um: restore process name

After the execve() to disable ASLR, comm is now "exe",
which is a bit confusing. Use readlink() to get this
to the right name again.

Disable stack frame size warnings on ma

um: restore process name

After the execve() to disable ASLR, comm is now "exe",
which is a bit confusing. Use readlink() to get this
to the right name again.

Disable stack frame size warnings on main.o since it's
part of the initial userspace and can use larger stack.

Fixes: 68b9883cc16e ("um: Discover host_task_size from envp")
Link: https://patch.msgid.link/20241010161411.c576e2aeb3e5.I244d4f34b8a8555ee5bec0e1cf5027bce4cc491b@changeid
Signed-off-by: Johannes Berg <[email protected]>

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kbuild: remove --include-dir MAKEFLAG from top Makefile

I added $(srctree)/ to some included Makefiles in the following commits:

- 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefi

kbuild: remove --include-dir MAKEFLAG from top Makefile

I added $(srctree)/ to some included Makefiles in the following commits:

- 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles")
- d82856395505 ("kbuild: do not require sub-make for separate output tree builds")

They were a preparation for removing --include-dir flag.

I have never thought --include-dir useful. Rather, it _is_ harmful.

For example, run the following commands:

$ make -s ARCH=x86 mrproper defconfig
$ make ARCH=arm O=foo dtbs
make[1]: Entering directory '/tmp/linux/foo'
HOSTCC scripts/basic/fixdep
Error: kernelrelease not valid - run 'make prepare' to update it
UPD include/config/kernel.release
make[1]: Leaving directory '/tmp/linux/foo'

The first command configures the source tree for x86. The next command
tries to build ARM device trees in the separate foo/ directory - this
must stop because the directory foo/ has not been configured yet.

However, due to --include-dir=$(abs_srctree), the top Makefile includes
the wrong include/config/auto.conf from the source tree and continues
building. Kbuild traverses the directory tree, but of course it does
not work correctly. The Error message is also pointless - 'make prepare'
does not help at all for fixing the issue.

This commit fixes more arch Makefile, and finally removes --include-dir
from the top Makefile.

There are more breakages under drivers/, but I do not volunteer to fix
them all. I just moved --include-dir to drivers/Makefile.

With this commit, the second command will stop with a sensible message.

$ make -s ARCH=x86 mrproper defconfig
$ make ARCH=arm O=foo dtbs
make[1]: Entering directory '/tmp/linux/foo'
SYNC include/config/auto.conf.cmd
***
*** The source tree is not clean, please run 'make ARCH=arm mrproper'
*** in /tmp/linux
***
make[2]: *** [../Makefile:646: outputmakefile] Error 1
/tmp/linux/Makefile:770: include/config/auto.conf.cmd: No such file or directory
make[1]: *** [/tmp/linux/Makefile:793: include/config/auto.conf.cmd] Error 2
make[1]: Leaving directory '/tmp/linux/foo'
make: *** [Makefile:226: __sub-make] Error 2

Signed-off-by: Masahiro Yamada <[email protected]>

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um: Increase stack frame size threshold for signal.c

The signal.c can't use heap for bit data located on stack. However,
by default a compiler warns us about overstepping stack frame size
threshold:

um: Increase stack frame size threshold for signal.c

The signal.c can't use heap for bit data located on stack. However,
by default a compiler warns us about overstepping stack frame size
threshold:

arch/um/os-Linux/signal.c: In function ‘sig_handler_common’:
arch/um/os-Linux/signal.c:51:1: warning: the frame size of 2960 bytes is larger than 2048 bytes [-Wframe-larger-than=]
51 | }
| ^
arch/um/os-Linux/signal.c: In function ‘timer_real_alarm_handler’:
arch/um/os-Linux/signal.c:95:1: warning: the frame size of 2960 bytes is larger than 2048 bytes [-Wframe-larger-than=]
95 | }
| ^

Due to above increase stack frame size threshold explicitly for signal.c
to avoid unnecessary warning.

Signed-off-by: Andy Shevchenko <[email protected]>
Tested-by: David Gow <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

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um: Add SPDX headers for files in arch/um/os-Linux

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

Signed-off-by: Alex Dewar <[email protected]>
Signed-off-by: Richard

um: Add SPDX headers for files in arch/um/os-Linux

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

Signed-off-by: Alex Dewar <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

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um: remove unused AIO code

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

um: Support kcov

This adds support for kcov to UML.

There is a small problem where UML will randomly segfault during boot;
this is because current_thread_info() occasionally returns an invalid
(non

um: Support kcov

This adds support for kcov to UML.

There is a small problem where UML will randomly segfault during boot;
this is because current_thread_info() occasionally returns an invalid
(non-NULL) pointer and we try to dereference it in
__sanitizer_cov_trace_pc(). I consider this a bug in UML itself and this
patch merely exposes it.

[v2: disable instrumentation in UML-specific code]

Cc: Quentin Casasnovas <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Thomas Meyer <[email protected]>
Cc: user-mode-linux-devel <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Signed-off-by: Vegard Nossum <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

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um: use the right ifdef around exports in user_syms.c

... the same one that controls whether elf_aux.o is included into the
build, bringing the vsyscall_e... into it.

Signed-off-by: Al Viro <viro@z

um: use the right ifdef around exports in user_syms.c

... the same one that controls whether elf_aux.o is included into the
build, bringing the vsyscall_e... into it.

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

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um: merge os-Linux/tls.c into arch/x86/um/os-Linux/tls.c

it's i386-specific; moreover, analogs on other targets have
incompatible interface - PTRACE_GET_THREAD_AREA does exist
elsewhere, but struct

um: merge os-Linux/tls.c into arch/x86/um/os-Linux/tls.c

it's i386-specific; moreover, analogs on other targets have
incompatible interface - PTRACE_GET_THREAD_AREA does exist
elsewhere, but struct user_desc does *not*

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

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um: take arch/um/sys-x86 to arch/x86/um

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

um: merge arch/um/os-Linux/sys-{i386,x86_64}

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

um: kill dead code around uaccess

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>

um: disable scan_elf_aux() on x86_64

Reusing the host's vDSO makes only sense on x86_32.

Signed-off-by: Richard Weinberger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

um: disable scan_elf_aux() on x86_64

Reusing the host's vDSO makes only sense on x86_32.

Signed-off-by: Richard Weinberger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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uml: remove the dead TTY_LOG code

Remove the dead CONFIG_TTY_LOG (no kconfig option).

Reported-by: Robert P. J. Day <[email protected]>
Signed-off-by: Adrian Bunk <[email protected]>
Cc: Jeff Dik

uml: remove the dead TTY_LOG code

Remove the dead CONFIG_TTY_LOG (no kconfig option).

Reported-by: Robert P. J. Day <[email protected]>
Signed-off-by: Adrian Bunk <[email protected]>
Cc: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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uml: tidy kern_util.h

Tidy kern_util.h. It turns out that most of the function declarations
aren't used, so they can go away. os.h no longer includes
kern_util.h, so files which got it through os.

uml: tidy kern_util.h

Tidy kern_util.h. It turns out that most of the function declarations
aren't used, so they can go away. os.h no longer includes
kern_util.h, so files which got it through os.h now need to include it
directly. A number of other files never needed it, so these includes
are deleted.

The structure which was used to pass signal handlers from the kernel
side to the userspace side is gone. Instead, the handlers are
declared here, and used directly from libc code. This allows
arch/um/os-Linux/trap.c to be deleted, with its remnants being moved
to arch/um/os-Linux/skas/trap.c.

arch/um/os-Linux/tty.c had its inclusions changed, and it needed some
style attention, so it got tidied.

Signed-off-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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uml: style fixes pass 1

Formatting changes in the files which have been changed in the
tt-removal patchset so far. These include:
copyright updates
header file trimming
style fixes
adding sever

uml: style fixes pass 1

Formatting changes in the files which have been changed in the
tt-removal patchset so far. These include:
copyright updates
header file trimming
style fixes
adding severity to printks
indenting Kconfig help according to the predominant kernel style

These changes should be entirely non-functional.

Signed-off-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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uml: throw out CONFIG_MODE_TT

This patchset throws out tt mode, which has been non-functional for a while.

This is done in phases, interspersed with code cleanups on the affected files.

The remova

uml: throw out CONFIG_MODE_TT

This patchset throws out tt mode, which has been non-functional for a while.

This is done in phases, interspersed with code cleanups on the affected files.

The removal is done as follows:
remove all code, config options, and files which depend on
CONFIG_MODE_TT
get rid of the CHOOSE_MODE macro, which decided whether to
call tt-mode or skas-mode code, and replace invocations with their
skas portions
replace all now-trivial procedures with their skas equivalents

There are now a bunch of now-redundant pieces of data structures, including
mode-specific pieces of the thread structure, pt_regs, and mm_context. These
are all replaced with their skas-specific contents.

As part of the ongoing style compliance project, I made a style pass over all
files that were changed. There are three such patches, one for each phase,
covering the files affected by that phase but no later ones.

I noticed that we weren't freeing the LDT state associated with a process when
it exited, so that's fixed in one of the later patches.

The last patch is a tidying patch which I've had for a while, but which caused
inexplicable crashes under tt mode. Since that is no longer a problem, this
can now go in.

This patch:

Start getting rid of tt mode support.

This patch throws out CONFIG_MODE_TT and all config options, code, and files
which depend on it.

