community_0_headers_kernel

headers: kernel

Community 0 | 137 files | cohesion 0.90

Definition

This community groups 137 file(s) rooted at headers with dominant language c (cohesion 0.90). Central symbols: A20_CONTROL_PORT, A20_ENABLE_BIT, A20_RESET_CLEAR_MASK, ALIGN_UP, AP_STUB_ADDR, ARCH_X86_CPU_SETUP_H, ARCH_X86_MSR_H, BC_LINE. Core file: headers/kernel.h (412 symbols). Documented purpose: SMP application-processor bootstrap stub..

Files

headers (41 files)

File	Language	Layer	Symbols	Doc
headers/ap_stub.h	h	testing	0	yes
headers/block.h	h	utility	14	yes

tests (23 files)

File	Language	Layer	Symbols	Doc
tests/test_driver.c	c	testing	5	yes
tests/test_ext4.c	c	testing	31	yes

kernel (21 files)

File	Language	Layer	Symbols	Doc
kernel/console.c	c	utility	29	yes
kernel/console_in.c	c	utility	32	yes

drivers (15 files)

File	Language	Layer	Symbols	Doc
drivers/block.c	c	infrastructure	19	yes
drivers/driver.c	c	infrastructure	8	yes

headers/drivers (10 files)

File	Language	Layer	Symbols	Doc
headers/drivers/kbd.h	h	infrastructure	24	yes
headers/drivers/modifiers.h	h	infrastructure	11	yes

fs (7 files)

File	Language	Layer	Symbols	Doc
fs/ext4.c	c	utility	38	yes

. (4 files)

File	Language	Layer	Symbols	Doc
kernel.c	c	utility	15	yes

kernel/mm (4 files)

File	Language	Layer	Symbols	Doc
kernel/mm/cow.c	c	utility	28	yes

headers/arch/x86 (3 files)

File	Language	Layer	Symbols	Doc
headers/arch/x86/cpu_setup.h	h	infrastructure	2	yes

arch/x86 (2 files)

File	Language	Layer	Symbols	Doc
arch/x86/ap_entry.S	S	utility	9	yes

arch/x86/boot (2 files)

File	Language	Layer	Symbols	Doc
arch/x86/boot/stage1.S	S	utility	11	yes

net (2 files)

File	Language	Layer	Symbols	Doc
net/net.c	c	utility	157	yes

headers/arch/x86/boot (1 files)

File	Language	Layer	Symbols	Doc
headers/arch/x86/boot/bootdefs.h	h	utility	157	yes

headers/kernel (1 files)

File	Language	Layer	Symbols	Doc
headers/kernel/console_in.h	h	utility	12	yes

headers/net (1 files)

File	Language	Layer	Symbols	Doc
headers/net/rtl8139.h	h	utility	8	no

... and 117 more files in this community.

Key Symbols

• ap_stub_start (function, arch/x86/ap_entry.S:21)
• ap_pm (function, arch/x86/ap_entry.S:39)
• ap_lm (function, arch/x86/ap_entry.S:62)
• ap_patch_slot (function, arch/x86/ap_entry.S:80)
• ap_gdt32 (function, arch/x86/ap_entry.S:84)
• ap_gdt32_ptr (function, arch/x86/ap_entry.S:88) - movw %ax, %ss /* Load smp_ap_entry()'s address from the BSP-patched slot and go. mov ap_patch_slot(%
• ap_gdt32_end (function, arch/x86/ap_entry.S:91)
• ap_gdt64_ptr (function, arch/x86/ap_entry.S:93)
• ap_stub_end (function, arch/x86/ap_entry.S:98)
• main (function, arch/x86/boot/stage1.S:28)
• normalize (function, arch/x86/boot/stage1.S:32)
• no_extensions (function, arch/x86/boot/stage1.S:78)
• read_failed (function, arch/x86/boot/stage1.S:82)
• fail (function, arch/x86/boot/stage1.S:85)
• halt (function, arch/x86/boot/stage1.S:88)
• puts (function, arch/x86/boot/stage1.S:93)
• puts_next (function, arch/x86/boot/stage1.S:97)
• puts_done (function, arch/x86/boot/stage1.S:103)
• msg_no_lba (function, arch/x86/boot/stage1.S:107)
• msg_read (function, arch/x86/boot/stage1.S:109)
• stage2_main (function, arch/x86/boot/stage2.S:39)
• a20_ready (function, arch/x86/boot/stage2.S:54)
• load_chunk (function, arch/x86/boot/stage2.S:69)
• chunk_size_ready (function, arch/x86/boot/stage2.S:74)
• read_piece (function, arch/x86/boot/stage2.S:81)
• piece_size_ready (function, arch/x86/boot/stage2.S:86)
• chunk_copy (function, arch/x86/boot/stage2.S:118)
• chunk_leave_pm (function, arch/x86/boot/stage2.S:131)
• chunk_resume (function, arch/x86/boot/stage2.S:141)
• enter_long_mode (function, arch/x86/boot/stage2.S:162)

