fix: procfs #32

kwrx · 2026-01-15T20:18:48Z

This pull request introduces several improvements and fixes across the drivers and build system, with a particular focus on the virtio GPU driver, PCI MSI-X handling, and debugging support. The most notable changes include a significant refactor of the virtio GPU framebuffer initialization and update logic, improvements to the PCI MSI-X interrupt handling, and the addition of more granular debug logging for PTY and other subsystems.

Virtio GPU driver improvements

Refactored the framebuffer initialization in virtio-gpu/main.c to use a dynamic resource ID (virtgpu_fb_resid) and removed hardcoded macros and unused code, improving resource management and readability. The framebuffer is now created, attached, and set as the scanout in a more robust sequence, with error handling for display enablement and command failures. ([[1]](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594L56-L57), [[2]](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594R89-L105), [[3]](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594L115-L160), [[4]](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594L198-R180))
Updated the vsync and framebuffer flush logic to use the new dynamic resource ID, ensuring correct synchronization and display updates. ([drivers/virtio/virtio-gpu/main.cL246-R231](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594L246-R231))
Cleaned up verbose debug output and assertions in interrupt and PCI device discovery handlers for the GPU driver. ([drivers/virtio/virtio-gpu/main.cL296-L320](https://github.com/kwrx/aplus/pull/32/files#diff-ea594d89bf0752573aa484e356e537c8f0c900f6957d07f27bad22c974c5e594L296-L320))
Removed unnecessary debug prints and blank lines in virtgpu_cmd.c, streamlining resource management commands and improving maintainability. ([[1]](https://github.com/kwrx/aplus/pull/32/files#diff-4fd1958662a1c8900ddb55ee008bf7b2fdc0bd6be1f19faa45ac783b84908a96L48-L59), [[2]](https://github.com/kwrx/aplus/pull/32/files#diff-4fd1958662a1c8900ddb55ee008bf7b2fdc0bd6be1f19faa45ac783b84908a96L68-L79), [[3]](https://github.com/kwrx/aplus/pull/32/files#diff-4fd1958662a1c8900ddb55ee008bf7b2fdc0bd6be1f19faa45ac783b84908a96L88-L96), [[4]](https://github.com/kwrx/aplus/pull/32/files#diff-4fd1958662a1c8900ddb55ee008bf7b2fdc0bd6be1f19faa45ac783b84908a96L105-L128), [[5]](https://github.com/kwrx/aplus/pull/32/files#diff-4fd1958662a1c8900ddb55ee008bf7b2fdc0bd6be1f19faa45ac783b84908a96L138-L158))

PCI MSI-X interrupt handling

Added memory zeroing for MSI-X tables and PBA in pci_msix.c to ensure a clean state before masking interrupts, improving reliability. ([drivers/dev/pci/pci_msix.cR116-R118](https://github.com/kwrx/aplus/pull/32/files#diff-f93480b8db103254db27bd9cb9be59fc00eac5e87f8c7c48e3092678717dde4cR116-R118))
Fixed the interrupt mapping and unmapping logic by adding missing break statements, preventing unnecessary iterations and possible bugs. ([[1]](https://github.com/kwrx/aplus/pull/32/files#diff-f93480b8db103254db27bd9cb9be59fc00eac5e87f8c7c48e3092678717dde4cR203), [[2]](https://github.com/kwrx/aplus/pull/32/files#diff-f93480b8db103254db27bd9cb9be59fc00eac5e87f8c7c48e3092678717dde4cR244))

Debug logging enhancements

Added conditional debug logging to PTY input processing, including discard, signal sending, canonical mode handling, and character processing, gated by DEBUG_LEVEL_TRACE for easier troubleshooting. ([[1]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dL67-R69), [[2]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR192-R194), [[3]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR239-R241), [[4]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR255-R258), [[5]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR267-R276), [[6]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR293-R295), [[7]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR309-R311), [[8]](https://github.com/kwrx/aplus/pull/32/files#diff-819e605dd2015540a65582a6f1cdbe9f74f164edf009a8c8b632bc4c11c8329dR320-R348))
Fixed a preprocessor condition for VGA debug tracing to use #if instead of #ifdef, ensuring correct compilation. ([drivers/platform/pc/video/bochs-vga/main.cL269-R269](https://github.com/kwrx/aplus/pull/32/files#diff-0d242fb45fe0c16791acda4d0a7fcd7553e6ff5580dac62be83969a2f6dd1a89L269-R269))

