Pull LoongArch updates from Huacai Chen:
- Better backtraces for humanization
- Relay BCE exceptions to userland as SIGSEGV
- Provide kernel fpu functions
- Optimize memory ops (memset/memcpy/memmove)
- Optimize checksum and crc32(c) calculation
- Add ARCH_HAS_FORTIFY_SOURCE selection
- Add function error injection support
- Add ftrace with direct call support
- Add basic perf tools support
* tag 'loongarch-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (24 commits)
tools/perf: Add basic support for LoongArch
LoongArch: ftrace: Add direct call trampoline samples support
LoongArch: ftrace: Add direct call support
LoongArch: ftrace: Implement ftrace_find_callable_addr() to simplify code
LoongArch: ftrace: Fix build error if DYNAMIC_FTRACE_WITH_REGS is not set
LoongArch: ftrace: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses
LoongArch: Add support for function error injection
LoongArch: Add ARCH_HAS_FORTIFY_SOURCE selection
LoongArch: crypto: Add crc32 and crc32c hw acceleration
LoongArch: Add checksum optimization for 64-bit system
LoongArch: Optimize memory ops (memset/memcpy/memmove)
LoongArch: Provide kernel fpu functions
LoongArch: Relay BCE exceptions to userland as SIGSEGV with si_code=SEGV_BNDERR
LoongArch: Tweak the BADV and CPUCFG.PRID lines in show_regs()
LoongArch: Humanize the ESTAT line when showing registers
LoongArch: Humanize the ECFG line when showing registers
LoongArch: Humanize the EUEN line when showing registers
LoongArch: Humanize the PRMD line when showing registers
LoongArch: Humanize the CRMD line when showing registers
LoongArch: Fix format of CSR lines during show_regs()
...
Select the HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the
register_ftrace_direct[_multi] interfaces allowing users to register
the customed trampoline (direct_caller) as the mcount for one or more
target functions. And modify_ftrace_direct[_multi] are also provided
for modifying direct_caller.
There are a few cases to distinguish:
- If a direct call ops is the only one tracing a function AND the direct
called trampoline is within the reach of a 'bl' instruction
-> the ftrace patchsite jumps to the trampoline
- Else
-> the ftrace patchsite jumps to the ftrace_regs_caller trampoline points
to ftrace_list_ops so it iterates over all registered ftrace ops,
including the direct call ops and calls its call_direct_funcs handler
which stores the direct called trampoline's address in the ftrace_regs
and the ftrace_regs_caller trampoline will return to that address
instead of returning to the traced function
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
In the module processing functions, the same logic can be reused by
implementing ftrace_find_callable_addr().
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
We can see the following build error if CONFIG_DYNAMIC_FTRACE_WITH_REGS
is not set on LoongArch:
arch/loongarch/kernel/ftrace_dyn.c: In function ‘ftrace_make_call’:
arch/loongarch/kernel/ftrace_dyn.c:167:23: error: implicit declaration of function ‘__get_mod’
167 | ret = __get_mod(&mod, pc);
| ^~~~~~~~~
arch/loongarch/kernel/ftrace_dyn.c:171:24: error: implicit declaration of function ‘get_plt_addr’
171 | addr = get_plt_addr(mod, addr);
| ^~~~~~~~~~~~
The reason is that the __get_mod() and get_plt_addr() may be called in
ftrace_make_{call,nop}.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Provide kernel_fpu_begin()/kernel_fpu_end() to allow the kernel itself
to use fpu. They can be used by some other kernel components, e.g., the
AMDGPU graphic driver for DCN.
Reported-by: WANG Xuerui <kernel@xen0n.name>
Tested-by: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
SEGV_BNDERR was introduced initially for supporting the Intel MPX, but
fell into disuse after the MPX support was removed. The LoongArch
bounds-checking instructions behave very differently than MPX, but
overall the interface is still kind of suitable for conveying the
information to userland when bounds-checking assertions trigger, so we
wouldn't have to invent more UAPI. Specifically, when the BCE triggers,
a SEGV_BNDERR is sent to userland, with si_addr set to the out-of-bounds
address or value (in asrt{gt,le}'s case), and one of si_lower or
si_upper set to the configured bound depending on the faulting
instruction. The other bound is set to either 0 or ULONG_MAX to resemble
a range with both lower and upper bounds.
