[PATCH RESEND v2 00/23] proc: convert the arch and platform entries (Part 3/7)
From: Christian Brauner
Date: Wed Nov 04 2026 - 16:19:24 EST
Part 3/7 of "proc: move procfs to what kernfs does", on top of part 2
and independent of parts 4 to 6:
https://patch.msgid.link/20261104-work-procfs-v2-0-b45cd5789ac5@brauner
This converts the proc entries under arch/ and the ones of ACPI, the
platform drivers, via-pmu and PNP to what "proc: let procfs own the data
path" set up. Afterwards the entries' code only runs with the entry
pinned and never touches userspace memory. One patch per subsystem and
method.
- procfs copies in the writes of alpha's srm_env, the ARM and sh
alignment files, the rtas, pseries, mconsole and exitcode files,
sparc's led, /proc/mtrr, simdisk, /proc/acpi/wakeup, via-pmu's
options, thinkpad_acpi, toshiba_acpi and pnpbios. Most of them just
stop copying in themselves or switch from kstrto*_from_user() to
kstrto*(). Where a write larger than anything the entry parses now
fails with -EINVAL from procfs the commit says so.
- procfs copies out the reads of /proc/atags, /proc/bootinfo, the rtas
error log and flash files, /proc/powerpc/systemcfg, simdisk and
/proc/bus/isapnp, mostly simple_read_from_buffer() turned into
memory_read_from_buffer().
- procfs owns the seq_file of /proc/mtrr and copies its ioctl arguments
in and out. The ioctls are table driven now, the native and the 32-bit
commands share one table.
- the rtas flash files take their image in 4k pieces and keep doing that
with PROC_ENTRY_SHORT_WRITES.
- the rtas error log is a stream, it hands out a record before procfs
copies it out, so a reader that passes a bad buffer loses it. Its
pollers sleep on the wait queue procfs owns for the entry now and
rtasd wakes them with proc_poll_notify().
Build tested per commit on x86_64 and with W=1 on the touched objects on
alpha, arm, m68k, powerpc, sh, sparc, um, x86 and xtensa. The entries I
could get at in an x86 VM behave the same with and without the series.
Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
---
Changes in v2:
- rtasd lets procfs own the wait queue of the rtas error log
- rebased onto v7.4-rc1, the thinkpad_acpi write merged with its
cleanup.h restyle upstream
- Link to v1: https://patch.msgid.link/20261102-work-procfs-arch-v1-0-c9492ab08480@xxxxxxxxxx
---
Christian Brauner (23):
alpha: srm_env: let procfs copy in writes
ARM: alignment: let procfs copy in writes
ARM: atags: let procfs copy out reads of /proc/atags
m68k/bootinfo: let procfs copy out reads of /proc/bootinfo
powerpc/rtas: let procfs copy in writes
powerpc/rtas: let procfs copy out reads
powerpc/rtasd: let procfs own the wait queue of the rtas error log
powerpc/pseries: let procfs copy in writes
powerpc/procfs: let procfs copy out reads of /proc/powerpc/systemcfg
sh: alignment: let procfs copy in writes
sparc: led: let procfs copy in writes
um: let procfs copy in writes
x86/mtrr: let procfs own the seq_file of /proc/mtrr
x86/mtrr: let procfs copy in writes to /proc/mtrr
x86/mtrr: let procfs copy the ioctl arguments of /proc/mtrr
xtensa: simdisk: let procfs copy in writes
xtensa: simdisk: let procfs copy out reads
