfile
and crash.

v6:
  * Addressed a few action items from greg k-h
  * Added Reviewed-by Greg Kroah-Hartman and Shuah Khan
v5:
  * Fixed MODULE_LICENSE() for adi.c
v4:
  * Fixed messed up subject lines.
v3:
  * Really fixed the copyright headers to use SPDX GPL v2.  Really.
v2:
  * Simplified copyright headers
  * Completely reworked sparc64 selftests Makefiles.  Used the
    android selftests Makefiles as an example
  * Added run.sh and drivers_test.sh to the sparc64 selftest
    directory.  Used bpf/test_kmod.sh and the android selftests
    as examples
  * Minor cleanups in the selftest adi-test.c
  * Added calls to ksft_test_*() in the adi-test.c
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents fff75eb2 3c545084

drivers/char/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -540,5 +540,17 @@ source "drivers/s390/char/Kconfig" 


source "drivers/char/xillybus/Kconfig"



config ADI

	tristate "SPARC Privileged ADI driver"

	depends on SPARC64

	default m

	help

	  SPARC M7 and newer processors utilize ADI (Application Data

	  Integrity) to version and protect memory.  This driver provides

	  read/write access to the ADI versions for privileged processes.

	  This feature is also known as MCD (Memory Corruption Detection)

	  and SSM (Silicon Secured Memory).  Intended consumers of this

	  driver include crash and makedumpfile.



endmenu

drivers/char/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -57,3 +57,4 @@ js-rtc-y = rtc.o 


obj-$(CONFIG_XILLYBUS)		+= xillybus/

obj-$(CONFIG_POWERNV_OP_PANEL)	+= powernv-op-panel.o

obj-$(CONFIG_ADI)		+= adi.o

drivers/char/adi.c

0 → 100644
+239 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Privileged ADI driver for sparc64

 *

 * Author: Tom Hromatka <tom.hromatka@oracle.com>

 */

#include <linux/kernel.h>

#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/proc_fs.h>

#include <linux/slab.h>

#include <linux/uaccess.h>

#include <asm/asi.h>



#define MAX_BUF_SZ	PAGE_SIZE



static int adi_open(struct inode *inode, struct file *file)

{

	file->f_mode |= FMODE_UNSIGNED_OFFSET;

	return 0;

}



static int read_mcd_tag(unsigned long addr)

{

	long err;

	int ver;



	__asm__ __volatile__(

		"1:	ldxa [%[addr]] %[asi], %[ver]\n"

		"	mov 0, %[err]\n"

		"2:\n"

		"	.section .fixup,#alloc,#execinstr\n"

		"	.align 4\n"

		"3:	sethi %%hi(2b), %%g1\n"

		"	jmpl  %%g1 + %%lo(2b), %%g0\n"

		"	mov %[invalid], %[err]\n"

		"	.previous\n"

		"	.section __ex_table, \"a\"\n"

		"	.align 4\n"

		"	.word  1b, 3b\n"

		"	.previous\n"

		: [ver] "=r" (ver), [err] "=r" (err)

		: [addr] "r"  (addr), [invalid] "i" (EFAULT),

		  [asi] "i" (ASI_MCD_REAL)

		: "memory", "g1"

		);



	if (err)

		return -EFAULT;

	else

		return ver;

}



static ssize_t adi_read(struct file *file, char __user *buf,

			size_t count, loff_t *offp)

{

	size_t ver_buf_sz, bytes_read = 0;

	int ver_buf_idx = 0;

	loff_t offset;

	u8 *ver_buf;

	ssize_t ret;



	ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ);

	ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL);

	if (!ver_buf)

		return -ENOMEM;



	offset = (*offp) * adi_blksize();



	while (bytes_read < count) {

		ret = read_mcd_tag(offset);

		if (ret < 0)

			goto out;



		ver_buf[ver_buf_idx] = (u8)ret;

		ver_buf_idx++;

		offset += adi_blksize();



		if (ver_buf_idx >= ver_buf_sz) {

			if (copy_to_user(buf + bytes_read, ver_buf,

					 ver_buf_sz)) {

				ret = -EFAULT;

				goto out;

			}



			bytes_read += ver_buf_sz;

			ver_buf_idx = 0;



			ver_buf_sz = min(count - bytes_read,

					 (size_t)MAX_BUF_SZ);

		}

	}



	(*offp) += bytes_read;

	ret = bytes_read;

out:

	kfree(ver_buf);

	return ret;

}



static int set_mcd_tag(unsigned long addr, u8 ver)

{

	long err;



	__asm__ __volatile__(

		"1:	stxa %[ver], [%[addr]] %[asi]\n"

		"	mov 0, %[err]\n"

		"2:\n"

		"	.section .fixup,#alloc,#execinstr\n"

		"	.align 4\n"

		"3:	sethi %%hi(2b), %%g1\n"

		"	jmpl %%g1 + %%lo(2b), %%g0\n"

