linux-stable.git/arch/mips/kernel/asm-offsets.c, branch linux-rolling-stable

arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c

2025-11-02T13:18:04+00:00

[ Upstream commit 35561bab768977c9e05f1f1a9bc00134c85f3e28 ]

The include/generated/asm-offsets.h is generated in Kbuild during
compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to
generate another similar offset header file, circular dependency can
happen.

For example, we want to generate a offset file include/generated/test.h,
which is included in include/sched/sched.h. If we generate asm-offsets.h
first, it will fail, as include/sched/sched.h is included in asm-offsets.c
and include/generated/test.h doesn't exist; If we generate test.h first,
it can't success neither, as include/generated/asm-offsets.h is included
by it.

In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular
dependency. We can generate asm-offsets.h first, and if the
COMPILE_OFFSETS is defined, we don't include the "generated/test.h".

And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this
purpose.

Signed-off-by: Menglong Dong 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Sasha Levin

MIPS: CPS: Introduce struct cluster_boot_config

2025-02-21T09:19:34+00:00

In preparation for supporting multi-cluster systems, introduce a struct
cluster_boot_config as an extra layer in the boot configuration
maintained by the MIPS Coherent Processing System (CPS) SMP
implementation. For now only one struct cluster_boot_config will be
allocated & we'll simply defererence its core_config field to find the
struct core_boot_config array which can be used to boot as usual.

Signed-off-by: Paul Burton 
Signed-off-by: Dragan Mladjenovic 
Signed-off-by: Aleksandar Rikalo 
Tested-by: Serge Semin 
Tested-by: Gregory CLEMENT 
Signed-off-by: Thomas Bogendoerfer

MIPS: Export syscall stack arguments properly for remote use

2025-02-13T11:41:18+00:00

We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument #4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument #3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument #2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument #1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument #8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument #7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument #6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument #5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki 
Signed-off-by: Thomas Bogendoerfer

MIPS: scall: Save thread_info.syscall unconditionally on entry

2024-04-09T14:52:21+00:00

thread_info.syscall is used by syscall_get_nr to supply syscall nr
over a thread stack frame.

Previously, thread_info.syscall is only saved at syscall_trace_enter
when syscall tracing is enabled. However rest of the kernel code do
expect syscall_get_nr to be available without syscall tracing. The
previous design breaks collect_syscall.

Move saving process to syscall entry to fix it.

Reported-by: Xi Ruoyao 
Link: https://github.com/util-linux/util-linux/issues/2867
Signed-off-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer

mips: asm-offsets: add missing prototypes

2023-06-09T08:18:42+00:00

Building with -Werror and W=1 fails entirely because of warnings in
asm-offsets.c:

arch/mips/kernel/asm-offsets.c:26:6: error: no previous prototype for 'output_ptreg_defines' [-Werror=missing-prototypes]
arch/mips/kernel/asm-offsets.c:78:6: error: no previous prototype for 'output_task_defines' [-Werror=missing-prototypes]
arch/mips/kernel/asm-offsets.c:92:6: error: no previous prototype for 'output_thread_info_defines' [-Werror=missing-prototypes]
arch/mips/kernel/asm-offsets.c:108:6: error: no previous prototype for 'output_thread_defines' [-Werror=missing-prototypes]
arch/mips/kernel/asm-offsets.c:136:6: error: no previous prototype for 'output_thread_fpu_defines' [-Werror=missing-prototypes]

Nothing actually calls these functions, so just add prototypes to shut
up the warnings.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thomas Bogendoerfer

MIPS: Octeon: Allow CVMSEG to be disabled

2023-04-05T07:45:09+00:00

Don't include cvmseg states into thread_status when
CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE is not defined or 0.

Fix compile for kernel without this feature.

Signed-off-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer

mips: rename PGD_ORDER to PGD_TABLE_ORDER

2022-07-18T00:14:42+00:00

This is the order of the page table allocation, not the order of a PGD.

While at it remove unused defintion of _PGD_ORDER in asm-offsets.

Link: https://lkml.kernel.org/r/20220703141203.147893-7-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Cc: Arnd Bergmann 
Cc: Dinh Nguyen 
Cc: Guo Ren 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: James Bottomley 
Cc: "Matthew Wilcox (Oracle)" 
Cc: Max Filippov 
Cc: Thomas Bogendoerfer 
Cc: Xuerui Wang 
Signed-off-by: Andrew Morton

mips: drop definitions of PTE_ORDER

2022-07-18T00:14:42+00:00

This is the order of the page table allocation, not the order of a PTE. 
Since its always hardwired to 0, simply drop it.

Link: https://lkml.kernel.org/r/20220703141203.147893-6-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Cc: Arnd Bergmann 
Cc: Dinh Nguyen 
Cc: Guo Ren 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: James Bottomley 
Cc: "Matthew Wilcox (Oracle)" 
Cc: Max Filippov 
Cc: Thomas Bogendoerfer 
Cc: Xuerui Wang 
Signed-off-by: Andrew Morton

mips: rename PMD_ORDER to PMD_TABLE_ORDER

2022-07-18T00:14:42+00:00

This is the order of the page table allocation, not the order of a PMD.

While at it remove unused defintion of _PMD_ORDER in asm-offsets.

Link: https://lkml.kernel.org/r/20220703141203.147893-4-rppt@kernel.org
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Mike Rapoport 
Cc: Arnd Bergmann 
Cc: Dinh Nguyen 
Cc: Guo Ren 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: James Bottomley 
Cc: Max Filippov 
Cc: Thomas Bogendoerfer 
Cc: Xuerui Wang 
Signed-off-by: Andrew Morton

sched,arch: Remove unused TASK_STATE offsets

2021-06-18T09:43:09+00:00

All 6 architectures define TASK_STATE in asm-offsets, but then never
actually use it. Remove the definitions to make sure they never will.

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20210611082838.472811363@infradead.org