Note that it is possible to have si_addr == si_lower in case of a
failing asrtgt or {ld,st}gt, because those instructions test for strict
greater-than relationship. This should not pose a problem for userland,
though, because the faulting PC is available for the application to
associate back to the exact instruction for figuring out the
expectation.
Example exception context generated by a faulting `asrtgt.d t0, t1`
(assert t0 > t1 or BCE) with t0=100 and t1=200:
> pc 00005555558206a4 ra 00007ffff2d854fc tp 00007ffff2f2f180 sp 00007ffffbf9fb80
> a0 0000000000000002 a1 00007ffffbf9fce8 a2 00007ffffbf9fd00 a3 00007ffff2ed4558
> a4 0000000000000000 a5 00007ffff2f044c8 a6 00007ffffbf9fce0 a7 fffffffffffff000
> t0 0000000000000064 t1 00000000000000c8 t2 00007ffffbfa2d5e t3 00007ffff2f12aa0
> t4 00007ffff2ed6158 t5 00007ffff2ed6158 t6 000000000000002e t7 0000000003d8f538
> t8 0000000000000005 u0 0000000000000000 s9 0000000000000000 s0 00007ffffbf9fce8
> s1 0000000000000002 s2 0000000000000000 s3 00007ffff2f2c038 s4 0000555555820610
> s5 00007ffff2ed5000 s6 0000555555827e38 s7 00007ffffbf9fd00 s8 0000555555827e38
> ra: 00007ffff2d854fc
> ERA: 00005555558206a4
> CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
> PRMD: 00000007 (PPLV3 +PIE -PWE)
> EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
> ECFG: 0007181c (LIE=2-4,11-12 VS=7)
> ESTAT: 000a0000 [BCE] (IS= ECode=10 EsubCode=0)
> PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use ISA manual names for BADV and CPUCFG.PRID lines in show_regs(), for
stylistic consistency with the other lines already touched.
While at it, also include current CPU's full name in show_regs() output.
It may be more helpful for developers looking at the resulting dumps,
because multiple distinct CPU models may share the same PRID. Not having
this info available may hide problems only found on some but not all of
the models sharing one specific PRID.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Example output looks like:
[ xx.xxxxxx] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
Some initial machinery for this pretty-printing format has been included
in this patch as well.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use uppercase CSR names throughout for consistency with the manual
wording, and right-align the keys. The "CSR" part is inferrable from
context, hence dropped for more horizontal space.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Otherwise the addresses wouldn't make sense at all.
While at it, align the "map keys" to maintain right-alignment with the
"estat:" line too; also swap the ERA and ra lines so all CSRs are shown
together.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Show PC (CSR.ERA) in place of $zero, and also show the syscall restart
flag (conveniently stuffed in regs[0]) if non-zero.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
While interrupts are assigned ECodes `64 + interrupt number`, all
existing use sites of interrupt numbers want the 64 subtracted.
Re-arrange the definitions so that the actual interrupt number is used
everywhere, and make EXCCODE_INT_END inclusive as it is more intuitive
that way.
While at it, according to the asm/loongarch.h definitions, the total
number of architectural interrupts should be 14, but various other
places indicate otherwise (13 or 15). Those places have been adjusted
to 14 as well for consistency.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
Pull objtool updates from Ingo Molnar:
- Mark arch_cpu_idle_dead() __noreturn, make all architectures &
drivers that did this inconsistently follow this new, common
convention, and fix all the fallout that objtool can now detect
statically
- Fix/improve the ORC unwinder becoming unreliable due to
UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK
and UNWIND_HINT_UNDEFINED to resolve it
- Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code
- Generate ORC data for __pfx code
- Add more __noreturn annotations to various kernel startup/shutdown
and panic functions
- Misc improvements & fixes
* tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
x86/hyperv: Mark hv_ghcb_terminate() as noreturn
scsi: message: fusion: Mark mpt_halt_firmware() __noreturn
x86/cpu: Mark {hlt,resume}_play_dead() __noreturn
btrfs: Mark btrfs_assertfail() __noreturn
objtool: Include weak functions in global_noreturns check
cpu: Mark nmi_panic_self_stop() __noreturn
cpu: Mark panic_smp_self_stop() __noreturn
arm64/cpu: Mark cpu_park_loop() and friends __noreturn
x86/head: Mark *_start_kernel() __noreturn
init: Mark start_kernel() __noreturn
init: Mark [arch_call_]rest_init() __noreturn
objtool: Generate ORC data for __pfx code
x86/linkage: Fix padding for typed functions
objtool: Separate prefix code from stack validation code
objtool: Remove superfluous dead_end_function() check
objtool: Add symbol iteration helpers
objtool: Add WARN_INSN()
scripts/objdump-func: Support multiple functions
context_tracking: Fix KCSAN noinstr violation
objtool: Add stackleak instrumentation to uaccess safe list
...
