https://www.emblogic.com/forum/categories/009-01-introduction-to-device-drivers/feed.rss Mon, 07 Sep 26 23:40:23 -0400 Interview Questions: Chacacter Device Drivers Development - EmbLogic en-CA https://www.emblogic.com/forum/discussion/2229/005-01-004-why-match-kernel-headers-and-how-do-cdev-apis-ensure-safe-character-driver-teardown Sun, 14 Jun 2026 13:51:05 -0400 pravjot 2229@/forum/discussions https://www.emblogic.com/forum/discussion/2228/005-01-003-crash-prevention-cleanup-sequence Sat, 13 Jun 2026 17:41:29 -0400 pravjot 2228@/forum/discussions https://www.emblogic.com/forum/discussion/2226/005-01-001-kernel-header-alignment-versioning Sat, 13 Jun 2026 17:33:37 -0400 pravjot 2226@/forum/discussions https://www.emblogic.com/forum/discussion/2455/005-10-229-seq_file-and-binary-data-anti-patterns Mon, 22 Jun 2026 02:10:45 -0400 pravjot 2455@/forum/discussions https://www.emblogic.com/forum/discussion/2454/005-10-228-file-permissions-and-ownership-in-proc Mon, 22 Jun 2026 02:09:37 -0400 pravjot 2454@/forum/discussions https://www.emblogic.com/forum/discussion/2453/005-10-227-seq_file-stop-pointer-evaluation Mon, 22 Jun 2026 02:08:21 -0400 pravjot 2453@/forum/discussions https://www.emblogic.com/forum/discussion/2452/005-10-226-parsing-user-input-in-proc_write Mon, 22 Jun 2026 02:06:55 -0400 pravjot 2452@/forum/discussions https://www.emblogic.com/forum/discussion/2451/005-10-225-semantic-boundaries-proc-vs-sysfs Mon, 22 Jun 2026 02:05:29 -0400 pravjot 2451@/forum/discussions https://www.emblogic.com/forum/discussion/2450/005-10-224-private-data-passing-in-proc Mon, 22 Jun 2026 02:03:42 -0400 pravjot 2450@/forum/discussions https://www.emblogic.com/forum/discussion/2449/005-10-223-oversized-seq_file-output-handling Mon, 22 Jun 2026 02:02:17 -0400 pravjot 2449@/forum/discussions https://www.emblogic.com/forum/discussion/2448/005-10-222-oversized-seq_file-output-handling Mon, 22 Jun 2026 01:49:37 -0400 pravjot 2448@/forum/discussions https://www.emblogic.com/forum/discussion/2447/005-10-221-single_open-vs-seq_open Mon, 22 Jun 2026 01:47:23 -0400 pravjot 2447@/forum/discussions https://www.emblogic.com/forum/discussion/2446/005-09-220-proc-node-instantiation Mon, 22 Jun 2026 01:46:42 -0400 pravjot 2446@/forum/discussions https://www.emblogic.com/forum/discussion/2445/005-10-219-seq_file-iterator-positions Mon, 22 Jun 2026 01:45:12 -0400 pravjot 2445@/forum/discussions https://www.emblogic.com/forum/discussion/2444/005-10-218-abstraction-of-byte-tracking-in-the-show-stage Mon, 22 Jun 2026 01:40:27 -0400 pravjot 2444@/forum/discussions https://www.emblogic.com/forum/discussion/2443/005-10-217-seq_file-termination-triggers-and-resource-cleanup Mon, 22 Jun 2026 01:34:55 -0400 pravjot 2443@/forum/discussions https://www.emblogic.com/forum/discussion/2442/005-10-216-legacy-memory-inefficiencies Sun, 21 Jun 2026 22:40:41 -0400 pravjot 2442@/forum/discussions https://www.emblogic.com/forum/discussion/2441/005-10-215-concurrency-and-phantom-data Sun, 21 Jun 2026 22:34:19 -0400 pravjot 2441@/forum/discussions https://www.emblogic.com/forum/discussion/2440/005-10-214-variable-length-state-tracking Sun, 21 Jun 2026 22:32:50 -0400 pravjot 2440@/forum/discussions https://www.emblogic.com/forum/discussion/2439/005-10-213-the-paged-read-slicing-problem Sun, 21 Jun 2026 22:28:57 -0400 pravjot 2439@/forum/discussions https://www.emblogic.com/forum/discussion/2438/005-10-212-seq_open-internal-mechanics Sun, 21 Jun 2026 22:24:22 -0400 pravjot 2438@/forum/discussions https://www.emblogic.com/forum/discussion/2437/005-10-211-file_operations-delegation