- 05 Dec, 2019 40 commits
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Andrey Konovalov authored
Add kcov_remote_start()/kcov_remote_stop() annotations to the vhost_worker() function, which is responsible for processing vhost works. Since vhost_worker() threads are spawned per vhost device instance the common kcov handle is used for kcov_remote_start()/stop() annotations (see Documentation/dev-tools/kcov.rst for details). As the result kcov can now be used to collect coverage from vhost worker threads. Link: http://lkml.kernel.org/r/e49d5d154e5da6c9ada521d2b7ce10a49ce9f98b.1572366574.git.andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Windsor <dwindsor@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Marco Elver <elver@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Konovalov authored
Add kcov_remote_start()/kcov_remote_stop() annotations to the hub_event() function, which is responsible for processing events on USB buses, in particular events that happen during USB device enumeration. Since hub_event() is run in a global background kernel thread (see Documentation/dev-tools/kcov.rst for details), each USB bus gets a unique global handle from the USB subsystem kcov handle range. As the result kcov can now be used to collect coverage from events that happen on a particular USB bus. [akpm@linux-foundation.org: avoid patch conflicts to make life easier for Andrew] Link: http://lkml.kernel.org/r/de4fe1c219db2d002d905dc1736e2a3bfa1db997.1572366574.git.andreyknvl@google.comSigned-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Windsor <dwindsor@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Marco Elver <elver@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Andrey Konovalov authored
Patch series " kcov: collect coverage from usb and vhost", v3. This patchset extends kcov to allow collecting coverage from backgound kernel threads. This extension requires custom annotations for each of the places where coverage collection is desired. This patchset implements this for hub events in the USB subsystem and for vhost workers. See the first patch description for details about the kcov extension. The other two patches apply this kcov extension to USB and vhost. Examples of other subsystems that might potentially benefit from this when custom annotations are added (the list is based on process_one_work() callers for bugs recently reported by syzbot): 1. fs: writeback wb_workfn() worker, 2. net: addrconf_dad_work()/addrconf_verify_work() workers, 3. net: neigh_periodic_work() worker, 4. net/p9: p9_write_work()/p9_read_work() workers, 5. block: blk_mq_run_work_fn() worker. These patches have been used to enable coverage-guided USB fuzzing with syzkaller for the last few years, see the details here: https://github.com/google/syzkaller/blob/master/docs/linux/external_fuzzing_usb.md This patchset has been pushed to the public Linux kernel Gerrit instance: https://linux-review.googlesource.com/c/linux/kernel/git/torvalds/linux/+/1524 This patch (of 3): Add background thread coverage collection ability to kcov. With KCOV_ENABLE coverage is collected only for syscalls that are issued from the current process. With KCOV_REMOTE_ENABLE it's possible to collect coverage for arbitrary parts of the kernel code, provided that those parts are annotated with kcov_remote_start()/kcov_remote_stop(). This allows to collect coverage from two types of kernel background threads: the global ones, that are spawned during kernel boot in a limited number of instances (e.g. one USB hub_event() worker thread is spawned per USB HCD); and the local ones, that are spawned when a user interacts with some kernel interface (e.g. vhost workers). To enable collecting coverage from a global background thread, a unique global handle must be assigned and passed to the corresponding kcov_remote_start() call. Then a userspace process can pass a list of such handles to the KCOV_REMOTE_ENABLE ioctl in the handles array field of the kcov_remote_arg struct. This will attach the used kcov device to the code sections, that are referenced by those handles. Since there might be many local background threads spawned from different userspace processes, we can't use a single global handle per annotation. Instead, the userspace process passes a non-zero handle through the common_handle field of the kcov_remote_arg struct. This common handle gets saved to the kcov_handle field in the current task_struct and needs to be passed to the newly spawned threads via custom annotations. Those threads should in turn be annotated with kcov_remote_start()/kcov_remote_stop(). Internally kcov stores handles as u64 integers. The top byte of a handle is used to denote the id of a subsystem that this handle belongs to, and the lower 4 bytes are used to denote the id of a thread