ACPI: proc: let procfs copy in writes to /proc/acpi/wakeup
macintosh/via-pmu: let procfs copy in writes to the options file
platform/x86: thinkpad_acpi: let procfs copy in writes
platform/x86: toshiba_acpi: let procfs copy in writes
PNP: pnpbios: let procfs copy in writes
PNP: isapnp: let procfs copy out reads
arch/alpha/kernel/srm_env.c | 12 +---
arch/arm/kernel/atags_proc.c | 6 +-
arch/arm/mm/alignment.c | 7 +--
arch/m68k/kernel/bootinfo_proc.c | 6 +-
arch/powerpc/kernel/proc_powerpc.c | 6 +-
arch/powerpc/kernel/rtas-proc.c | 40 ++++++------
arch/powerpc/kernel/rtas_flash.c | 62 +++++++++----------
arch/powerpc/kernel/rtasd.c | 30 +++------
arch/powerpc/platforms/pseries/lpar.c | 14 ++---
arch/powerpc/platforms/pseries/lparcfg.c | 7 +--
arch/powerpc/platforms/pseries/reconfig.c | 22 +++----
arch/sh/mm/alignment.c | 7 +--
arch/sparc/kernel/led.c | 12 +---
arch/um/drivers/mconsole_kern.c | 11 +---
arch/um/kernel/exitcode.c | 14 ++---
arch/x86/kernel/cpu/mtrr/if.c | 95 ++++++++++++++++-------------
arch/xtensa/platforms/iss/simdisk.c | 32 ++++------
drivers/acpi/proc.c | 7 +--
drivers/macintosh/via-pmu.c | 7 +--
drivers/platform/x86/lenovo/thinkpad_acpi.c | 12 +---
drivers/platform/x86/toshiba_acpi.c | 36 ++++-------
drivers/pnp/isapnp/proc.c | 20 +++---
drivers/pnp/pnpbios/proc.c | 9 +--
23 files changed, 198 insertions(+), 276 deletions(-)
---
base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
change-id: 20261101-work-procfs-arch-8d4ade48be31
prerequisite-change-id: 20261101-work-procfs-core-8fa4a4f412cf:v2
prerequisite-patch-id: a81e8b894107e48d607f8257d2c9f56e0dd6f400
prerequisite-patch-id: 7edf7ca7ecd32c9e09085e4b65922af10097beaa
prerequisite-patch-id: 81f6893f79b4236637675553298a6f2892b603f3
prerequisite-patch-id: 598c2b1a389f47adcac88ebcf1c9f74e2511fbab
prerequisite-patch-id: 6f5a2172dacc5ff2491fa9832c48ccd0e1ce1eda
prerequisite-patch-id: 8947af6490288e4e2a3b2bf8844a974bedb1d975
prerequisite-patch-id: 8cbe756286fd95967d31b0c46cacfeb05f0a2c6b
prerequisite-patch-id: 3fa159f2b6ccd0ac51a2662e4eec5587ec18de89
prerequisite-patch-id: bfb4e4ffe9631cb58015fefe6bd3698cd53e2244
prerequisite-patch-id: 56ff6667a57a962264c07c0227c61aa2f1f4c22c
prerequisite-patch-id: bc506323e29944ec0c29eae84950c706a8592042
prerequisite-patch-id: 326c0ebb5accf0f40cbee1323fb4c3378f5be154
prerequisite-patch-id: d6eaf7690a54a0dfda7500936a048b769fa265dd
prerequisite-patch-id: 7c7b2535642b4d388e13eab518cbe0f9550eb1e6
prerequisite-patch-id: 0474af12959624910718795bf86684383664c685
prerequisite-patch-id: f6d4191e23c22e2d2cc90cc5d04781f913e98a8e
prerequisite-patch-id: b0031a7c4855b7ec38259c59f30f65101a8fc4b5
prerequisite-patch-id: 0b7f226abf2b9ff41873a1aa55cf97747647d56b
prerequisite-patch-id: f63e345f897619af54813958046617c655fb7daf
prerequisite-patch-id: c0e21e762a2960e3324c5ab04634a7035e515fa6
prerequisite-patch-id: fd59c71eadd8f39c58b3baea93567bc093bc9b0e
prerequisite-patch-id: 5d52cc8a5c73e4c5ba16b8e24f51408c17583bf9
prerequisite-patch-id: 1f9179284e2f3314d4b46ac5e989089a21c7576c
prerequisite-patch-id: 10397bbf696bee16dc71eb79fff6c5e73842bcbc
prerequisite-patch-id: 9b44279dcf08912238d2f6438a3328a778a79a0c
