linux.git/arch/powerpc/include/asm/thread_info.h, branch v6.7 Linux kernel source tree Revert "powerpc/64s: Remove support for ELFv1 little endian userspace" 2023-07-19T11:28:35+00:00 Andrew Donnellan ajd@linux.ibm.com 2023-07-19T07:18:21+00:00 106ea7ffd56b0f9454cd4f625474967f12ac4dbd This reverts commit 606787fed7268feb256957872586370b56af697a. ELFv1 with LE has never been a thing, and people who try to make ELFv1 LE binaries are maniacs who need to be stopped, but unfortunately there are ELFv1 LE binaries out there in the wild. One such binary is the ppc64el (as Debian calls it) helper for arch-test[0], a tool for detecting architectures that can be executed on a given machine by means of attempting to execute helper binaries compiled for each architecture and seeing which binaries succeed and fail. The helpers are small snippets of assembly, and the ppc64el assembly doesn't include the right directives to generate an ELFv2 binary. This results in arch-test incorrectly determining that a ppc64el kernel can't execute a ppc64el userspace, which in turn means that a number of developer tools such as debootstrap will break (assuming arch-test is installed). [0] https://github.com/kilobyte/arch-test Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230719071821.320594-1-ajd@linux.ibm.com 
This reverts commit 606787fed7268feb256957872586370b56af697a.

ELFv1 with LE has never been a thing, and people who try to make ELFv1 LE
binaries are maniacs who need to be stopped, but unfortunately there are
ELFv1 LE binaries out there in the wild.

One such binary is the ppc64el (as Debian calls it) helper for
arch-test[0], a tool for detecting architectures that can be executed on a
given machine by means of attempting to execute helper binaries compiled
for each architecture and seeing which binaries succeed and fail. The
helpers are small snippets of assembly, and the ppc64el assembly doesn't
include the right directives to generate an ELFv2 binary.

This results in arch-test incorrectly determining that a ppc64el kernel
can't execute a ppc64el userspace, which in turn means that a number of
developer tools such as debootstrap will break (assuming arch-test is
installed).

[0] https://github.com/kilobyte/arch-test

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230719071821.320594-1-ajd@linux.ibm.com
powerpc/64s: Remove support for ELFv1 little endian userspace 2023-06-14T02:46:42+00:00 Nicholas Piggin npiggin@gmail.com 2023-06-06T09:38:32+00:00 606787fed7268feb256957872586370b56af697a ELFv2 was introduced together with little-endian. ELFv1 with LE has never been a thing. The GNU toolchain can create such a beast, but anyone doing that is a maniac who needs to be stopped so I consider this patch a feature. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230606093832.199712-5-npiggin@gmail.com 
ELFv2 was introduced together with little-endian. ELFv1 with LE has
never been a thing. The GNU toolchain can create such a beast, but
anyone doing that is a maniac who needs to be stopped so I consider
this patch a feature.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230606093832.199712-5-npiggin@gmail.com
powerpc: copy_thread differentiate kthreads and user mode threads 2023-04-11T13:13:33+00:00 Nicholas Piggin npiggin@gmail.com 2023-03-25T12:29:01+00:00 eed7c420aac7fde5e5915d2747c3ebbbda225835 When copy_thread is given a kernel function to run in arg->fn, this does not necessarily mean it is a kernel thread. User threads can be created this way (e.g., kernel_init, see also x86's copy_thread()). These threads run a kernel function which may call kernel_execve() and return, which returns like a userspace exec(2) syscall. Kernel threads are to be differentiated with PF_KTHREAD, will always have arg->fn set, and should never return from that function, instead calling kthread_exit() to exit. Create separate paths for the kthread and user kernel thread creation logic. The kthread path will never exit and does not require a user interrupt frame, so it gets a minimal stack frame. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230325122904.2375060-6-npiggin@gmail.com 
When copy_thread is given a kernel function to run in arg->fn, this
does not necessarily mean it is a kernel thread. User threads can be
created this way (e.g., kernel_init, see also x86's copy_thread()).
These threads run a kernel function which may call kernel_execve()
and return, which returns like a userspace exec(2) syscall.

Kernel threads are to  be differentiated with PF_KTHREAD, will always
have arg->fn set, and should never return from that function, instead
calling kthread_exit() to exit.

Create separate paths for the kthread and user kernel thread creation
logic. The kthread path will never exit and does not require a user
interrupt frame, so it gets a minimal stack frame.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-6-npiggin@gmail.com
powerpc: Implement arch_within_stack_frames 2023-04-04T12:11:03+00:00 Nicholas Miehlbradt nicholas@linux.ibm.com 2023-02-28T05:43:55+00:00 ac9c8901cb10aab043bf3599d19eebacfcda2858 Walks the stack when copy_{to,from}_user address is in the stack to ensure that the object being copied is entirely a single stack frame and does not contain stack metadata. Substantially similar to the x86 implementation. The back chain is used to traverse the stack and identify stack frame boundaries. Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230228054355.300628-1-nicholas@linux.ibm.com 
Walks the stack when copy_{to,from}_user address is in the stack to
ensure that the object being copied is entirely a single stack frame and
does not contain stack metadata.

Substantially similar to the x86 implementation. The back chain is used
to traverse the stack and identify stack frame boundaries.

Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230228054355.300628-1-nicholas@linux.ibm.com
powerpc/kasan: Force thread size increase with KASAN 2022-06-02T12:56:47+00:00 Michael Ellerman mpe@ellerman.id.au 2022-06-01T14:31:14+00:00 3e8635fb2e072672cbc650989ffedf8300ad67fb KASAN causes increased stack usage, which can lead to stack overflows. The logic in Kconfig to suggest a larger default doesn't work if a user has CONFIG_EXPERT enabled and has an existing .config with a smaller value. Follow the lead of x86 and arm64, and force the thread size to be increased when KASAN is enabled. That also has the effect of enlarging the stack for 64-bit KASAN builds, which is also desirable. Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT") Reported-by: Erhard Furtner <erhard_f@mailbox.org> Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Use MIN_THREAD_SHIFT as suggested by Christophe] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au 
KASAN causes increased stack usage, which can lead to stack overflows.

The logic in Kconfig to suggest a larger default doesn't work if a user
has CONFIG_EXPERT enabled and has an existing .config with a smaller
value.

Follow the lead of x86 and arm64, and force the thread size to be
increased when KASAN is enabled.

That also has the effect of enlarging the stack for 64-bit KASAN builds,
which is also desirable.

Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT")
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Use MIN_THREAD_SHIFT as suggested by Christophe]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au
powerpc/ftrace: Add support for livepatch to PPC32 2022-02-07T10:03:10+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-12-20T16:38:12+00:00 a4520b25276500f1abcfc55d24f1251b7b08eff6 PPC64 needs some special logic to properly set up the TOC. See commit 85baa095497f ("powerpc/livepatch: Add live patching support on ppc64le") for details. PPC32 doesn't have TOC so it doesn't need that logic, so adding LIVEPATCH support is straight forward. Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item. Livepatch sample modules all work. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/63cb094125b6a6038c65eeac2abaabbabe63addd.1640017960.git.christophe.leroy@csgroup.eu 
PPC64 needs some special logic to properly set up the TOC.
See commit 85baa095497f ("powerpc/livepatch: Add live patching support
on ppc64le") for details.

PPC32 doesn't have TOC so it doesn't need that logic, so adding
LIVEPATCH support is straight forward.

Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item.

Livepatch sample modules all work.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/63cb094125b6a6038c65eeac2abaabbabe63addd.1640017960.git.christophe.leroy@csgroup.eu
powerpc/audit: Fix syscall_get_arch() 2022-01-15T01:21:26+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2022-01-14T11:26:25+00:00 252745240ba0ae774d2f80c5e185ed59fbc4fb41 Commit 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") and commit 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task(). But is_32bit_task() applies on current task while be want the test done on task 'task' So add a new macro is_tsk_32bit_task() to check any task. Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") Cc: stable@vger.kernel.org Reported-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c55cddb8f65713bf5859ed675d75a50cb37d5995.1642159570.git.christophe.leroy@csgroup.eu 
Commit 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
and commit 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef
in syscall_get_arguments()")
replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task().

But is_32bit_task() applies on current task while be want the test
done on task 'task'

So add a new macro is_tsk_32bit_task() to check any task.

Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()")
Cc: stable@vger.kernel.org
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c55cddb8f65713bf5859ed675d75a50cb37d5995.1642159570.git.christophe.leroy@csgroup.eu
powerpc: add CPU field to struct thread_info 2021-09-30T14:13:10+00:00 Ard Biesheuvel ardb@kernel.org 2021-09-14T12:10:32+00:00 227d735d889e0403f1659df6e2dece7633f380bc The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to powerpc's definition of struct thread_info. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> 
The CPU field will be moved back into thread_info even when
THREAD_INFO_IN_TASK is enabled, so add it back to powerpc's definition
of struct thread_info.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64s: power4 nap fixup in C 2021-04-08T11:17:45+00:00 Nicholas Piggin npiggin@gmail.com 2021-04-06T02:55:08+00:00 98db179a78dd8379e9d2cbfc3f00224168a9344c There is no need for this to be in asm, use the new intrrupt entry wrapper. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com 
There is no need for this to be in asm, use the new intrrupt entry wrapper.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210406025508.821718-1-npiggin@gmail.com
powerpc: Remove duplicate includes 2021-03-24T03:09:30+00:00 Zhang Yunkai zhang.yunkai@zte.com.cn 2021-03-04T04:49:43+00:00 1a0e4550fb12d51cd76e2b9439f45977473b022f asm/tm.h included in traps.c is duplicated. It is also included on the 62nd line. asm/udbg.h included in setup-common.c is duplicated. It is also included on the 61st line. asm/bug.h included in arch/powerpc/include/asm/book3s/64/mmu-hash.h is duplicated. It is also included on the 12th line. asm/tlbflush.h included in arch/powerpc/include/asm/pgtable.h is duplicated. It is also included on the 11th line. asm/page.h included in arch/powerpc/include/asm/thread_info.h is duplicated. It is also included on the 13th line. Signed-off-by: Zhang Yunkai <zhang.yunkai@zte.com.cn> [mpe: Squash together from multiple commits] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
asm/tm.h included in traps.c is duplicated. It is also included on
the 62nd line.

asm/udbg.h included in setup-common.c is duplicated. It is also
included on the 61st line.

asm/bug.h included in arch/powerpc/include/asm/book3s/64/mmu-hash.h
is duplicated. It is also included on the 12th line.

asm/tlbflush.h included in arch/powerpc/include/asm/pgtable.h is
duplicated. It is also included on the 11th line.

asm/page.h included in arch/powerpc/include/asm/thread_info.h is
duplicated. It is also included on the 13th line.

Signed-off-by: Zhang Yunkai <zhang.yunkai@zte.com.cn>
[mpe: Squash together from multiple commits]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>