Sun, 21 Jun 2026 22:22:01 -0400 pravjot 2437@/forum/discussions https://www.emblogic.com/forum/discussion/2436/005-10-210-buffer-management-in-the-iterator-loop Sun, 21 Jun 2026 22:20:02 -0400 pravjot 2436@/forum/discussions https://www.emblogic.com/forum/discussion/2435/005-10-209-synchronization-in-start-and-stop Sun, 21 Jun 2026 22:17:24 -0400 pravjot 2435@/forum/discussions https://www.emblogic.com/forum/discussion/2434/005-09-208-the-paged-read-trap-and-api-purpose Sun, 21 Jun 2026 22:14:32 -0400 pravjot 2434@/forum/discussions https://www.emblogic.com/forum/discussion/2433/005-09-207-posix-error-code-routing-in-user-space-transfers Sun, 21 Jun 2026 22:08:30 -0400 pravjot 2433@/forum/discussions https://www.emblogic.com/forum/discussion/2432/005-09-206-kernel-buffer-bounds-checking Sun, 21 Jun 2026 22:05:17 -0400 pravjot 2432@/forum/discussions https://www.emblogic.com/forum/discussion/2431/005-09-205-structural-evolution-of-proc-operations Sun, 21 Jun 2026 21:55:31 -0400 pravjot 2431@/forum/discussions https://www.emblogic.com/forum/discussion/2430/005-09-204-write-execution-mechanisms Sun, 21 Jun 2026 17:43:01 -0400 pravjot 2430@/forum/discussions https://www.emblogic.com/forum/discussion/2429/005-09-203-process-lifecycle-and-namespace-mapping Sun, 21 Jun 2026 17:41:46 -0400 pravjot 2429@/forum/discussions https://www.emblogic.com/forum/discussion/2428/005-09-202-the-pseudo-filesystem-architecture Sun, 21 Jun 2026 17:39:57 -0400 pravjot 2428@/forum/discussions https://www.emblogic.com/forum/discussion/2427/005-09-201-ioctl-command-construction-and-the-_iowr-macro Sun, 21 Jun 2026 09:47:05 -0400 pravjot 2427@/forum/discussions https://www.emblogic.com/forum/discussion/2426/005-09-200-proc-read-offsets-and-infinite-loops Sun, 21 Jun 2026 09:44:17 -0400 pravjot 2426@/forum/discussions https://www.emblogic.com/forum/discussion/2425/005-09-199-architectural-trade-offs-proc-vs-ioctl Sun, 21 Jun 2026 09:34:49 -0400 pravjot 2425@/forum/discussions https://www.emblogic.com/forum/discussion/2424/005-09-198-dynamic-content-generation-vs-standard-block-io Sun, 21 Jun 2026 09:32:13 -0400 pravjot 2424@/forum/discussions https://www.emblogic.com/forum/discussion/2423/005-09-197-capability-checking-security Sun, 21 Jun 2026 05:02:40 -0400 pravjot 2423@/forum/discussions https://www.emblogic.com/forum/discussion/2422/005-09-196-bidirectional-data-transfers-_iowr Sun, 21 Jun 2026 05:01:36 -0400 pravjot 2422@/forum/discussions https://www.emblogic.com/forum/discussion/2421/005-09-195-the-arg-parameter-typing Sun, 21 Jun 2026 05:00:55 -0400 pravjot 2421@/forum/discussions https://www.emblogic.com/forum/discussion/2420/005-09-194-posix-error-codes Sun, 21 Jun 2026 05:00:00 -0400 pravjot 2420@/forum/discussions https://www.emblogic.com/forum/discussion/2419/005-09-193-the-32-bit-vs-64-bit-dilemma-compat_ioctl Sun, 21 Jun 2026 04:59:01 -0400 pravjot 2419@/forum/discussions https://www.emblogic.com/forum/discussion/2418/005-09-192-get_user-vs-copy_from_user Sun, 21 Jun 2026 04:57:56 -0400 pravjot 2418@/forum/discussions https://www.emblogic.com/forum/discussion/2417/005-09-191-memory-safety-and-user-pointers Sun, 21 Jun 2026 04:56:06 -0400 pravjot 2417@/forum/discussions https://www.emblogic.com/forum/discussion/2416/005-09-190-the-unlocked_ioctl-evolution Sun, 21 Jun 2026 04:55:22 -0400 pravjot 2416@/forum/discussions https://www.emblogic.com/forum/discussion/2415/005-09-189-why-is-it-considered-a-dangerous-anti-pattern-to-define-ioctl-commands-using-simple- Sun, 21 Jun 2026 04:53:59 -0400 pravjot 2415@/forum/discussions