		"	mov %[invalid], %[err]\n"

		"	.previous\n"

		"	.section __ex_table, \"a\"\n"

		"	.align 4\n"

		"	.word 1b, 3b\n"

		"	.previous\n"

		: [err] "=r" (err)

		: [ver] "r" (ver), [addr] "r"  (addr),

		  [invalid] "i" (EFAULT), [asi] "i" (ASI_MCD_REAL)

		: "memory", "g1"

		);



	if (err)

		return -EFAULT;

	else

		return ver;

}



static ssize_t adi_write(struct file *file, const char __user *buf,

			 size_t count, loff_t *offp)

{

	size_t ver_buf_sz, bytes_written = 0;

	loff_t offset;

	u8 *ver_buf;

	ssize_t ret;

	int i;



	if (count <= 0)

		return -EINVAL;



	ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ);

	ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL);

	if (!ver_buf)

		return -ENOMEM;



	offset = (*offp) * adi_blksize();



	do {

		if (copy_from_user(ver_buf, &buf[bytes_written],

				   ver_buf_sz)) {

			ret = -EFAULT;

			goto out;

		}



		for (i = 0; i < ver_buf_sz; i++) {

			ret = set_mcd_tag(offset, ver_buf[i]);

			if (ret < 0)

				goto out;



			offset += adi_blksize();

		}



		bytes_written += ver_buf_sz;

		ver_buf_sz = min(count - bytes_written, (size_t)MAX_BUF_SZ);

	} while (bytes_written < count);



	(*offp) += bytes_written;

	ret = bytes_written;

out:

	__asm__ __volatile__("membar #Sync");

	kfree(ver_buf);

	return ret;

}



static loff_t adi_llseek(struct file *file, loff_t offset, int whence)

{

	loff_t ret = -EINVAL;



	switch (whence) {

	case SEEK_END:

	case SEEK_DATA:

	case SEEK_HOLE:

		/* unsupported */

		return -EINVAL;

	case SEEK_CUR:

		if (offset == 0)

			return file->f_pos;



		offset += file->f_pos;

		break;

	case SEEK_SET:

		break;

	}



	if (offset != file->f_pos) {

		file->f_pos = offset;

		file->f_version = 0;

		ret = offset;

	}



	return ret;

}



static const struct file_operations adi_fops = {

	.owner		= THIS_MODULE,

	.llseek		= adi_llseek,

	.open		= adi_open,

	.read		= adi_read,

	.write		= adi_write,

};



static struct miscdevice adi_miscdev = {

	.minor = MISC_DYNAMIC_MINOR,

	.name = KBUILD_MODNAME,

	.fops = &adi_fops,

};



static int __init adi_init(void)

{

	if (!adi_capable())

		return -EPERM;



	return misc_register(&adi_miscdev);

}



static void __exit adi_exit(void)

{

	misc_deregister(&adi_miscdev);

}



module_init(adi_init);

module_exit(adi_exit);



MODULE_AUTHOR("Tom Hromatka <tom.hromatka@oracle.com>");

MODULE_DESCRIPTION("Privileged interface to ADI");

MODULE_VERSION("1.0");

MODULE_LICENSE("GPL v2");

tools/testing/selftests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ TARGETS += ptrace 
TARGETS += seccomp

TARGETS += sigaltstack

TARGETS += size

TARGETS += sparc64

TARGETS += splice

TARGETS += static_keys

TARGETS += sync

tools/testing/selftests/sparc64/Makefile

0 → 100644
+46 −0
Original line number Diff line number Diff line 
SUBDIRS := drivers



TEST_PROGS := run.sh



.PHONY: all clean



include ../lib.mk



all:

	@for DIR in $(SUBDIRS); do		\

		BUILD_TARGET=$(OUTPUT)/$$DIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		make OUTPUT=$$BUILD_TARGET -C $$DIR $@;\

		#SUBDIR test prog name should be in the form: SUBDIR_test.sh \

		TEST=$$DIR"_test.sh"; \

		if [ -e $$DIR/$$TEST ]; then \

			rsync -a $$DIR/$$TEST $$BUILD_TARGET/; \

		fi \

	done



override define RUN_TESTS

	@cd $(OUTPUT); ./run.sh

endef



override define INSTALL_RULE

	mkdir -p $(INSTALL_PATH)

	install -t $(INSTALL_PATH) $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES)



	@for SUBDIR in $(SUBDIRS); do \

		BUILD_TARGET=$(OUTPUT)/$$SUBDIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$SUBDIR INSTALL_PATH=$(INSTALL_PATH)/$$SUBDIR install; \

	done;

endef



override define EMIT_TESTS

	echo "./run.sh"

endef



override define CLEAN

	@for DIR in $(SUBDIRS); do		\

		BUILD_TARGET=$(OUTPUT)/$$DIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		make OUTPUT=$$BUILD_TARGET -C $$DIR $@;\

	done

endef

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