Internal vs External Edges

• Internal resolved imports (EXTRACTED): 319
• Cross-boundary resolved imports (EXTRACTED): 37

Connections

• [EXTRACTED] depends_on community 0 <-> 5 (strength 0.9): Extracted import edge crosses communities: drivers/kbd.c imports headers/wm_events.h.
• [EXTRACTED] depends_on community 0 <-> 2 (strength 0.9): Extracted import edge crosses communities: drivers/pcm2.c imports headers/pcm_ring.h.
• [EXTRACTED] depends_on community 4 <-> 0 (strength 0.9): Extracted import edge crosses communities: headers/tls_port.h imports headers/kernel.h.
• [EXTRACTED] depends_on community 0 <-> 8 (strength 0.9): Extracted import edge crosses communities: kernel/sched.c imports headers/tick.h.
• [EXTRACTED] depends_on community 0 <-> 7 (strength 0.9): Extracted import edge crosses communities: kernel/syscalls.c imports headers/batch.h.
• [INFERRED] shares_context community 0 <-> 6 (strength 0.5): Inferred shared context (layer utility) with no import path between community 0 (headers: kernel) and community 6 (progs/doomgeneric: net_defs).
• [INFERRED] shares_context community 0 <-> 9 (strength 0.5): Inferred shared context (layer utility) with no import path between community 0 (headers: kernel) and community 9 (tools: doom_pwad).
• [INFERRED] shares_context community 0 <-> 10 (strength 0.5): Inferred shared context (language c and layer utility) with no import path between community 0 (headers: kernel) and community 10 (orphans).

Risks

• [dataflow DEAD_STORE] drivers/sb16.c:259 sb16_pump dst: dst assigned at line 259 but never read afterwards.
• [dataflow DEAD_STORE] drivers/sb16.c:531 sb16_init major: major assigned at line 531 but never read afterwards.
• [dataflow DEAD_STORE] drivers/virtio_blk.c:169 vblk_desc d: d assigned at line 169 but never read afterwards.
• [dataflow DEAD_STORE] drivers/virtio_blk.c:189 vblk_avail_push a: a assigned at line 189 but never read afterwards.
• [dataflow DEAD_STORE] drivers/virtio_net.c:146 vnet_desc d: d assigned at line 146 but never read afterwards.
• [dataflow DEAD_STORE] fs/kfile.c:103 kpipe_pair ref: ref assigned at line 103 but never read afterwards.
• [dataflow UNINIT_USE] kernel/loader.c:932 ldso_bind_into symname: symname may be read before initialization (declared line 896).
• [dataflow DEAD_STORE] kernel/loader.c:1278 load_exec_elf base: base assigned at line 1278 but never read afterwards.
• [dataflow DEAD_STORE] kernel/loader.c:1283 load_exec_elf max_end: max_end assigned at line 1283 but never read afterwards.
• [dataflow DEAD_STORE] kernel/mm/cow.c:117 cow_rehash ref: ref assigned at line 117 but never read afterwards.
• [dataflow DEAD_STORE] kernel/mm/paging.c:44 mm_setup_protections pd: pd assigned at line 44 but never read afterwards.
• [dataflow DEAD_STORE] kernel/mm/paging.c:686 honest pt: pt assigned at line 686 but never read afterwards.
• [dataflow DEAD_STORE] kernel/sched.c:632 irqstat_report txf: txf assigned at line 632 but never read afterwards.
• [dataflow DEAD_STORE] kernel/sched.c:1399 syscall wheel: wheel assigned at line 1399 but never read afterwards.
• [dataflow DEAD_STORE] kernel/sched.c:2080 proc_spawn_elf_inner frame: frame assigned at line 2080 but never read afterwards.

Open Questions

• Why do 14 file(s) lack file-level docs (e.g. arch/x86/syscall_entry.S)? What purpose do they serve?
• What would break if the most connected file in headers: kernel changed?
• Should headers: kernel be split, given cohesion 0.90?

Sources

• arch/x86/ap_entry.S
• arch/x86/boot/stage1.S
• arch/x86/boot/stage2.S
• arch/x86/syscall_entry.S
• drivers/block.c
• drivers/driver.c
• drivers/ide.c
• drivers/kbd.c
• drivers/mouse.c
• drivers/nvme.c
• drivers/pcm2.c
• drivers/pcspk.c
• drivers/rtc.c
• drivers/sb16.c
• drivers/usbblk.c
• drivers/usbhid.c
• drivers/virtio_blk.c
• drivers/virtio_net.c
• drivers/xhci.c
• fs/ext4.c
• ... and 117 more