https://www.emblogic.com/forum/discussion/2414/005-09-188-why-do-we-use-ioctl-for-hardware-configuration-and-status-queries Sun, 21 Jun 2026 04:52:17 -0400 pravjot 2414@/forum/discussions https://www.emblogic.com/forum/discussion/2413/005-09-187-pre-routing-security-and-magic-number-collisions Thu, 18 Jun 2026 22:44:42 -0400 pravjot 2413@/forum/discussions https://www.emblogic.com/forum/discussion/2412/005-09-186-unsynchronized-global-state-in-unlocked_ioctl- Thu, 18 Jun 2026 22:43:39 -0400 pravjot 2412@/forum/discussions https://www.emblogic.com/forum/discussion/2411/005-09-185ioctl-implementationsecure-memory-access-raw-argument-decoding-the-__user-annotation Thu, 18 Jun 2026 22:37:32 -0400 pravjot 2411@/forum/discussions https://www.emblogic.com/forum/discussion/2410/005-09-184ioctl-implementation-secure-memory-access-primitive-vs-complex-memory-transfer-macros Thu, 18 Jun 2026 22:33:48 -0400 pravjot 2410@/forum/discussions https://www.emblogic.com/forum/discussion/2409/005-09-183-sequence-number-bounds-checking Thu, 18 Jun 2026 22:28:57 -0400 pravjot 2409@/forum/discussions https://www.emblogic.com/forum/discussion/2408/005-09-182-bi-directional-data-exchange-and-struct-sizing Thu, 18 Jun 2026 22:25:51 -0400 pravjot 2408@/forum/discussions https://www.emblogic.com/forum/discussion/2407/005-09-181-command-encoding-and-user-space-pointer-safety Thu, 18 Jun 2026 22:17:52 -0400 pravjot 2407@/forum/discussions https://www.emblogic.com/forum/discussion/2406/005-09-180-the-bkl-and-the-evolution-of-unlocked_ioctl Thu, 18 Jun 2026 22:14:23 -0400 pravjot 2406@/forum/discussions https://www.emblogic.com/forum/discussion/2405/005-08-179completions-execution-orchestration-mutex-ownership-anti-patterns-uninterruptible-tra Thu, 18 Jun 2026 22:08:00 -0400 pravjot 2405@/forum/discussions https://www.emblogic.com/forum/discussion/2404/005-08-178completions-execution-orchestration-the-lost-wakeup-race-condition-stateful-memory Thu, 18 Jun 2026 22:05:36 -0400 pravjot 2404@/forum/discussions https://www.emblogic.com/forum/discussion/2403/005-08-177-blocking-io-and-wait-queues-the-thundering-herd-and-defensive-wakeups Thu, 18 Jun 2026 21:46:06 -0400 pravjot 2403@/forum/discussions https://www.emblogic.com/forum/discussion/2402/005-08-176-blocking-io-and-wait-queues-task-states-and-signal-handling-in-blocking-io Thu, 18 Jun 2026 21:43:29 -0400 pravjot 2402@/forum/discussions https://www.emblogic.com/forum/discussion/2401/005-08-175-read-copy-update-rcu-arch-instruction-reordering-publish-subscribe-memory-barrier Thu, 18 Jun 2026 21:40:04 -0400 pravjot 2401@/forum/discussions https://www.emblogic.com/forum/discussion/2400/005-08-174-read-copy-update-rcu-architecture-grace-period-mechanics-and-preemption-violations Thu, 18 Jun 2026 21:36:58 -0400 pravjot 2400@/forum/discussions https://www.emblogic.com/forum/discussion/2399/005-08-173-sequential-locks-seqlocks-the-fatal-flaw-of-pointer-traversal Thu, 18 Jun 2026 21:24:33 -0400 pravjot 2399@/forum/discussions https://www.emblogic.com/forum/discussion/2398/005-08-172-sequential-locks-seqlocks-optimistic-concurrency-and-writer-starvation Thu, 18 Jun 2026 21:00:26 -0400 pravjot 2398@/forum/discussions https://www.emblogic.com/forum/discussion/2397/005-08-171-the-fatal-flaw-of-pointer-traversal Thu, 18 Jun 2026 03:25:13 -0400 pravjot 2397@/forum/discussions https://www.emblogic.com/forum/discussion/2396/005-08-170-optimistic-concurrency-and-writer-starvation Thu, 18 Jun 2026 03:24:05 -0400 pravjot 2396@/forum/discussions https://www.emblogic.com/forum/discussion/2395/005-08-169-lockless-first-caller-wins-execution-gates