Input and console driver fixes

Improved PS/2 mouse packet handling by resetting the cycle counter on invalid packet start, preventing input errors. ([[1]](https://github.com/kwrx/aplus/pull/32/files#diff-c1e61c0fa5b74c1b69b71bae9933ba1f87832f05208503381618b65f46411b3fL271-R274), [[2]](https://github.com/kwrx/aplus/pull/32/files#diff-c1e61c0fa5b74c1b69b71bae9933ba1f87832f05208503381618b65f46411b3fL382))
Updated the virtio console write logic to respect the driver's send window size, sending data in appropriately sized chunks and improving reliability for large writes. ([drivers/virtio/virtio-console/main.cR152-R169](https://github.com/kwrx/aplus/pull/32/files#diff-bf73670fc756b476b8c6b0195b42973c48cbd2bfffd708f08139789063dd83d9R152-R169))

Build system updates

Added necessary include paths and compiler flags to the Makefile for the kilo app, ensuring proper compilation in cross-build environments. ([apps/extra/kilo/MakefileR1-R5](https://github.com/kwrx/aplus/pull/32/files#diff-0130715cda0bcbb04c66dda8ef166a8c7fbf9db8720d7d9dbec6337133e4b628R1-R5))

…ommon_cfg

…sistency

…refix

Copilot

Pull request overview

This pull request enhances the procfs filesystem implementation with new service files (version, filesystems), adds proper error handling for virtio MSI-X vector mapping, updates spinlock memory order semantics for correctness, and fixes several bugs in procfs directory operations.

Changes:

Added error handling for MSI-X vector mapping failures in virtio-pci initialization
Implemented new procfs service files (/proc/version, /proc/filesystems) with proper filesystem table exposure
Updated atomic memory ordering in spinlock operations from deprecated memory_order_consume to memory_order_acquire and added release semantics
Fixed multiple bugs in procfs readdir implementation (wrong task/offset usage) and converted cache spinlock to recursive mode

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
drivers/virtio/virtio-pci/main.c	Added error handling for MSI-X vector mapping with proper status reporting
kernel/ipc/spinlock.c	Updated memory order semantics for atomic operations (acquire/release)
kernel/syscalls/257_openat.c	Added 'syscall:' prefix to debug output for consistency
libk/utils/cache.c	Changed to recursive spinlock and removed unnecessary key assertions
kernel/fs/vfs.c	Refactored filesystem table from static array to exposed global structure
kernel/fs/fstable.c.in	Added nodev attribute to filesystem entries
include/aplus/vfs.h	Added fstable_t type definition and VFS_MAX_FILESYSTEMS constant
kernel/fs/procfs/procfs_service_version.c	New file implementing /proc/version service
kernel/fs/procfs/procfs_service_filesystems.c	New file implementing /proc/filesystems service
kernel/fs/procfs/procfs_root_getattr.c	New file implementing getattr for procfs root
kernel/fs/procfs/procfs_service_pid.c	Fixed finddir to check inode->name instead of unused name parameter
kernel/fs/procfs/procfs_root_readdir.c	Fixed task variable usage and d_off field to use index instead of pos
kernel/fs/procfs/procfs_root_finddir.c	Uncommented version and filesystems service lookups
kernel/fs/procfs/procfs_mount.c	Enabled getattr operation for procfs root
kernel/fs/procfs/procfs.h	Added function declarations for new service files
kernel/fs/procfs/procfs_service_{uptime,meminfo,cmdline}.c	Removed overly restrictive inode->sb->root assertions

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Copilot · 2026-01-15T20:21:40Z

kernel/fs/procfs/procfs_service_pid.c

+    if (isdigit(inode->name[0])) {
+
+        long pid = atol(inode->name);
+
+        if (pid > 0) {
+            return procfs_service_pid_inode(inode, pid);
+        } else {
+            return errno = ENOENT, NULL;
+        }
+
+    } else if(strcmp(inode->name, "self") == 0) {
+        return procfs_service_pid_inode(inode, current_task->tid);
+    } else {
+        return errno = ENOENT, NULL;
+    }


The function procfs_service_pid_finddir receives a parameter 'name' but checks 'inode->name' instead. This appears to be incorrect - the function should be checking the 'name' parameter to determine which child entry to find within the current inode directory, not the inode's own name. This logic should match the pattern in procfs_root_finddir which correctly uses the 'name' parameter.

Copilot · 2026-01-15T20:21:40Z

kernel/fs/procfs/procfs_service_pid.c

+            return errno = ENOENT, NULL;
+        }
+
+    } else if(strcmp(inode->name, "self") == 0) {


Missing space after 'if' keyword. Should be 'if (' instead of 'if(' to match the coding style used throughout the rest of the codebase.

Suggested change

} else if(strcmp(inode->name, "self") == 0) {

} else if (strcmp(inode->name, "self") == 0) {

Copilot · 2026-01-15T20:21:40Z

kernel/fs/procfs/procfs_root_finddir.c


-        // if(strcmp(name, "version") == 0)
-        //     return procfs_version_inode();
+        if(strcmp(name, "version") == 0)


Missing space after 'if' keyword. Should be 'if (' instead of 'if(' to match the coding style used in surrounding code (see lines 61, 67, 70, 79).