instance within that subsystem. A reserved value 0 is used as a subsystem id for common handles as they don't belong to a particular subsystem. The bytes 4-7 are currently reserved and must be zero. In the future the number of bytes used for the subsystem or handle ids might be increased. When a particular userspace process collects coverage by via a common handle, kcov will collect coverage for each code section that is annotated to use the common handle obtained as kcov_handle from the current task_struct. However non common handles allow to collect coverage selectively from different subsystems. Link: http://lkml.kernel.org/r/e90e315426a384207edbec1d6aa89e43008e4caf.1572366574.git.andreyknvl@google.comSigned-off-by:
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Kees Cook authored
As we've done with VFS, string operations, etc, reject usercopy sizes larger than INT_MAX, which would be nice to have for catching bugs related to size calculation overflows[1]. This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data section: text data bss dec hex filename 19691167 5134320 1646664 26472151 193eed7 vmlinux.before 19691177 5136300 1646664 26474141 193f69d vmlinux.after [1] https://marc.info/?l=linux-s390&m=156631939010493&w=2 Link: http://lkml.kernel.org/r/201908251612.F9902D7A@keescookSigned-off-by:Kees Cook <keescook@chromium.org> Suggested-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Daniel Vetter authored
The hardened usercpy code is too paranoid ever since commit 6a30afa8c1fb ("uaccess: disallow > INT_MAX copy sizes") Code itself should have been fine as-is. Link: http://lkml.kernel.org/r/20191106164755.31478-1-daniel.vetter@ffwll.chSigned-off-by:Daniel Vetter <daniel.vetter@intel.com> Reported-by: syzbot+fb77e97ebf0612ee6914@syzkaller.appspotmail.com Fixes: 6a30afa8c1fb ("uaccess: disallow > INT_MAX copy sizes") Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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Ben Dooks (Codethink) authored
Include <linux/rio_drv.h> for the missing declarations of functions exported from this file. Fixes the following sparse warnings: drivers/rapidio/rio-access.c:59:1: warning: symbol '__rio_local_read_config_8' was not declared. Should it be static? drivers/rapidio/rio-access.c:60:1: warning: symbol '__rio_local_read_config_16' was not declared. Should it be static? drivers/rapidio/rio-access.c:61:1: warning: symbol '__rio_local_read_config_32' was not declared. Should it be static? drivers/rapidio/rio-access.c:62:1: warning: symbol '__rio_local_write_config_8' was not declared. Should it be static? drivers/rapidio/rio-access.c:63:1: warning: symbol '__rio_local_write_config_16' was not declared. Should it be static? drivers/rapidio/rio-access.c:64:1: warning: symbol '__rio_local_write_config_32' was not declared. Should it be static? drivers/rapidio/rio-access.c:112:1: warning: symbol 'rio_mport_read_config_8' was not declared. Should it be static? drivers/rapidio/rio-access.c:113:1: warning: symbol 'rio_mport_read_config_16' was not declared. Should it be static? drivers/rapidio/rio-access.c:114:1: warning: symbol 'rio_mport_read_config_32' was not declared. Should it be static? drivers/rapidio/rio-access.c:115:1: warning: symbol 'rio_mport_write_config_8' was not declared. Should it be static? drivers/rapidio/rio-access.c:116:1: warning: symbol 'rio_mport_write_config_16' was not declared. Should it be static? drivers/rapidio/rio-access.c:117:1: warning: symbol 'rio_mport_write_config_32' was not declared. Should it be static? drivers/rapidio/rio-access.c:136:5: warning: symbol 'rio_mport_send_doorbell' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20191017115103.684-1-ben.dooks@codethink.co.ukSigned-off-by:
Ben Dooks <ben.dooks@codethink.co.uk> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alex.bou9@gmail.com> Signed-off-by:
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Ben Dooks (Codethink) authored
Include <linux/rio_drv.h> for the missing declarations of functions exported from this file. Fixes the following sparse warnings: drivers/rapidio/rio-driver.c:53:16: warning: symbol 'rio_dev_get' was not declared. Should it be static? drivers/rapidio/rio-driver.c:70:6: warning: symbol 'rio_dev_put' was not declared. Should it be static? drivers/rapidio/rio-driver.c:150:5: warning: symbol 'rio_register_driver' was not declared. Should it be static? drivers/rapidio/rio-driver.c:169:6: warning: symbol 'rio_unregister_driver' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20191017114923.10888-1-ben.dooks@codethink.co.ukSigned-off-by:
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Krzysztof Kozlowski authored
Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.orgSigned-off-by:
Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by:
