The new sysfs code overwrites two fixed-length character arrays
that are each one byte shorter than they need to be, to hold
the trailing \0:
drivers/platform/x86/dell-smbios.c: In function 'build_tokens_sysfs':
drivers/platform/x86/dell-smbios.c:494:42: error: 'sprintf' writing a terminating nul past the end of the destination [-Werror=format-overflow=]
sprintf(buffer_location, "%04x_location",
drivers/platform/x86/dell-smbios.c:494:3: note: 'sprintf' output 14 bytes into a destination of size 13
drivers/platform/x86/dell-smbios.c:506:36: error: 'sprintf' writing a terminating nul past the end of the destination [-Werror=format-overflow=]
sprintf(buffer_value, "%04x_value",
drivers/platform/x86/dell-smbios.c:506:3: note: 'sprintf' output 11 bytes into a destination of size 10
This changes it to just use kasprintf(), which always gets it right.
Discovered with gcc-7.1.1 with the following commit reverted:
bd664f6b3e disable new gcc-7.1.1 warnings for now
Fixes: 33b9ca1e53 ("platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mario Limonciello <mario.limonciello@dell.com>
[dvhart: add subject prefix and reproducer details for context]
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
When a userspace interface is introduced to dell-smbios filtering
support will be used to make sure that userspace doesn't make calls
deemed unsafe or that can cause the kernel drivers to get out of
sync.
A blacklist is provided for the following:
- Items that are in use by other kernel drivers
- Items that are deemed unsafe (diagnostics, write-once, etc)
- Any items in the blacklist will be rejected.
Following that a whitelist is provided as follows:
- Each item has an associated capability. If a userspace interface
accesses this item, that capability will be tested to filter
the request.
- If the process provides CAP_SYS_RAWIO the whitelist will be
overridden.
When an item is not in the blacklist, or whitelist and the process
is run with insufficient capabilities the call will be rejected.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
This splits up the dell-smbios driver into two drivers:
* dell-smbios
* dell-smbios-smm
dell-smbios can operate with multiple different dispatcher drivers to
perform SMBIOS operations.
Also modify the interface that dell-laptop and dell-wmi use align to this
model more closely. Rather than a single global buffer being allocated
for all drivers, each driver will allocate and be responsible for it's own
buffer. The pointer will be passed to the calling function and each
dispatcher driver will then internally copy it to the proper location to
perform it's call.
Add defines for calls used by these methods in the dell-smbios.h header
for tracking purposes.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Currently userspace tools can access system tokens via the dcdbas
kernel module and a SMI call that will cause the platform to execute
SMM code.
With a goal in mind of deprecating the dcdbas kernel module a different
method for accessing these tokens from userspace needs to be created.
This is intentionally marked to only be readable as a process with
CAP_SYS_ADMIN as it can contain sensitive information about the
platform's configuration.
While adding this interface I found that some tokens are duplicated.
These need to be ignored from sysfs to avoid duplicate files.
MAINTAINERS was missing for this driver. Add myself and Pali to
maintainers list for it.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
The proper way to indicate that a system is a 'supported' Dell System
is by the presence of this string in OEM strings.
Allowing the driver to load on non-Dell systems will have undefined
results.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Later on these structures will be brought up to userspace.
the word "class" is a reserved word in c++ and this will prevent
uapi headers from being included directly in c++ programs.
To make life easier on these applications, prepare the change now.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
pr_fmt provides formatting to be used by the driver when
displaying errors and messages.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Pali Pohar <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
There are several cases where events handled in one of the dell-* drivers
need to be propagated to another dell-* driver.
This commit adds 3 generic functions:
dell_laptop_register_notifier()
dell_laptop_unregister_notifier()
dell_laptop_call_notifier()
It currently only defines 1 action:
DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED
Which is intended to propagate kbd_backlight_brightness_changed wmi
events from dell-wmi to dell-laptop (which contains the actual kbd
backlight driver).
These functions are put in dell-smbios as both dell-wmi and dell-laptop
use smbios functions and I do not want to put the notifier head in
either driver, as that will make the 2 drivers depend on each other.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
As dell_smi_error() is exported by dell-smbios, its prefix should be
consistent with other exported symbols, so change function name to
dell_smbios_error().
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
The dell_smi_error() method could be used by modules other than
dell-laptop for convenient translation of SMBIOS request errors into
errno values. Thus, move it to dell-smbios.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As dell-laptop has been changed to use dell_smbios_find_token() instead
of directly accessing members of the da_tokens table, the latter can be
marked static.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As dell-laptop has been changed to use dell_smbios_find_token() instead
of find_token_id() and find_token_location(), these functions can be
safely removed.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Ultimately, the da_tokens table should not be exported from dell-smbios.
Currently, in some cases, dell-laptop accesses that table's members
directly, so implement a new function, dell_smbios_find_token(), which
returns a pointer to an entry inside the da_tokens table with the given
token ID (or NULL if it is not found).
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As dell-laptop has been changed to always retrieve a pointer to the
SMBIOS buffer using dell_smbios_get_buffer(), the SMBIOS buffer can be
marked static.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Ultimately, the SMBIOS buffer should not be exported from dell-smbios.
Currently, dell-laptop accesses it directly using a global variable, so
make dell_smbios_get_buffer() return a pointer to the SMBIOS buffer and
replace all uses of the global variable with local variables.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
An SMBIOS buffer pointer does not need to be returned by
dell_smbios_send_request(), because SMBIOS call results are stored in
the buffer exported by the module.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Passing an SMBIOS buffer pointer to dell_smbios_send_request() is
redundant as it should always operate on the SMBIOS buffer exported from
the module.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As dell_send_request() is exported from the module, its prefix should be
consistent with other exported symbols, so change function name to
dell_smbios_send_request().
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As release_buffer() is exported from the module, it has to be renamed to
something less generic, so add a "dell_smbios_" prefix to the function
name.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As clear_buffer() is exported from the module, it has to be renamed to
something less generic, so add a "dell_smbios_" prefix to the function
name.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
As get_buffer() is exported from the module, it has to be renamed to
something less generic, so add a "dell_smbios_" prefix to the function
name.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Extract SMBIOS-related code from dell-laptop to a new kernel module,
dell-smbios. The static specifier is removed from exported symbols,
otherwise code is just moved around.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
[dvhart: Include linux/io.h in dell-smbios.c as caught by lkp]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