After commit c78c43fe7d ("LoongArch: Use acpi_arch_dma_setup() and
remove ARCH_HAS_PHYS_TO_DMA"), plat_swiotlb_setup() has been deleted,
so clean up the related code.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
We can see the following messages with CONFIG_PROVE_LOCKING=y on
LoongArch:
BUG: MAX_STACK_TRACE_ENTRIES too low!
turning off the locking correctness validator.
This is because stack_trace_save() returns a big value after call
arch_stack_walk(), here is the call trace:
save_trace()
stack_trace_save()
arch_stack_walk()
stack_trace_consume_entry()
arch_stack_walk() should return immediately if unwind_next_frame()
failed, no need to do the useless loops to increase the value of c->len
in stack_trace_consume_entry(), then we can fix the above problem.
Cc: stable@vger.kernel.org
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/8a44ad71-68d2-4926-892f-72bfc7a67e2a@roeck-us.net/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This is done in order to easily calculate the number of breakpoints in
hw_break_get()/hw_break_set().
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
vm_map_base, empty_zero_page and invalid_pmd_table could be accessed
widely by some out-of-tree non-GPL but important file systems or drivers
(e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL()
to export them, so as to avoid build errors.
1, Details about vm_map_base:
This is a LoongArch-specific symbol and may be referenced through macros
PCI_IOBASE, VMALLOC_START and VMALLOC_END.
2, Details about empty_zero_page:
As it stands today, only 3 architectures export empty_zero_page as a GPL
symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by
inheriting from MIPS, and the MIPS export was first introduced in commit
497d2adcbf ("[MIPS] Export empty_zero_page for sake of the ext4
module."). The IA64 export was similar: commit a7d57ecf42 ("[IA64]
Export three symbols for module use") did so for kvm.
In both IA64 and MIPS, the export of empty_zero_page was done for
satisfying some in-kernel component built as module (kvm and ext4
respectively), and given its reasonably low-level nature, GPL is a
reasonable choice. But looking at the bigger picture it is evident most
other architectures do not regard it as GPL, so in effect the symbol
probably should not be treated as such, in favor of consistency.
3, Details about invalid_pmd_table:
Keep consistency with invalid_pte_table and make it be possible by some
modules.
Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Not all LoongArch processors support CRC32 instructions. This feature
is indicated by CPUCFG1.CRC32 (Bit25) but it is wrongly defined in the
previous versions of the ISA manual (and so does in loongarch.h). The
CRC32 feature is set unconditionally now, so fix it.
BTW, expose the CRC32 feature in /proc/cpuinfo.
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
LoongArch maintains cache coherency in hardware, but when paired with
LS7A chipsets the WUC attribute (Weak-ordered UnCached, which is similar
to WriteCombine) is out of the scope of cache coherency machanism for
PCIe devices (this is a PCIe protocol violation, which may be fixed in
newer chipsets).
This means WUC can only used for write-only memory regions now, so this
option is disabled by default, making WUC silently fallback to SUC for
ioremap(). You can enable this option if the kernel is ensured to run on
hardware without this bug.
Kernel parameter writecombine=on/off can be used to override the Kconfig
option.
Cc: stable@vger.kernel.org
Suggested-by: WANG Xuerui <kernel@xen0n.name>
Reviewed-by: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
To be able to trace invocations of smp_send_reschedule(), rename the
arch-specific definitions of it to arch_smp_send_reschedule() and wrap it
into an smp_send_reschedule() that contains a tracepoint.