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Alexey Dobriyan authored
ELF reads done by the kernel have very complicated error detection code which better live in one place. Link: http://lkml.kernel.org/r/20191005165215.GB26927@avx2Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
Link: http://lkml.kernel.org/r/20191005165049.GA26927@avx2Signed-off-by:
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Heiher authored
This adds the promised selftest for epoll. It will verify the wakeups of epoll. Including leaf and nested mode, epoll_wait() and poll() and multi-threads. Link: http://lkml.kernel.org/r/20191009121518.4027-1-r@hev.ccSigned-off-by:
hev <r@hev.cc> Reviewed-by:
Roman Penyaev <rpenyaev@suse.de> Cc: Jason Baron <jbaron@akamai.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
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Heiher authored
Take the case where we have: t0 | (ew) e0 | (et) e1 | (lt) s0 t0: thread 0 e0: epoll fd 0 e1: epoll fd 1 s0: socket fd 0 ew: epoll_wait et: edge-trigger lt: level-trigger We remove unnecessary wakeups to prevent the nested epoll that working in edge- triggered mode to waking up continuously. Test code: #include <unistd.h> #include <sys/epoll.h> #include <sys/socket.h> int main(int argc, char *argv[]) { int sfd[2]; int efd[2]; struct epoll_event e; if (socketpair(AF_UNIX, SOCK_STREAM, 0, sfd) < 0) goto out; efd[0] = epoll_create(1); if (efd[0] < 0) goto out; efd[1] = epoll_create(1); if (efd[1] < 0) goto out; e.events = EPOLLIN; if (epoll_ctl(efd[1], EPOLL_CTL_ADD, sfd[0], &e) < 0) goto out; e.events = EPOLLIN | EPOLLET; if (epoll_ctl(efd[0], EPOLL_CTL_ADD, efd[1], &e) < 0) goto out; if (write(sfd[1], "w", 1) != 1) goto out; if (epoll_wait(efd[0], &e, 1, 0) != 1) goto out; if (epoll_wait(efd[0], &e, 1, 0) != 0) goto out; close(efd[0]); close(efd[1]); close(sfd[0]); close(sfd[1]); return 0; out: return -1; } More tests: https://github.com/heiher/epoll-wakeup Link: http://lkml.kernel.org/r/20191009060516.3577-1-r@hev.ccSigned-off-by: -
Jason Baron authored
Currently, ep_poll_safewake() in the CONFIG_DEBUG_LOCK_ALLOC case uses ep_call_nested() in order to pass the correct subclass argument to spin_lock_irqsave_nested(). However, ep_call_nested() adds unnecessary checks for epoll depth and loops that are already verified when doing EPOLL_CTL_ADD. This mirrors a conversion that was done for !CONFIG_DEBUG_LOCK_ALLOC in: commit 37b5e521 ("epoll: remove ep_call_nested() from ep_eventpoll_poll()") Link: http://lkml.kernel.org/r/1567628549-11501-1-git-send-email-jbaron@akamai.comSigned-off-by:
Jason Baron <jbaron@akamai.com> Reviewed-by:
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Joe Perches authored
The is_maintained_obsolete function can be called twice using the same filename. This function spawns a process using get_maintainer.pl. Store the status of each filename when spawned and use the stored result to eliminate the spawning of unnecessary duplicate child processes. Example: old: $ time ./scripts/checkpatch.pl hp100-Move-to-staging.patch > /dev/null real 0m1.767s user 0m1.634s sys 0m0.141s new: $ time ./scripts/checkpatch.pl hp100-Move-to-staging.patch > /dev/null real 0m1.184s user 0m1.085s sys 0m0.103s Link: http://lkml.kernel.org/r/b982566a2b9b4825badce36fdfc3032bd0005151.camel@perches.comSigned-off-by:
Joe Perches <joe@perches.com> Signed-off-by:
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Joe Perches authored
Ignore all upper-case variants before and after SI units like mA, mV and uV so uses like RANGE_mA do not emit a CAMELCASE message. Link: http://lkml.kernel.org/r/5ce6f9131327fd2e12d7a0e20a55f588448de090.camel@perches.comSigned-off-by:
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Huang Shijie authored
Follow the kernel conventions, rename addr_in_gen_pool to gen_pool_has_addr. [sjhuang@iluvatar.ai: fix Documentation/ too] Link: http://lkml.kernel.org/r/20181229015914.5573-1-sjhuang@iluvatar.ai Link: http://lkml.kernel.org/r/20181228083950.20398-1-sjhuang@iluvatar.aiSigned-off-by:
Huang Shijie <sjhuang@iluvatar.ai> Reviewed-by:
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Huang Shijie authored
We use addr_in_gen_pool() in a driver module. So export it. Link: http://lkml.kernel.org/r/20181224070622.22197-2-sjhuang@iluvatar.aiSigned-off-by:
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Trent Piepho authored
