linux.git/arch/um/include/asm/thread_info.h, branch v6.2

ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP

2022-05-11T19:33:33+00:00

User mode linux is the last user of the PT_DTRACE flag.  Using the flag to indicate
single stepping is a little confusing and worse changing tsk->ptrace without locking
could potentionally cause problems.

So use a thread info flag with a better name instead of flag in tsk->ptrace.

Remove the definition PT_DTRACE as uml is the last user.

Cc: stable@vger.kernel.org
Acked-by: Johannes Berg 
Tested-by: Kees Cook 
Reviewed-by: Oleg Nesterov 
Link: https://lkml.kernel.org/r/20220505182645.497868-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman"

um: remove set_fs

2021-12-22T16:56:56+00:00

Remove address space overrides using set_fs() for User Mode Linux.
Note that just like the existing kernel access case of the uaccess
routines the new nofault kernel handlers do not actually have any
exception handling.  This is probably broken, but not change to the
status quo.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Richard Weinberger

um: add support for TIF_NOTIFY_SIGNAL

2020-11-09T15:16:55+00:00

Wire up TIF_NOTIFY_SIGNAL handling for um.

Cc: linux-um@lists.infradead.org
Acked-By: Anton Ivanov 
Signed-off-by: Jens Axboe

um: Add SPDX headers for files in arch/um/include

2019-09-15T19:37:17+00:00

Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar 
Signed-off-by: Richard Weinberger

Construct init thread stack in the linker script rather than by union

2018-01-09T23:21:02+00:00

Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells 
Tested-by: Tony Luck 
Tested-by: Will Deacon  (arm64)
Tested-by: Palmer Dabbelt 
Acked-by: Thomas Gleixner

um: Fix FP register size for XSTATE/XSAVE

2017-09-13T20:24:38+00:00

Hard code max size. Taken from
https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdb/common/x86-xstate.h

Signed-off-by: Thomas Meyer 
Signed-off-by: Richard Weinberger

um: Add seccomp support

2016-01-10T20:49:49+00:00

This brings SECCOMP_MODE_STRICT and SECCOMP_MODE_FILTER support through
prctl(2) and seccomp(2) to User-mode Linux for i386 and x86_64
subarchitectures.

secure_computing() is called first in handle_syscall() so that the
syscall emulation will be aborted quickly if matching a seccomp rule.

This is inspired from Meredydd Luff's patch
(https://gerrit.chromium.org/gerrit/21425).

Signed-off-by: Mickaël Salaün 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: Andy Lutomirski 
Cc: Will Drewry 
Cc: Chris Metcalf 
Cc: Michael Ellerman 
Cc: James Hogan 
Cc: Meredydd Luff 
Cc: David Drysdale 
Signed-off-by: Richard Weinberger 
Acked-by: Kees Cook

um: Rework uaccess code

2015-05-31T15:32:36+00:00

Rework UML's uaccess code to reuse as much as possible
from asm-generic/uaccess.c.

Signed-off-by: Richard Weinberger

um: Remove signal translation and exec_domain

2015-04-12T19:03:28+00:00

As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.

Signed-off-by: Richard Weinberger

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12+00:00

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski 
Cc: Thomas Gleixner 
Cc: Al Viro 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: David Miller 
Acked-by: Richard Weinberger 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Steven Miao 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Richard Kuo 
Cc: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Michael Ellerman  (powerpc)
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Oleg Nesterov 
Cc: Guenter Roeck 
Signed-off-by: James Hogan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds