Commit Graph

9 Commits

Author SHA1 Message Date
Yao Zi
3ec09344b0 LoongArch: Fix bitflag conflict for TIF_FIXADE
After LoongArch was converted to use the generic TIF bits in commit
f9629891d4 ("loongarch: Use generic TIF bits"), its TIF_FIXADE flag
takes the same bit with TIF_RESTORE_SIGMASK in thread_info.flags.

Such conflict causes TIF_FIXADE being considered cleared when
TIF_RESTORE_SIGMASK is cleared during deliver of a signal. And since
TIF_FIXADE determines whether unaligned access emulation works for a
task, userspace making use of unaligned access will receive unexpected
SIGBUS (and likely terminate) after receiving its first signal.

This conflict looks like a simple typo, switch it to the free bit 19.

Fixes: f9629891d4 ("loongarch: Use generic TIF bits")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
2025-09-20 09:55:56 +02:00
Thomas Gleixner
f9629891d4 loongarch: Use generic TIF bits
No point in defining generic items and the upcoming RSEQ optimizations are
only available with this _and_ the generic entry infrastructure, which is
already used by loongarch. So no further action required here.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2025-09-17 08:14:04 +02:00
Thomas Huth
f0ef0b02af LoongArch: Replace __ASSEMBLY__ with __ASSEMBLER__ in headers
While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembler code, __ASSEMBLY__ is a macro
that only gets defined by the Makefiles in the kernel. This is bad
since macros starting with two underscores are names that are reserved
by the C language. It can also be very confusing for the developers
when switching between userspace and kernelspace coding, or when
dealing with uapi headers that rather should use __ASSEMBLER__ instead.
So let's now standardize on the __ASSEMBLER__ macro that is provided
by the compilers.

This is almost a completely mechanical patch (done with a simple
"sed -i" statement), with one comment tweaked manually in the
arch/loongarch/include/asm/cpu.h file (it was missing the trailing
underscores).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-06-26 20:07:10 +08:00
Huacai Chen
704f06eeff LoongArch: Allow to enable PREEMPT_LAZY
LoongArch has supported PREEMPT_RT now. It uses GENERIC_ENTRY, so just
add the TIF bit (TIF_NEED_RESCHED_LAZY) related definitions and select
the Kconfig symbol (ARCH_HAS_PREEMPT_LAZY) is enough to make it go.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-11-26 18:06:04 +08:00
Jinyang He
199cc14cb4 LoongArch: Add kernel livepatching support
The arch-specified function ftrace_regs_set_instruction_pointer() has
been implemented in arch/loongarch/include/asm/ftrace.h, so here only
implement arch_stack_walk_reliable() function.

Here are the test logs:

[root@linux fedora]# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3

[root@linux fedora]# modprobe livepatch-sample
[root@linux fedora]# cat /proc/cmdline
this has been live patched

[root@linux fedora]# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
[root@linux fedora]# rmmod livepatch_sample
[root@linux fedora]# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3

[root@linux fedora]# dmesg -t | tail -5
livepatch: enabling patch 'livepatch_sample'
livepatch: 'livepatch_sample': starting patching transition
livepatch: 'livepatch_sample': patching complete
livepatch: 'livepatch_sample': starting unpatching transition
livepatch: 'livepatch_sample': unpatching complete

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-03-11 22:23:47 +08:00
Qi Hu
bd3c579848 LoongArch: Add Loongson Binary Translation (LBT) extension support
Loongson Binary Translation (LBT) is used to accelerate binary translation,
which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags)
and x87 fpu stack pointer (ftop).

This patch support kernel to save/restore these registers, handle the LBT
exception and maintain sigcontext.

Signed-off-by: Qi Hu <huqi@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:53:55 +08:00
Huacai Chen
61a6fccc0b LoongArch: Add unaligned access support
Loongson-2 series (Loongson-2K500, Loongson-2K1000) don't support
unaligned access in hardware, while Loongson-3 series (Loongson-3A5000,
Loongson-3C5000) are configurable whether support unaligned access in
hardware. This patch add unaligned access emulation for those LoongArch
processors without hardware support.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14 08:36:11 +08:00
WANG Xuerui
d8e7f201a4 LoongArch: Use ABI names of registers where appropriate
Some of the assembly in the LoongArch port seem to come from a
prehistoric time, when the assembler didn't even have support for the
ABI names we all come to know and love, thus used raw register numbers
which hampered readability.

The usages are found with a regex match inside arch/loongarch, then
manually adjusted for those non-definitions.

Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29 18:22:32 +08:00
Huacai Chen
803b0fc5c3 LoongArch: Add process management
Add process management support for LoongArch, including: thread info
definition, context switch and process tracing.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03 20:09:28 +08:00