In some cases the previous algorithm would not return the closest approximation. This would happen when a semi-convergent was the closest, as the previous algorithm would only consider convergents. As an example, consider an initial value of 5/4, and trying to find the closest approximation with a maximum of 4 for numerator and denominator. The previous algorithm would return 1/1 as the closest approximation, while this version will return the correct answer of 4/3. To do this, the main loop performs effectively the same operations as it did before. It must now keep track of the last three approximations, n2/d2 .. n0/d0, while before it only needed the last two. If an exact answer is not found, the algorithm will now calculate the best semi-convergent term, t, which is a single expression with two divisions: min((max_numerator - n0) / n1, (max_denominator - d0) / d1) This will be used if it is better than previous convergent. The test for this is generally a simple comparison, 2*t > a. But in an edge case, where the convergent's final term is even and the best allowable semi-convergent has a final term of exactly half the convergent's final term, the more complex comparison (d0*dp > d1*d) is used. I also wrote some comments explaining the code. While one still needs to look up the math elsewhere, they should help a lot to follow how the code relates to that math. This routine is used in two places in the video4linux code, but in those cases it is only used to reduce a fraction to lowest terms, which the existing code will do correctly. This could be done more efficiently with a different library routine but it would still be the Euclidean alogrithm at its heart. So no change. The remain users are places where a fractional PLL divider is programmed. What would happen is something asked for a clock of X MHz but instead gets Y MHz, where Y is close to X but not exactly due to the hardware limitations. After this change they might, in some cases, get Y' MHz, where Y' is a little closer to X then Y was. Users like this are: Three UARTs, in 8250_mid, 8250_lpss, and imx. One GPU in vp4_hdmi. And three clock drivers, clk-cdce706, clk-si5351, and clk-fractional-divider. The last is a generic clock driver and so would have more users referenced via device tree entries. I think there's a bug in that one, it's limiting an N bit field that is offset-by-1 to the range 0 .. (1<<N)-2, when it should be (1<<N)-1 as the upper limit. I have an IMX system, one of the UARTs using this, so I can provide a real example. If I request a custom baud rate of 1499978, the driver will program the PLL to produce a baud rate of 1500000. After this change, the fractional divider in the UART is programmed to a ratio of 65535/65536, which produces a baud rate of 1499977.0625. Closer to the requested value. Link: http://lkml.kernel.org/r/20190330205855.19396-1-tpiepho@gmail.comSigned-off-by:Trent Piepho <tpiepho@gmail.com> Cc: Oskar Schirmer <oskar@scara.com> Signed-off-by:
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Laura Abbott authored
kmem_cache_alloc_bulk/kmem_cache_free_bulk are used to make multiple allocations of the same size to avoid the overhead of multiple kmalloc/kfree calls. Extend the kmem_cache tests to make some calls to these APIs. Link: http://lkml.kernel.org/r/20191107191447.23058-1-labbott@redhat.comSigned-off-by:
Laura Abbott <labbott@redhat.com> Reviewed-by:
Alexander Potapenko <glider@google.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sandeep Patil <sspatil@android.com> Cc: Jann Horn <jannh@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by:
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Wei Yang authored
After move parent assignment out, we can check the color directly. Link: http://lkml.kernel.org/r/20191028021442.5450-2-richardw.yang@linux.intel.comSigned-off-by:
Wei Yang <richardw.yang@linux.intel.com> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by:
Michel Lespinasse <walken@google.com> Reviewed-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Wei Yang authored
Both in Case 2 and 3, we exchange n and s. This mean no matter whether child2 is NULL or not, successor's parent should be assigned to node's. This patch takes this step out to make it explicit and reduce the ambiguity. Besides, this step reduces some symbol size like rb_erase(). KERN_CONFIG upstream patched OPT_FOR_PERF 877 870 OPT_FOR_SIZE 635 621 Link: http://lkml.kernel.org/r/20191028021442.5450-1-richardw.yang@linux.intel.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in set_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/3543ffc3668ad4ed4c00e8ebaf14a5559fd6ddf2.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
