From ddc5c9a37be4517270453ce909d3dfcc8de58230 Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Sat, 3 Dec 2016 17:29:28 +0800 Subject: misc: set error code when devm_kstrdup fails In function sram_reserve_regions(), the value of return variable ret should be negative on failures. However, the value of ret may be 0 even if the call to devm_kstrdup() returns a NULL pointer. This patch explicitly assigns "-ENOMEM" to ret on the path that devm_kstrdup() fails. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188651 Signed-off-by: Pan Bian Signed-off-by: Greg Kroah-Hartman --- drivers/misc/sram.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/misc/sram.c') diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index b33ab8ce47ab..07ec2a8a9343 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -249,8 +249,10 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) block->label = devm_kstrdup(sram->dev, label, GFP_KERNEL); - if (!block->label) + if (!block->label) { + ret = -ENOMEM; goto err_chunks; + } dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", block->export ? "exported " : "", block->label, -- cgit From cdd1737cba7a6453c9453c55c4537a15cc1f49b2 Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Thu, 12 Jan 2017 14:52:18 -0600 Subject: misc: sram: Split sram data structures into local header In preparation of a coming file split of the sram driver, move the common data structures into a local header file that can be shared between files related to the sram driver. Signed-off-by: Dave Gerlach Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman --- drivers/misc/sram.c | 30 ++---------------------------- drivers/misc/sram.h | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+), 28 deletions(-) create mode 100644 drivers/misc/sram.h (limited to 'drivers/misc/sram.c') diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index 07ec2a8a9343..5a6e001845c2 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -31,35 +31,9 @@ #include #include -#define SRAM_GRANULARITY 32 - -struct sram_partition { - void __iomem *base; - - struct gen_pool *pool; - struct bin_attribute battr; - struct mutex lock; -}; - -struct sram_dev { - struct device *dev; - void __iomem *virt_base; - - struct gen_pool *pool; - struct clk *clk; +#include "sram.h" - struct sram_partition *partition; - u32 partitions; -}; - -struct sram_reserve { - struct list_head list; - u32 start; - u32 size; - bool export; - bool pool; - const char *label; -}; +#define SRAM_GRANULARITY 32 static ssize_t sram_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, diff --git a/drivers/misc/sram.h b/drivers/misc/sram.h new file mode 100644 index 000000000000..52501a84468c --- /dev/null +++ b/drivers/misc/sram.h @@ -0,0 +1,39 @@ +/* + * Defines for the SRAM driver + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef __SRAM_H +#define __SRAM_H + +struct sram_partition { + void __iomem *base; + + struct gen_pool *pool; + struct bin_attribute battr; + struct mutex lock; + struct list_head list; +}; + +struct sram_dev { + struct device *dev; + void __iomem *virt_base; + + struct gen_pool *pool; + struct clk *clk; + + struct sram_partition *partition; + u32 partitions; +}; + +struct sram_reserve { + struct list_head list; + u32 start; + u32 size; + bool export; + bool pool; + const char *label; +}; +#endif /* __SRAM_H */ -- cgit From 37afff0d87c9939843c664970af6c6d952f95712 Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Thu, 12 Jan 2017 14:52:20 -0600 Subject: misc: sram: Integrate protect-exec reserved sram area type Introduce a new "protect-exec" reserved sram area type which is makes use of the the existing functionality provided for the "pool" sram region type for use with the genalloc framework and with the added requirement that it be maintained as read-only and executable while allowing for an arbitrary number of drivers to share the space. This introduces a common way to maintain a region of sram as read-only and executable and also introduces a helper function, sram_exec_copy, which allows for copying data to this protected region while maintaining locking to avoid conflicts between multiple users of the same space. A region of memory that is marked with the "protect-exec" flag in the device tree also has the requirement of providing a page aligned block of memory so that the page attribute manipulation does not affect surrounding regions. Also, selectively enable this only for builds that support set_memory_* calls, for now just ARM, through the use of Kconfig. Signed-off-by: Dave Gerlach Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/sram/sram.txt | 6 ++++++ drivers/misc/Kconfig | 4 ++++ drivers/misc/Makefile | 1 + drivers/misc/sram.c | 21 +++++++++++++++++++-- drivers/misc/sram.h | 1 + 5 files changed, 31 insertions(+), 2 deletions(-) (limited to 'drivers/misc/sram.c') diff --git a/Documentation/devicetree/bindings/sram/sram.txt b/Documentation/devicetree/bindings/sram/sram.txt index 068c2c03c38f..267da4410aef 100644 --- a/Documentation/devicetree/bindings/sram/sram.txt +++ b/Documentation/devicetree/bindings/sram/sram.txt @@ -42,6 +42,12 @@ Optional properties in the area nodes: and in use by another device or devices - export : indicates that the reserved SRAM area may be accessed outside of the kernel, e.g. by bootloader or userspace +- protect-exec : Same as 'pool' above but with the additional + constraint that code wil be run from the region and + that the memory is maintained as read-only, executable + during code execution. NOTE: This region must be page + aligned on start and end in order to properly allow + manipulation of the page attributes. - label : the name for the reserved partition, if omitted, the label is taken from the node name excluding the unit address. diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 64971baf11fa..0444a8f9b094 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -474,11 +474,15 @@ config SRAM bool "Generic on-chip SRAM driver" depends on HAS_IOMEM select GENERIC_ALLOCATOR + select SRAM_EXEC if ARM help This driver allows you to declare a memory region to be managed by the genalloc API. It is supposed to be used for small on-chip SRAM areas found on many SoCs. +config SRAM_EXEC + bool + config VEXPRESS_SYSCFG bool "Versatile Express System Configuration driver" depends on VEXPRESS_CONFIG diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 31983366090a..7a3ea89339b4 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_INTEL_MEI) += mei/ obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/ obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o obj-$(CONFIG_SRAM) += sram.o +obj-$(CONFIG_SRAM_EXEC) += sram-exec.o obj-y += mic/ obj-$(CONFIG_GENWQE) += genwqe/ obj-$(CONFIG_ECHO) += echo/ diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index 5a6e001845c2..d1185b78cf9a 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -122,6 +122,18 @@ static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block, if (ret) return ret; } + if (block->protect_exec) { + ret = sram_check_protect_exec(sram, block, part); + if (ret) + return ret; + + ret = sram_add_pool(sram, block, start, part); + if (ret) + return ret; + + sram_add_protect_exec(part); + } + sram->partitions++; return 0; @@ -207,7 +219,11 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) if (of_find_property(child, "pool", NULL)) block->pool = true; - if ((block->export || block->pool) && block->size) { + if (of_find_property(child, "protect-exec", NULL)) + block->protect_exec = true; + + if ((block->export || block->pool || block->protect_exec) && + block->size) { exports++; label = NULL; @@ -269,7 +285,8 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) goto err_chunks; } - if ((block->export || block->pool) && block->size) { + if ((block->export || block->pool || block->protect_exec) && + block->size) { ret = sram_add_partition(sram, block, res->start + block->start); if (ret) { diff --git a/drivers/misc/sram.h b/drivers/misc/sram.h index b268cd3f55bb..c181ce4c8fca 100644 --- a/drivers/misc/sram.h +++ b/drivers/misc/sram.h @@ -34,6 +34,7 @@ struct sram_reserve { u32 size; bool export; bool pool; + bool protect_exec; const char *label; }; -- cgit