Changes to include the declaration of the tracepoint were driven by the
following coccinelle script:
@func_use@
@@
smp_send_reschedule(...);
@include@
@@
#include <trace/events/ipi.h>
@no_include depends on func_use && !include@
@@
#include <...>
+
+ #include <trace/events/ipi.h>
[csky bits]
[riscv bits]
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead()
return"), in Xen, when a previously offlined CPU was brought back
online, it unexpectedly resumed execution where it left off in the
middle of the idle loop.
There were some hacks to make that work, but the behavior was surprising
as do_idle() doesn't expect an offlined CPU to return from the dead (in
arch_cpu_idle_dead()).
Now that Xen has been fixed, and the arch-specific implementations of
arch_cpu_idle_dead() also don't return, give it a __noreturn attribute.
This will cause the compiler to complain if an arch-specific
implementation might return. It also improves code generation for both
caller and callee.
Also fixes the following warning:
vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Pull LoongArch updates from Huacai Chen:
- Make -mstrict-align configurable
- Add kernel relocation and KASLR support
- Add single kernel image implementation for kdump
- Add hardware breakpoints/watchpoints support
- Add kprobes/kretprobes/kprobes_on_ftrace support
- Add LoongArch support for some selftests.
* tag 'loongarch-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (23 commits)
selftests/ftrace: Add LoongArch kprobe args string tests support
selftests/seccomp: Add LoongArch selftesting support
tools: Add LoongArch build infrastructure
samples/kprobes: Add LoongArch support
LoongArch: Mark some assembler symbols as non-kprobe-able
LoongArch: Add kprobes on ftrace support
LoongArch: Add kretprobes support
LoongArch: Add kprobes support
LoongArch: Simulate branch and PC* instructions
LoongArch: ptrace: Add hardware single step support
LoongArch: ptrace: Add function argument access API
LoongArch: ptrace: Expose hardware breakpoints to debuggers
LoongArch: Add hardware breakpoints/watchpoints support
LoongArch: kdump: Add crashkernel=YM handling
LoongArch: kdump: Add single kernel image implementation
LoongArch: Add support for kernel address space layout randomization (KASLR)
LoongArch: Add support for kernel relocation
LoongArch: Add la_abs macro implementation
LoongArch: Add JUMP_VIRT_ADDR macro implementation to avoid using la.abs
LoongArch: Use la.pcrel instead of la.abs when it's trivially possible
...
Kprobes allows you to trap at almost any kernel address and execute a
callback function, this commit adds kprobes support for LoongArch.
Tested-by: Jeff Xie <xiehuan09@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP handling. This implies defining
arch_has_single_step() and implementing the user_enable_single_step()
and user_disable_single_step() functions.
LoongArch cannot do hardware single-stepping per se, the hardware
single-stepping it is achieved by configuring the instruction fetch
watchpoints (FWPS) and specifies that the next instruction must trigger
the watch exception by setting the mask bit. In some scenarios
CSR.FWPS.Skip is used to ignore the next hit result, avoid endless
repeated triggering of the same watchpoint without canceling it.
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Implement the regset-based ptrace interface that exposes hardware
breakpoints to user-space debuggers to query and set instruction and
data breakpoints.
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use perf framework to manage hardware instruction and data breakpoints.
LoongArch defines hardware watchpoint functions for instruction fetch
and memory load/store operations. After the software configures hardware
watchpoints, the processor hardware will monitor the access address of
the instruction fetch and load/store operation, and trigger an exception
of the watchpoint when it meets the conditions set by the watchpoint.
The hardware monitoring points for instruction fetching and load/store
operations each have a register for the overall configuration of all
monitoring points, a register for recording the status of all monitoring
points, and four registers required for configuration of each watchpoint
individually.
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
When the kernel crashkernel parameter is specified with just a size,
we are supposed to allocate a region from RAM to store the crashkernel,
"crashkernel=512M" would be recommended for kdump.
Fix this by lifting similar code from x86, importing it to LoongArch
with LoongArch specific parameters added. We allocate the crashkernel
region from the first 4GB of physical memory (because SWIOTLB should be
allocated below 4GB). However, LoongArch currently does not implement
crashkernel_low and crashkernel_high the same as x86.