Thu, 18 Jun 2026 03:18:56 -0400 pravjot 2395@/forum/discussions https://www.emblogic.com/forum/discussion/2394/005-08-168-race-conditions-in-bitwise-status-flags Thu, 18 Jun 2026 03:16:19 -0400 pravjot 2394@/forum/discussions https://www.emblogic.com/forum/discussion/2393/005-08-167-scope-limitations-and-lockless-reference-counting Thu, 18 Jun 2026 03:12:47 -0400 pravjot 2393@/forum/discussions https://www.emblogic.com/forum/discussion/2392/005-08-166-scope-limitations-and-lockless-reference-counting Thu, 18 Jun 2026 03:10:31 -0400 pravjot 2392@/forum/discussions https://www.emblogic.com/forum/discussion/2391/005-08-165-architectural-encapsulation-and-cache-coherency-locks Thu, 18 Jun 2026 03:07:40 -0400 pravjot 2391@/forum/discussions https://www.emblogic.com/forum/discussion/2390/005-08-164-architectural-encapsulation-and-cache-coherency-locks Thu, 18 Jun 2026 03:05:04 -0400 pravjot 2390@/forum/discussions https://www.emblogic.com/forum/discussion/2389/005-08-163-how-does-write_lock_irqsave-protect-scull-topology-updates-from-concurrent-readers Thu, 18 Jun 2026 02:41:32 -0400 pravjot 2389@/forum/discussions https://www.emblogic.com/forum/discussion/2388/005-08-162-why-is-read_lock_irqsave-sufficient-in-seekdevice-even-when-filep-f_pos-is-updated Thu, 18 Jun 2026 02:40:19 -0400 pravjot 2388@/forum/discussions https://www.emblogic.com/forum/discussion/2387/005-08-161-what-is-writer-starvation-in-rwlock_t-and-how-can-it-affect-driver-stability Thu, 18 Jun 2026 02:38:03 -0400 pravjot 2387@/forum/discussions https://www.emblogic.com/forum/discussion/2386/005-08-160-when-is-rwlock_t-a-better-choice-than-spinlock_t-in-a-character-driver Thu, 18 Jun 2026 02:37:11 -0400 pravjot 2386@/forum/discussions https://www.emblogic.com/forum/discussion/2385/005-08-159-what-can-happen-if-a-driver-exits-a-spin_lock_irqsave-critical-section-without- Thu, 18 Jun 2026 02:35:17 -0400 pravjot 2385@/forum/discussions https://www.emblogic.com/forum/discussion/2384/005-08-158-why-should-copy_to_user-and-kmallocgfp_kernel-be-moved-outside-a-spinlock-protected Thu, 18 Jun 2026 02:32:48 -0400 pravjot 2384@/forum/discussions https://www.emblogic.com/forum/discussion/2383/005-08-157-what-is-the-purpose-of-the-flags-variable-in-spin_lock_irqsave Thu, 18 Jun 2026 02:31:40 -0400 pravjot 2383@/forum/discussions https://www.emblogic.com/forum/discussion/2382/005-08-156-when-should-spin_lock_irqsave-be-used-instead-of-plain-spin_lock Thu, 18 Jun 2026 02:28:15 -0400 pravjot 2382@/forum/discussions https://www.emblogic.com/forum/discussion/2381/005-08-155-why-must-a-driver-never-call-sleeping-functions-while-holding-a-spinlock_t Wed, 17 Jun 2026 17:09:35 -0400 pravjot 2381@/forum/discussions https://www.emblogic.com/forum/discussion/2380/005-08-154-when-should-a-driver-use-spin_lock_irqsave-and-spin_unlock_irqrestore Wed, 17 Jun 2026 17:07:11 -0400 pravjot 2380@/forum/discussions https://www.emblogic.com/forum/discussion/2379/005-08-153-why-are-spinlocks-used-in-interrupt-context-instead-of-mutexes-or-semaphores Wed, 17 Jun 2026 17:06:03 -0400 pravjot 2379@/forum/discussions https://www.emblogic.com/forum/discussion/2378/005-08-152-why-is-the-goto-out_mutex-cleanup-pattern-important-after-mutex_lock_interruptible-suc Wed, 17 Jun 2026 17:04:20 -0400 pravjot 2378@/forum/discussions https://www.emblogic.com/forum/discussion/2377/005-08-151-why-should-a-mutex-be-embedded-inside-each-dev-structure-instead-of-using-a-global-lock Wed, 17 Jun 2026 17:03:12 -0400 pravjot 2377@/forum/discussions