kernel/linux.git/include/linux/init_task.h, branch v6.19.11

cred: make init_cred static

2025-11-04T11:36:02+00:00

There's zero need to expose struct init_cred. The very few places that need access can just go through init_task which is already exported. Link: https://patch.msgid.link/20251103-work-creds-init_cred-v1-3-cb3ec8711a6a@kernel.org Reviewed-by: Jens Axboe Signed-off-by: Christian Brauner

arch: remove ARCH_TASK_STRUCT_ON_STACK

2023-12-11T01:21:31+00:00

IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ON_STACK. IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Therefore remove support for ARCH_TASK_STRUCT_ON_STACK as well. Note: this also reveals a potential bug in powerpc code, which makes use of __init_task_data without selecting ARCH_TASK_STRUCT_ON_STACK which makes __init_task_data a no-op. This is broken since commit d11ed3ab3166 ("Expand INIT_TASK() in init/init_task.c and remove") from 2018 and needs to be addressed separately. Link: https://lkml.kernel.org/r/20231116133638.1636277-4-hca@linux.ibm.com Signed-off-by: Heiko Carstens Reviewed-by: Arnd Bergmann Cc: Michael Ellerman Cc: Nicholas Piggin Signed-off-by: Andrew Morton

kernel/cred.c: make init_groups static

2021-05-07T02:24:11+00:00

init_groups is declared in both cred.h and init_task.h, but it is not actually referenced anywhere outside of cred.c where it is defined. So make it static and remove the declarations. Link: https://lkml.kernel.org/r/20210310220102.2484201-1-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49+00:00

Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Linus Torvalds

posix-cpu-timers: Create a container struct

2019-08-28T09:50:33+00:00

Per task/process data of posix CPU timers is all over the place which makes the code hard to follow and requires ifdeffery. Create a container to hold all this information in one place, so data is consolidated and the ifdeffery can be confined to the posix timer header file and removed from places like fork. As a first step, move the cpu_timers list head array into the new struct and clean up the initializers and simplify fork. The remaining #ifdef in fork will be removed later. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lkml.kernel.org/r/20190821192920.819418976@linutronix.de

sched/core: Convert task_struct.stack_refcount to refcount_t

2019-02-04T07:53:56+00:00

atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable task_struct.stack_refcount is used as pure reference counter. Convert it to refcount_t and fix up the operations. ** Important note for maintainers: Some functions from refcount_t API defined in lib/refcount.c have different memory ordering guarantees than their atomic counterparts. The full comparison can be seen in https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon in state to be merged to the documentation tree. Normally the differences should not matter since refcount_t provides enough guarantees to satisfy the refcounting use cases, but in some rare cases it might matter. Please double check that you don't have some undocumented memory guarantees for this variable usage. For the task_struct.stack_refcount it might make a difference in following places: - try_get_task_stack(): increment in refcount_inc_not_zero() only guarantees control dependency on success vs. fully ordered atomic counterpart - put_task_stack(): decrement in refcount_dec_and_test() only provides RELEASE ordering and control dependency on success vs. fully ordered atomic counterpart Suggested-by: Kees Cook Signed-off-by: Elena Reshetova Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: David Windsor Reviewed-by: Hans Liljestrand Reviewed-by: Andrea Parri Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akpm@linux-foundation.org Cc: viro@zeniv.linux.org.uk Link: https://lkml.kernel.org/r/1547814450-18902-6-git-send-email-elena.reshetova@intel.com Signed-off-by: Ingo Molnar

pids: Move the pgrp and session pid pointers from task_struct to signal_struct

2018-07-21T15:43:12+00:00

To access these fields the code always has to go to group leader so going to signal struct is no loss and is actually a fundamental simplification. This saves a little bit of memory by only allocating the pid pointer array once instead of once for every thread, and even better this removes a few potential races caused by the fact that group_leader can be changed by de_thread, while signal_struct can not. Signed-off-by: "Eric W. Biederman"

Expand INIT_STRUCT_PID and remove

2018-01-17T11:30:16+00:00

Expand INIT_STRUCT_PID in the single place that uses it and then remove it. There doesn't seem any point in the macro. Signed-off-by: David Howells Tested-by: Tony Luck Tested-by: Will Deacon (arm64) Tested-by: Palmer Dabbelt Acked-by: Thomas Gleixner

Expand the INIT_SIGNALS and INIT_SIGHAND macros and remove

2018-01-17T11:30:16+00:00

There doesn't seem to be any need to have the INIT_SIGNALS and INIT_SIGHAND macros, so expand them in their single places of use and remove them. Signed-off-by: David Howells Tested-by: Tony Luck Tested-by: Will Deacon (arm64) Tested-by: Palmer Dabbelt Acked-by: Thomas Gleixner

Expand various INIT_* macros and remove

2018-01-17T11:30:16+00:00

Expand various INIT_* macros into the single places they're used in init/init_task.c and remove them. Signed-off-by: David Howells Tested-by: Tony Luck Tested-by: Will Deacon (arm64) Tested-by: Palmer Dabbelt Acked-by: Thomas Gleixner

kernel/linux.git/include/linux/init_task.h, branch v6.19.11

cred: make init_cred static

arch: remove ARCH_TASK_STRUCT_ON_STACK

kernel/cred.c: make init_groups static

treewide: Convert macro and uses of __section(foo) to __section("foo")

posix-cpu-timers: Create a container struct

sched/core: Convert task_struct.stack_refcount to refcount_t

pids: Move the pgrp and session pid pointers from task_struct to signal_struct

Expand INIT_STRUCT_PID and remove

Expand the INIT_SIGNALS and INIT_SIGHAND macros and remove

Expand various INIT_* macros and remove

treewide: Convert macro and uses of section(foo) to section("foo")