When X is not specified, crash_base defaults to 0 (crashkernel=YM@XM).
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This feature depends on the kernel being relocatable.
Enable using single kernel image for kdump, and then no longer need to
build two kernels (production kernel and capture kernel share a single
kernel image).
Also enable CONFIG_CRASH_DUMP in loongson3_defconfig.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This patch adds support for relocating the kernel to a random address.
Entropy is derived from the banner, which will change every build and
random_get_entropy() which should provide additional runtime entropy.
The kernel is relocated by up to RANDOMIZE_BASE_MAX_OFFSET bytes from
its link address. Because relocation happens so early during the kernel
booting, the amount of physical memory has not yet been determined. This
means the only way to limit relocation within the available memory is
via Kconfig. So we limit the maximum value of RANDOMIZE_BASE_MAX_OFFSET
to 256M (0x10000000) because our memory layout has many holes.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Xi Ruoyao <xry111@xry111.site> # Fix compiler warnings
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This config allows to compile kernel as PIE and to relocate it at any
virtual address at runtime: this paves the way to KASLR.
Runtime relocation is possible since relocation metadata are embedded
into the kernel.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Xi Ruoyao <xry111@xry111.site> # Use arch_initcall
Signed-off-by: Jinyang He <hejinyang@loongson.cn> # Provide la_abs relocation code
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use the "la_abs macro" instead of the "la.abs pseudo instruction" to
prepare for the subsequent PIE kernel. When PIE is not enabled, la_abs
is equivalent to la.abs.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add JUMP_VIRT_ADDR macro implementation to avoid using la.abs directly.
This is a preparation for subsequent patches.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Let's start to kill la.abs in preparation for the subsequent support of
the PIE kernel.
BTW, Re-tab the indention in arch/loongarch/kernel/entry.S for alignment.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Introduce Kconfig option ARCH_STRICT_ALIGN to make -mstrict-align be
configurable.
Not all LoongArch cores support h/w unaligned access, we can use the
-mstrict-align build parameter to prevent unaligned accesses.
CPUs with h/w unaligned access support:
Loongson-2K2000/2K3000/3A5000/3C5000/3D5000.
CPUs without h/w unaligned access support:
Loongson-2K500/2K1000.
This option is enabled by default to make the kernel be able to run on
all LoongArch systems. But you can disable it manually if you want to
run kernel only on systems with h/w unaligned access support in order to
optimise for performance.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
When exception is triggered, code flow go handle_\exception in some
cases. One of stackframe in this case as follows,
high -> +-------+
| REGS | <- a pt_regs
| |
| | <- ex trigger
| REGS | <- ex pt_regs <-+
| | |
| | |
low -> +-------+ ->unwind-+
When unwinder unwinds to handler_\exception it cannot go on prologue
analysis. Because it is an asynchronous code flow, we should get the
next frame PC from regs->csr_era rather than regs->regs[1]. At init time
we copy the handlers to eentry and also copy them to NUMA-affine memory
named pcpu_handlers if NUMA is enabled. Thus, unwinder cannot unwind
normally. To solve this, we try to give some hints in handler_\exception
and fixup unwinders in unwind_next_frame().
Reported-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The prolugue unwinder rely on symbol info. When PC is not in kernel text
address, it cannot find relative symbol info and it will be broken. The
guess unwinder will be used in this case. And the guess unwinder code in
prolugue unwinder is redundant. Strip it out and set the unwinder type
in unwind_state. Make guess_unwinder::unwind_next_frame() as default way
when other unwinders cannot unwind in some extreme case.
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The stack frame when function_graph enable like follows,
--------- <- function sp_on_entry
|
|
|
FAKE_RA <- sp_on_entry - sizeof(pt_regs) + PT_R1
|
--------- <- sp_on_entry - sizeof(pt_regs)
So if we want to get the &FAKE_RA we should get sp_on_entry first. In
the unwinder_prologue case, we can get the sp_on_entry as state->sp,
because we try to calculate each CFA and the ra saved address. But in
the unwinder_guess case, we cannot get it because we do not try to
calculate the CFA. Although LoongArch have not fixed frame, the $ra is
saved at CFA - 8 in most cases, we can try guess, too. As we store the
pc in state, we not need to dereference state->sp, too.
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