CONFIG_MODE_SKAS is gone and everything that depends on it is included
unconditionally.

The few changed lines are in re-written Kconfig help, lines which needed
something skas-related removed from them, and a few more which weren't
strictly deletions.

Signed-off-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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uml: stop saving process FP state

Throw out a lot of code dealing with saving and restoring floating-point
state. In skas mode, where processes run in a restoring floating-point state
on kernel ent

uml: stop saving process FP state

Throw out a lot of code dealing with saving and restoring floating-point
state. In skas mode, where processes run in a restoring floating-point state
on kernel entry and exit is pointless.

This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c. Most
of what remained is now arch-indpendent, and can be moved up to
arch/um/os-Linux/registers.c. Both arches need the jmp_buf accessor
get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during
sigreturn by getting the fp state using ptrace rather than copying it out of
the process sigcontext.

After this, it turns out that arch/um/include/skas/mode-skas.h is almost
completely unneeded. The declarations in it are variables which either don't
exist or which don't have global scope. The one exception is
kill_off_processes_skas. If that's removed, this header can be deleted.

This uncovered a bug in user.h, which wasn't correctly making sure that a
size_t definition was available to both userspace and kernelspace files.

Signed-off-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: make execvp safe for our usage

Reimplement execvp for our purposes - after we call fork() it is fundamentally
unsafe to use the kernel allocator - current is not valid there. So we sim

[PATCH] uml: make execvp safe for our usage

Reimplement execvp for our purposes - after we call fork() it is fundamentally
unsafe to use the kernel allocator - current is not valid there. So we simply
pass to our modified execvp() a preallocated buffer. This fixes a real bug
and works very well in testing (I've seen indirectly warning messages from the
forked thread - they went on the pipe connected to its stdout and where read
as a number by UML, when calling read_output(). I verified the obtained
number corresponded to "BUG:").

The added use of __cant_sleep() is not a new bug since __cant_sleep() is
already used in the same function - passing an atomicity parameter would be
better but it would require huge change, stating that this function must not
be called in atomic context and can sleep is a better idea (will make sure of
this gradually).

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Acked-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: mark some tt-mode code

Mark a symbol and file as being tt-mode only. This shrinks the binary
slightly when tt mode support is compiled out and makes it easier to identity
stuff when tt

[PATCH] uml: mark some tt-mode code

Mark a symbol and file as being tt-mode only. This shrinks the binary
slightly when tt mode support is compiled out and makes it easier to identity
stuff when tt mode is removed.

Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: implement {get,set}_thread_area for i386

Implement sys_[gs]et_thread_area and the corresponding ptrace operations for
UML. This is the main chunk, additional parts follow. This implem

[PATCH] uml: implement {get,set}_thread_area for i386

Implement sys_[gs]et_thread_area and the corresponding ptrace operations for
UML. This is the main chunk, additional parts follow. This implementation is
now well tested and has run reliably for some time, and we've understood all
the previously existing problems.

Their implementation saves the new GDT content and then forwards the call to
the host when appropriate, i.e. immediately when the target process is
running or on context switch otherwise (i.e. on fork and on ptrace() calls).

In SKAS mode, we must switch registers on each context switch (because SKAS
does not switches tls_array together with current->mm).

Also, added get_cpu() locking; this has been done for SKAS mode, since TT does
not need it (it does not use smp_processor_id()).

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Acked-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: remove unused make variables

Removed assignments to unused variables in arch/um/os-Linux/Makefile

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Jeff Dike <jdike@addto

[PATCH] uml: remove unused make variables

Removed assignments to unused variables in arch/um/os-Linux/Makefile

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: move tty logging to os-Linux

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from tty_log.c file under os-Linux dir

Signed-off-by: Gennady Sharap

[PATCH] uml: move tty logging to os-Linux

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from tty_log.c file under os-Linux dir

Signed-off-by: Gennady Sharapov <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: move sigio_user.c to os-Linux/sigio.c

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves sigio_user.c to os-Linux dir

Signed-off-by: Gennady Sharapov <Gennady.V.Sha

[PATCH] uml: move sigio_user.c to os-Linux/sigio.c

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves sigio_user.c to os-Linux dir

Signed-off-by: Gennady Sharapov <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: move libc-dependent irq code to os-Linux

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from irq_user.c file under os-Linux dir

Signed-off-by: G

[PATCH] uml: move libc-dependent irq code to os-Linux

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from irq_user.c file under os-Linux dir

Signed-off-by: Gennady Sharapov <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] uml: move libc-dependent utility procedures

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from user_util.c file under os-Linux dir

Signed-off-by: Ge

[PATCH] uml: move libc-dependent utility procedures

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from user_util.c file under os-Linux dir

Signed-off-by: Gennady Sharapov <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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