William Breathitt Gray <vilhelm.gray@gmail.com> Tested-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Phil Reid <preid@electromag.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Mathias Duckeck <m.duckeck@kunbus.de> Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk> Signed-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/c2b1ed62caf6fce6e5681809a50c05ce6acdf2a6.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/8a39ee772247d4b7d752b32dbacc06c1cdcb60b5.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Utilize for_each_set_clump8 macro, and the bitmap_set_value8 and bitmap_get_value8 functions, where appropriate. In addition, remove the now unnecessary temp_mask and temp_shift members of the intel_soc_dts_sensor_entry structure. Link: http://lkml.kernel.org/r/2d3c74e9a00a52954f31d19e04623a7f4bc85520.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in set_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/7ea2df7182a50a1136ca36edc46dffcb2446fd27.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in set_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. An improvement in this case is that banks that are not masked will now be skipped. Link: http://lkml.kernel.org/r/5b24887e97f3093e4832d7c50a1093f537e91ab4.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/d5d22fa9809dcf8330f4381dbe7e7ca37990e79f.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
Linus Walleij <linus.walleij@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Lukas Wunner <lukas@wunner.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Mathias Duckeck <m.duckeck@kunbus.de> Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk> Cc: Phil Reid <preid@electromag.com.au> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk> Signed-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/b30f131b4634caf5a70f12e01496f71631a17305.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/7a0d2c964e7f2d289b16c63ff6b06fc1f4c50d4d.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/0de53d7021b2d6db10294473cd8a1b6102bcec94.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/b0631b6d489f85008480399df283ccd33ecfe310.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
Replace verbose implementation in get_multiple/set_multiple callbacks with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/08b9c9a3e75ef1ab0d172223d10a1661f2b43fe2.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
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William Breathitt Gray authored
The introduction of the for_each_set_clump8 macro warrants test cases to verify the implementation. This patch adds test case checks for whether an out-of-bounds clump index is returned, a zero clump is returned, or the returned clump value differs from the expected clump value. Link: http://lkml.kernel.org/r/febc0fb8151e3e3fdd61c34da9193d1c4d7e6c12.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by:
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William Breathitt Gray authored
Pach series "Introduce the for_each_set_clump8 macro", v18. While adding GPIO get_multiple/set_multiple callback support for various drivers, I noticed a pattern of looping manifesting that would be useful standardized as a macro. This patchset introduces the for_each_set_clump8 macro and utilizes it in several GPIO drivers. The for_each_set_clump macro8 facilitates a for-loop syntax that iterates over a memory region entire groups of set bits at a time. For example, suppose you would like to iterate over a 32-bit integer 8 bits at a time, skipping over 8-bit groups with no set bit, where XXXXXXXX represents the current 8-bit group: Example: 10111110 00000000 11111111 00110011 First loop: 10111110 00000000 11111111 XXXXXXXX Second loop: 10111110 00000000 XXXXXXXX 00110011 Third loop: XXXXXXXX 00000000 11111111 00110011 Each iteration of the loop returns the next 8-bit group that has at least one set bit. The for_each_set_clump8 macro has four parameters: * start: set to the bit offset of the current clump * clump: set to the current clump value * bits: bitmap to search within * size: bitmap size in number of bits In this version of the patchset, the for_each_set_clump macro has been reimplemented and simplified based on the suggestions provided by Rasmus Villemoes and Andy Shevchenko in the version 4 submission. In particular, the function of the for_each_set_clump macro has been restricted to handle only 8-bit clumps; the drivers that use the for_each_set_clump macro only handle 8-bit ports so a generic for_each_set_clump implementation is not necessary. Thus, a solution for large clumps (i.e. those larger than the width of a bitmap word) can be postponed until a driver appears that actually requires such a generic for_each_set_clump implementation. For what it's worth, a semi-generic for_each_set_clump (i.e. for clumps smaller than the width of a bitmap word) can be implemented by simply replacing the hardcoded '8' and '0xFF' instances with respective variables. I have not yet had a need for such an implementation, and since it falls short of a true generic for_each_set_clump function, I have decided to forgo such an implementation for now. In addition, the bitmap_get_value8 and bitmap_set_value8 functions are introduced to get and set 8-bit values respectively. Their use is based on the behavior suggested in the