prerequisite-patch-id: 16854b621a3a71dfc365aaf7abaa7f65adfe9f7e
prerequisite-patch-id: ca42eea21fae1fd1cd3518ab057c74b61ffd68fe
prerequisite-patch-id: 23255dc2be76b0479c083dbd4c897bfbb533aed5
prerequisite-patch-id: 82129c687ebf0a41b369893b92f2c038420ab801
prerequisite-patch-id: 56ad57a99a5bda075a9f4e844368974296744934
prerequisite-patch-id: 288b3cbaa11e01a778cc3d7beb6c0549aacf59f2
prerequisite-patch-id: a163b1549608652bfa5bd9ff93efa55b541010c4
prerequisite-patch-id: 43b92dfc1a98fbf0d14597a3e3ae99972844773b
prerequisite-patch-id: 19c12bc6e3fbed35acc1f657196b1a997f48cdfe
prerequisite-patch-id: 5800c3076694bad719954b2ad4d7448c6e013bfd
prerequisite-patch-id: 2a2f63d8843b159594b9eee6ddea028ce76a6270
prerequisite-patch-id: 40a1951d57906c4a1b98a4bd96a814b80339b9c5
prerequisite-patch-id: e2141077e69f20a2b27fab69c8d61d0686682f53
prerequisite-patch-id: c4d6018c26c40dc549d88330d23ce48f872c2b7f
prerequisite-patch-id: 6de8ec17746031bc6d1d9ac262c5be0f905fcd79
prerequisite-patch-id: b87bcb167884605bff1fd0f2ed8a88942d07efd5
prerequisite-patch-id: cfa9a8b4c67e20cfd22d77035bfd21ee96ab3298
prerequisite-patch-id: abf3482ed2399b7b2e1ee72e937af05bb9200667
prerequisite-patch-id: 02c175b2dee565a85b3308ecf2ec8e3c9a029e0f
prerequisite-patch-id: d58c239fba616b366a725de6acba3f88734156d0
prerequisite-patch-id: dbe02fe3f784776fda5e7ae99f077bef0cd4b48d
prerequisite-patch-id: 53edc9a95afff57c4acba40095a8054924261ea2
prerequisite-patch-id: 5348d8957eb7eae7430ca8b101aa84ce77d3aa4f
prerequisite-patch-id: 36c96d781e2dd80b20932667bbe6e7fd14976069
prerequisite-patch-id: efeb2d6f7df71d5dede2c1d12fe999a28e38aab9
prerequisite-patch-id: 17f95c7fdf0bdc7c8aaaf7883bff1dcc19a0f529
prerequisite-patch-id: 117db27dcdef433de7c6be5e95973cac1e373927
prerequisite-patch-id: a0844aa26ffb65ccb362b88ef6c2f4758e15edbf
prerequisite-patch-id: 9c64355dfde62e399f2717d9208c4607834d4650
prerequisite-patch-id: 9644739854ddfe2876f17fda8727fd5119255957
prerequisite-patch-id: c61bba24c035f79a2a32a80ace0924ab58e97f46
prerequisite-patch-id: 143fb91bddf33068b6ee11e205818c4c2815e23d
prerequisite-patch-id: 9ce9be2ff05250f92d945c0084f4bb31d3d0b27d
prerequisite-patch-id: aee0961341523547095a43ae298cb8b551302f10
prerequisite-patch-id: 2f0fdb970ddd760d85ff5d2caad0b96348270182
prerequisite-patch-id: f2aa468ff5cbb1cabab3f70e1b8eeee0286cfb4a
prerequisite-patch-id: 5555895bcbca4d7c9888ecc9e82c0e4d76da8f40
prerequisite-patch-id: 487141c49e2548310bfb6c2a0964a78f08b285a9
prerequisite-patch-id: c3d3008819fa5629a18142ec9ba6d7024ade7fdb
prerequisite-patch-id: ca587c976690ac16e3d759fccab2116fef0508e8
prerequisite-patch-id: 9423f410b99853693db06c29f12f1c08278b050d
prerequisite-patch-id: e269815617a6324615a38916b8886f99d98c641e
prerequisite-patch-id: 3d24be1897a624d519ef144801f76d152c7528a9
prerequisite-patch-id: 1ea3fc8319d9012faaf3a182ac61d5da89aafdb7
prerequisite-patch-id: 7547b4e2c1b3588acf6caf90cc01fe7884fdb6bd
prerequisite-patch-id: 695d325349ebeb89bf0ea24bcf0c4f1c4edacab5
prerequisite-patch-id: e33502a202979aba0d6fdaf196e8471d906992a1
prerequisite-patch-id: 47bfe4f07677ad75fe8d9accc8923a1cbdf3afa6
prerequisite-patch-id: 9fc0739226572203fcb36f2c271be7b27f405ef2