Copilot · 2026-01-15T20:21:41Z

kernel/fs/procfs/procfs_root_finddir.c


-        // if(strcmp(name, "filesystems") == 0)
-        //     return procfs_filesystems_inode();
+        if(strcmp(name, "filesystems") == 0)


Missing space after 'if' keyword. Should be 'if (' instead of 'if(' to match the coding style used in surrounding code.

Copilot · 2026-01-15T20:21:41Z

kernel/fs/procfs/procfs_service_filesystems.c

+
+    static char buffer[BUFSIZ] = {0};
+
+    for(size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {


Missing space after 'for' keyword. Should be 'for (' instead of 'for(' to maintain consistent coding style.

Suggested change

for(size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {

for (size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {

Copilot · 2026-01-15T20:21:41Z

drivers/virtio/virtio-pci/main.c

        uint16_t i = k % (vector_limit - 1);

-        pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i);
+        if(pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i) < 0) {


Missing space after 'if' keyword. Should be 'if (' instead of 'if(' to maintain consistent coding style.

Suggested change

if(pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i) < 0) {

if (pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i) < 0) {

Copilot · 2026-01-15T20:21:41Z

drivers/virtio/virtio-pci/main.c

    }

-    pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, vector_limit - 1);
+    if(pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, vector_limit - 1) < 0) {


Missing space after 'if' keyword. Should be 'if (' instead of 'if(' to maintain consistent coding style.

… handling

… initialization

…mation

…rite syscall

… size checks

…window management

kwrx added 4 commits January 15, 2026 21:17

fix: add error handling for MSI-X vector mapping in virtio_pci_init_c…

c5fc30f

…ommon_cfg

fix: enhance procfs with new filesystem services and attributes

f61203b

fix: update memory order semantics in spinlock implementation for con…

a159ea6

…sistency

chore: update debug output for openat syscall to include 'syscall:' p…

1a4452c

…refix

kwrx requested a review from Copilot January 15, 2026 20:18

kwrx self-assigned this Jan 15, 2026

kwrx added the enhancement label Jan 15, 2026

Copilot started reviewing on behalf of kwrx January 15, 2026 20:19 View session

Copilot AI reviewed Jan 15, 2026

View reviewed changes

kwrx added 18 commits January 15, 2026 21:22

fix: update memory info fetch to include additional metrics in procfs

d0bce19

fix: initialize MSI-X rows and PBA to zero in pci_find_msix function

ffec9e5

chore: add kilo editor

4e54346

fix: reset cycle variable in ps2_mouse_irq function for proper packet…

08e742f

… handling

fix: update preprocessor directive for DEBUG_LEVEL_TRACE in bochs-vga…

0ab65b7

… initialization

fix: enhance DEBUG_LEVEL_TRACE logging in pty input processing

6a20a81

fix: refactor virtio-gpu framebuffer handling and command functions

12a9e8c

fix: change return type of spinlock_trylock to bool for clarity

8025773

fix: add prototype for virtgpu_cmd_resource_flush function

c4fe046

fix: improve logging output in kmain function for better system infor…

b5bc1f3

…mation

fix: streamline task scheduling logic in the schedule function

51ecb3e

fix: ensure CPU online message is printed only in debug mode

d5151bb

fix: adjust indentation for consistency in network_init function

c25a6c9

fix: remove redundant preprocessor directive for network support in w…

f17e101

…rite syscall

fix: enhance spinlock locking mechanism and update trylock return type

1e94652

fix: update assertions in virtq_sendrecv and virtq_recv for inclusive…

b853afb

… size checks

fix: improve virtconsole_write to handle larger data sizes with send …

45ad1bb

…window management

fix: add debug logging for waking up waiter tasks in exit syscall

fd2b82f

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fix: procfs #32

fix: procfs #32

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kwrx commented Jan 15, 2026 •

edited

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	} else if(strcmp(inode->name, "self") == 0) {
	} else if (strcmp(inode->name, "self") == 0) {


		static char buffer[BUFSIZ] = {0};

		for(size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {

	for(size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {
	for (size_t i = 0; i < VFS_MAX_FILESYSTEMS; i++) {

	if(pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i) < 0) {
	if (pci_msix_map_irq(driver->device, &msix, (pci_irq_handler_t)virtio_pci_interrupt, (pci_irq_data_t)driver, i) < 0) {

fix: procfs #32

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fix: procfs #32

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kwrx commented Jan 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Virtio GPU driver improvements

PCI MSI-X interrupt handling

Debug logging enhancements

Input and console driver fixes

Build system updates

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kwrx commented Jan 15, 2026 •

edited

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