kernel/include/sound/control.h, branch linux-5.11.y

ALSA: make snd_kcontrol_new name a normal string

2020-10-26T19:28:59Z

When building with W=2, there are lots of warnings about the snd_kcontrol_new name field being an array of 'unsigned char' but initialized to a string: include/sound/soc.h:93:48: warning: pointer targets in initialization of 'const unsigned char *' from 'char *' differ in signedness [-Wpointer-sign] Make it a regular 'char *' to avoid flooding the build log with this. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20201026165715.3723704-1-arnd@kernel.org Signed-off-by: Takashi Iwai

ALSA: Replace the word "slave" in vmaster API

2020-07-20T08:10:47Z

Follow the recent inclusive terminology guidelines and replace the word "slave" in vmaster API. I chose the word "follower" at this time since it seems fitting for the purpose. Note that the word "master" is kept in API, since it refers rather to audio master volume control. Also, while we're at it, a typo in comments is corrected, too. Link: https://lore.kernel.org/r/20200717154517.27599-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: Replace zero-length array with flexible-array

2020-05-07T20:30:36Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200507192223.GA16335@embeddedor Signed-off-by: Takashi Iwai

ALSA: control: Add verification for kctl accesses

2020-01-04T08:37:59Z

The current implementation of ALSA control API fully relies on the callbacks of each driver, and there is no verification of the values passed via API. This patch is an attempt to improve the situation slightly by adding the validation code for the values stored via info and get callbacks. The patch adds a new kconfig, CONFIG_SND_CTL_VALIDATION. It depends on CONFIG_SND_DEBUG and off as default since the validation would require a slight overhead including the additional call of info callback at each get callback invocation. When this config is enabled, the values stored by each info callback invocation are verified, namely: - Whether the info type is valid - Whether the number of enum items is non-zero - Whether the given info count is within the allowed boundary Similarly, the values stored at each get callback are verified as well: - Whether the values are within the given range - Whether the values are aligned with the given step - Whether any further changes are seen in the data array over the given info count The last point helps identifying a possibly invalid data type access, typically a case where the info callback declares the type being SNDRV_CTL_ELEM_TYPE_ENUMERATED while the get/put callbacks store the values in value.integer.value[] array. When a validation fails, the ALSA core logs an error message including the device and the control ID, and the API call also returns an error. So, with the new validation turned on, the driver behavior difference may be visible on user-space, too -- it's intentional, though, so that we can catch an error more clearly. The patch also introduces a new ctl access type, SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK. A driver may pass this flag with other access bits to indicate that the ctl element won't be verified. It's useful when a driver code is specially written to access the data greater than info->count size by some reason. For example, this flag is actually set now in HD-audio HDMI codec driver which needs to clear the data array in the case of the disconnected monitor. Also, the PCM channel-map helper code is slightly modified to avoid the false-positive hit by this validation code, too. Link: https://lore.kernel.org/r/20200104083556.27789-1-tiwai@suse.de Signed-off-by: Takashi Iwai

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

ALSA: control: Hardening for potential Spectre v1

2018-04-25T08:37:46Z

As recently Smatch suggested, a few places in ALSA control core codes may expand the array directly from the user-space value with speculation: sound/core/control.c:1003 snd_ctl_elem_lock() warn: potential spectre issue 'kctl->vd' sound/core/control.c:1031 snd_ctl_elem_unlock() warn: potential spectre issue 'kctl->vd' sound/core/control.c:844 snd_ctl_elem_info() warn: potential spectre issue 'kctl->vd' sound/core/control.c:891 snd_ctl_elem_read() warn: potential spectre issue 'kctl->vd' sound/core/control.c:939 snd_ctl_elem_write() warn: potential spectre issue 'kctl->vd' Although all these seem doing only the first load without further reference, we may want to stay in a safer side, so hardening with array_index_nospec() would still make sense. In this patch, we put array_index_nospec() to the common snd_ctl_get_ioff*() helpers instead of each caller. These helpers are also referred from some drivers, too, and basically all usages are to calculate the array index from the user-space value, hence it's better to cover there. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter Cc: Signed-off-by: Takashi Iwai

ALSA: hda - Fix yet remaining issue with vmaster 0dB initialization

2017-11-22T11:34:56Z

The previous fix for addressing the breakage in vmaster slave initialization, commit a91d66129fb9 ("ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal"), introduced a new helper to process over each slave kctl. However, this helper passes only the original kctl, not the virtual slave kctl. As a result, HD-audio driver (which is the only user so far) couldn't initialize the slave correctly because it's trying to update the value directly with the original kctl, not with the mapped kctl. This patch fixes the situation again by passing both the mapped slaved and original slave kctls to the function. Luckily there is a single caller as of now, so changing the call signature is no big matter. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=197959 Fixes: a91d66129fb9 ("ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal") Cc: Signed-off-by: Takashi Iwai

ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal

2017-10-18T10:27:00Z

The commit 99b5c5bb9a54 ("ALSA: hda - Remove the use of set_fs()") converted the get_kctl_0dB_offset() call for killing set_fs() usage in HD-audio codec code. The conversion assumed that the TLV callback used in HD-audio code is only snd_hda_mixer_amp() and applies the TLV calculation locally. Although this assumption is correct, and all slave kctls are actually with that callback, the current code is still utterly buggy; it doesn't hit this condition and falls back to the next check. It's because the function gets called after adding slave kctls to vmaster. By assigning a slave kctl, the slave kctl object is faked inside vmaster code, and the whole kctl ops are overridden. Thus the callback op points to a different value from what we've assumed. More badly, as reported by the KERNEXEC and UDEREF features of PaX, the code flow turns into the unexpected pitfall. The next fallback check is SNDRV_CTL_ELEM_ACCESS_TLV_READ access bit, and this always hits for each kctl with TLV. Then it evaluates the callback function pointer wrongly as if it were a TLV array. Although currently its side-effect is fairly limited, this incorrect reference may lead to an unpleasant result. For addressing the regression, this patch introduces a new helper to vmaster code, snd_ctl_apply_vmaster_slaves(). This works similarly like the existing map_slaves() in hda_codec.c: it loops over the slave list of the given master, and applies the given function to each slave. Then the initializer function receives the right kctl object and we can compare the correct pointer instead of the faked one. Also, for catching the similar breakage in future, give an error message when the unexpected TLV callback is found and bail out immediately. Fixes: 99b5c5bb9a54 ("ALSA: hda - Remove the use of set_fs()") Reported-by: PaX Team Cc: # v4.13 Signed-off-by: Takashi Iwai

sched/headers: Prepare to remove spurious inclusion dependencies

2017-03-02T07:42:41Z

In the following patches we are going to remove various headers from sched.h and other headers that sched.h includes. To make those patches build cleanly prepare the scene by adding dependencies to various files that learned to rely on those to-be-removed dependencies. These changes all make sense standalone: they add a header for a data type that a particular .c or .h file is using. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

ALSA: hda - Update to use the new jack kctls method

2015-04-27T19:37:42Z

Jack snd_kcontrols can now be created during snd_jack_new() or by later calling snd_jack_add_new_kctls(). This patch creates the jacks during the initialisation stage for both phantom and non phantom jacks. Signed-off-by: Jie Yang Signed-off-by: Takashi Iwai