patchset version 4 review. This patch (of 14): This macro iterates for each 8-bit group of bits (clump) with set bits, within a bitmap memory region. For each iteration, "start" is set to the bit offset of the found clump, while the respective clump value is stored to the location pointed by "clump". Additionally, the bitmap_get_value8 and bitmap_set_value8 functions are introduced to respectively get and set an 8-bit value in a bitmap memory region. [gustavo@embeddedor.com: fix potential sign-extension overflow] Link: http://lkml.kernel.org/r/20191015184657.GA26541@embeddedor [akpm@linux-foundation.org: s/ULL/UL/, per Joe] [vilhelm.gray@gmail.com: add for_each_set_clump8 documentation] Link: http://lkml.kernel.org/r/20191016161825.301082-1-vilhelm.gray@gmail.com Link: http://lkml.kernel.org/r/893c3b4f03266c9496137cc98ac2b1bd27f92c73.1570641097.git.vilhelm.gray@gmail.comSigned-off-by:Gustavo A. R. Silva <gustavo@embeddedor.com> Suggested-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Suggested-by:
Lukas Wunner <lukas@wunner.de> Tested-by:
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Joe Perches authored
Initialization is not guaranteed to zero padding bytes so use an explicit memset instead to avoid leaking any kernel content in any possible padding bytes. Link: http://lkml.kernel.org/r/dfa331c00881d61c8ee51577a082d8bebd61805c.camel@perches.comSigned-off-by:
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Nathan Chancellor authored
When building with clang + -Wtautological-pointer-compare, these instances pop up: kernel/profile.c:339:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (prof_cpu_mask != NULL) ^~~~~~~~~~~~~ ~~~~ kernel/profile.c:376:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (prof_cpu_mask != NULL) ^~~~~~~~~~~~~ ~~~~ kernel/profile.c:406:26: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (!user_mode(regs) && prof_cpu_mask != NULL && ^~~~~~~~~~~~~ ~~~~ 3 warnings generated. This can be addressed with the cpumask_available helper, introduced in commit f7e30f01 ("cpumask: Add helper cpumask_available()") to fix warnings like this while keeping the code the same. Link: https://github.com/ClangBuiltLinux/linux/issues/747 Link: http://lkml.kernel.org/r/20191022191957.9554-1-natechancellor@gmail.comSigned-off-by:Nathan Chancellor <natechancellor@gmail.com> Reviewed-by:
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Xiaoming Ni authored
blocking_notifier_chain_cond_register() does not consider system_booting state, which is the only difference between this function and blocking_notifier_cain_register(). This can be a bug and is a piece of duplicate code. Delete blocking_notifier_chain_cond_register() Link: http://lkml.kernel.org/r/1568861888-34045-4-git-send-email-nixiaoming@huawei.comSigned-off-by:
Xiaoming Ni <nixiaoming@huawei.com> Reviewed-by:
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Xiaoming Ni authored
The only difference between notifier_chain_cond_register() and notifier_chain_register() is the lack of warning hints for duplicate registrations. Use notifier_chain_register() instead of notifier_chain_cond_register() to avoid duplicate code Link: http://lkml.kernel.org/r/1568861888-34045-3-git-send-email-nixiaoming@huawei.comSigned-off-by:
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Xiaoming Ni authored
Registering the same notifier to a hook repeatedly can cause the hook list to form a ring or lose other members of the list. case1: An infinite loop in notifier_chain_register() can cause soft lockup atomic_notifier_chain_register(&test_notifier_list, &test1); atomic_notifier_chain_register(&test_notifier_list, &test1); atomic_notifier_chain_register(&test_notifier_list, &test2); case2: An infinite loop in notifier_chain_register() can cause soft lockup atomic_notifier_chain_register(&test_notifier_list, &test1); atomic_notifier_chain_register(&test_notifier_list, &test1); atomic_notifier_call_chain(&test_notifier_list, 0, NULL); case3: lose other hook test2 atomic_notifier_chain_register(&test_notifier_list, &test1); atomic_notifier_chain_register(&test_notifier_list, &test2); atomic_notifier_chain_register(&test_notifier_list, &test1); case4: Unregister returns 0, but the hook is still in the linked list, and it is not really registered. If you call notifier_call_chain after ko is unloaded, it will trigger oops. If the system is configured with softlockup_panic and the same hook is repeatedly registered on the panic_notifier_list, it will cause a loop panic. Add a check in notifier_chain_register(), intercepting duplicate registrations to avoid infinite loops Link: http://lkml.kernel.org/r/1568861888-34045-2-git-send-email-nixiaoming@huawei.comSigned-off-by:Vasily Averin <vvs@virtuozzo.com> Reviewed-by:
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