https://www.emblogic.com/forum/discussion/2376/005-08-150-why-must-a-character-driver-avoid-using-mutex_lock-inside-an-interrupt-handler Wed, 17 Jun 2026 17:00:46 -0400 pravjot 2376@/forum/discussions https://www.emblogic.com/forum/discussion/2375/005-08-149-why-is-a-mutex-preferred-over-a-binary-semaphore-for-protecting-shared-driver-data Wed, 17 Jun 2026 16:59:30 -0400 pravjot 2375@/forum/discussions https://www.emblogic.com/forum/discussion/2374/005-08-148-what-does-returning-erestartsys-tell-the-vfs-after-a-lock-wait-is-interrupted Wed, 17 Jun 2026 16:49:30 -0400 pravjot 2374@/forum/discussions https://www.emblogic.com/forum/discussion/2373/005-08-147-why-should-down_read_interruptible-and-down_write_killable-be-used-instead-of-raw- Wed, 17 Jun 2026 16:48:18 -0400 pravjot 2373@/forum/discussions https://www.emblogic.com/forum/discussion/2372/005-08-146-what-should-a-driver-return-when-an-rw_semaphore-wait-is-interrupted-by-a-signal Wed, 17 Jun 2026 16:45:54 -0400 pravjot 2372@/forum/discussions https://www.emblogic.com/forum/discussion/2371/005-08-145-why-should-a-character-driver-prefer-down_read_interruptible-or-down_write_killable Wed, 17 Jun 2026 16:44:45 -0400 pravjot 2371@/forum/discussions https://www.emblogic.com/forum/discussion/2370/005-08-144-how-do-down_read-down_write-and-downgrade_write-protect-shared-driver-data Wed, 17 Jun 2026 16:42:05 -0400 pravjot 2370@/forum/discussions https://www.emblogic.com/forum/discussion/2369/005-08-143-when-should-a-char-driver-use-struct-rw_semaphore-instead-of-a-mutex-or-binary-semaphore Wed, 17 Jun 2026 16:40:59 -0400 pravjot 2369@/forum/discussions https://www.emblogic.com/forum/discussion/2368/005-08-142-why-must-down_interruptible-and-up-wrap-all-critical-paths-in-read-write- Wed, 17 Jun 2026 16:35:33 -0400 pravjot 2368@/forum/discussions https://www.emblogic.com/forum/discussion/2367/005-08-141-why-should-a-semaphore-be-embedded-inside-each-device-structure-instead-of-using-one-glo Wed, 17 Jun 2026 16:34:25 -0400 pravjot 2367@/forum/discussions https://www.emblogic.com/forum/discussion/2366/005-07-140-how-can-ebpf-maps-be-used-to-build-live-histograms-and-measure-driver-function-latency Tue, 16 Jun 2026 18:14:06 -0400 pravjot 2366@/forum/discussions https://www.emblogic.com/forum/discussion/2365/005-07-139-how-can-bpftrace-capture-only-failed-writedevice-calls-using-kretprobe-and-retval Tue, 16 Jun 2026 18:13:11 -0400 pravjot 2365@/forum/discussions https://www.emblogic.com/forum/discussion/2364/005-07-138-why-should-linux-ioctl-command-values-be-printed-in-hexadecimal-during-debugging Tue, 16 Jun 2026 18:11:35 -0400 pravjot 2364@/forum/discussions https://www.emblogic.com/forum/discussion/2363/005-07-137-how-can-bpftrace-capture-ioctl-command-arguments-from-a-live-character-driver Tue, 16 Jun 2026 18:10:37 -0400 pravjot 2363@/forum/discussions https://www.emblogic.com/forum/discussion/2362/005-07-136-what-is-the-difference-between-kprobe-and-kretprobe-in-driver-debugging Tue, 16 Jun 2026 17:36:05 -0400 pravjot 2362@/forum/discussions https://www.emblogic.com/forum/discussion/2361/005-07-135-how-does-ebpf-inspect-character-driver-function-arguments-without-recompiling-the-driver Tue, 16 Jun 2026 17:34:45 -0400 pravjot 2361@/forum/discussions https://www.emblogic.com/forum/discussion/2360/005-07-134-how-can-kernelshark-be-used-to-identify-mutex-blocking-and-io-latency Tue, 16 Jun 2026 17:32:22 -0400 pravjot 2360@/forum/discussions https://www.emblogic.com/forum/discussion/2359/005-07-133-how-does-kernelshark-help-visualize-multi-core-execution-of-a-character-driver Tue, 16 Jun 2026 17:30:55 -0400 pravjot 2359@/forum/discussions