The maximum number of load/store watchpoints and fetch instruction
watchpoints is 14 each according to LoongArch Reference Manual, so
extend the maximum number of watchpoints from 8 to 14 for ptrace.
By the way, just simply change 8 to 14 for the definition in struct
user_watch_state at the beginning, but it may corrupt uapi, then add
a new struct user_watch_state_v2 directly.
As far as I can tell, the only users for this struct in the userspace
are GDB and LLDB, there are no any problems of software compatibility
between the application and kernel according to the analysis.
The compatibility problem has been considered while developing and
testing. When the applications in the userspace get watchpoint state,
the length will be specified which is no bigger than the sizeof struct
user_watch_state or user_watch_state_v2, the actual length is assigned
as the minimal value of the application and kernel in the generic code
of ptrace:
kernel/ptrace.c: ptrace_regset():
kiov->iov_len = min(kiov->iov_len,
(__kernel_size_t) (regset->n * regset->size));
if (req == PTRACE_GETREGSET)
return copy_regset_to_user(task, view, regset_no, 0,
kiov->iov_len, kiov->iov_base);
else
return copy_regset_from_user(task, view, regset_no, 0,
kiov->iov_len, kiov->iov_base);
For example, there are four kind of combinations, all of them work well.
(1) "older kernel + older gdb", the actual length is 8+(8+8+4+4)*8=200;
(2) "newer kernel + newer gdb", the actual length is 8+(8+8+4+4)*14=344;
(3) "older kernel + newer gdb", the actual length is 8+(8+8+4+4)*8=200;
(4) "newer kernel + older gdb", the actual length is 8+(8+8+4+4)*8=200.
Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints
Cc: stable@vger.kernel.org
Fixes: 1a69f7a161a7 ("LoongArch: ptrace: Expose hardware breakpoints to debuggers")
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The enable_gpe_wakeup() function calls acpi_enable_all_wakeup_gpes(),
and the later one may call the preempt_schedule_common() function,
resulting in a thread switch and causing the CPU to be in an interrupt
enabled state after the enable_gpe_wakeup() function returns, leading
to the warnings as follow.
[ C0] WARNING: ... at kernel/time/timekeeping.c:845 ktime_get+0xbc/0xc8
[ C0] ...
[ C0] Call Trace:
[ C0] [<90000000002243b4>] show_stack+0x64/0x188
[ C0] [<900000000164673c>] dump_stack_lvl+0x60/0x88
[ C0] [<90000000002687e4>] __warn+0x8c/0x148
[ C0] [<90000000015e9978>] report_bug+0x1c0/0x2b0
[ C0] [<90000000016478e4>] do_bp+0x204/0x3b8
[ C0] [<90000000025b1924>] exception_handlers+0x1924/0x10000
[ C0] [<9000000000343bbc>] ktime_get+0xbc/0xc8
[ C0] [<9000000000354c08>] tick_sched_timer+0x30/0xb0
[ C0] [<90000000003408e0>] __hrtimer_run_queues+0x160/0x378
[ C0] [<9000000000341f14>] hrtimer_interrupt+0x144/0x388
[ C0] [<9000000000228348>] constant_timer_interrupt+0x38/0x48
[ C0] [<90000000002feba4>] __handle_irq_event_percpu+0x64/0x1e8
[ C0] [<90000000002fed48>] handle_irq_event_percpu+0x20/0x80
[ C0] [<9000000000306b9c>] handle_percpu_irq+0x5c/0x98
[ C0] [<90000000002fd4a0>] generic_handle_domain_irq+0x30/0x48
[ C0] [<9000000000d0c7b0>] handle_cpu_irq+0x70/0xa8
[ C0] [<9000000001646b30>] handle_loongarch_irq+0x30/0x48
[ C0] [<9000000001646bc8>] do_vint+0x80/0xe0
[ C0] [<90000000002aea1c>] finish_task_switch.isra.0+0x8c/0x2a8
[ C0] [<900000000164e34c>] __schedule+0x314/0xa48
[ C0] [<900000000164ead8>] schedule+0x58/0xf0
[ C0] [<9000000000294a2c>] worker_thread+0x224/0x498
[ C0] [<900000000029d2f0>] kthread+0xf8/0x108
[ C0] [<9000000000221f28>] ret_from_kernel_thread+0xc/0xa4
[ C0]
[ C0] ---[ end trace 0000000000000000 ]---
The root cause is acpi_enable_all_wakeup_gpes() uses a mutex to protect
acpi_hw_enable_all_wakeup_gpes(), and acpi_ut_acquire_mutex() may cause
a thread switch. Since there is no longer concurrent execution during
loongarch_acpi_suspend(), we can call acpi_hw_enable_all_wakeup_gpes()
directly in enable_gpe_wakeup().
The solution is similar to commit 22db06337f590d01 ("ACPI: sleep: Avoid
breaking S3 wakeup due to might_sleep()").
Fixes: 366bb35a8e48 ("LoongArch: Add suspend (ACPI S3) support")
Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
SETUP_SLEEP should only save the GPR context, which is symmetric to
SETUP_WAKEUP, so move the acpi_saved_sp handling out of SETUP_SLEEP.
Move "addi.d sp, sp, PT_SIZE" into SETUP_WAKEUP for the same reason.
No functional changes.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
1. Early return for user mode triggered exception with all types.
2. Give a chance to call fixup_exception() for default types (like
S390).
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Commit cca98e9f8b5ebcd964 ("mm: enforce that vmap can't map pages
executable") enforces the W^X protection by not allowing remapping
existing pages as executable. Add LoongArch bits so that LoongArch
can benefit the same protection.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Correct the __switch_to() prototype in comments, keep it be the same as
the declaration in switch_to.h.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
As per arch spec, maximum timer bits is configurable and should not be
hardcoded in any way.
Probe timer bits from PRCFG1 and use that to determine the clockevent's
max_delta to be conformance.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When ARCH_IOREMAP is enabled, we are using always accessible DMW for
ioremap(). It makes no sense to create a dedicated mapping for earlycon
given that we can access the region via DMW.
Disable FIX_EARLYCON_MEM when ARCH_IOREMAP is selected. This can ease
debugging for early mapping issues.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
avecintc_init() enables the Advanced Interrupt Controller (AVEC) of
the boot CPU node, but nothing enables the AVEC on secondary nodes.
Move the enablement to the CPU hotplug callback so that secondary nodes get
the AVEC enabled too. In theory enabling it once per node would be
sufficient, but redundant enabling does no hurt, so keep the code simple
and do it unconditionally.
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/all/20250111023704.17285-1-zhangtianyang@loongson.cn
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Since commit 02fb4f008433 ("clk: clk-loongson2: Fix potential buffer
overflow in flexible-array member access"), the clk provider register is
failed.
The count of `clks_num` is shown below:
for (p = data; p->name; p++)
clks_num++;
In fact, `clks_num` represents the number of SoC clocks and should be
expressed as the maximum value of the clock binding id in use (p->id + 1).
Now we fix it to avoid the following error when trying to register a clk
provider:
[ 13.409595] of_clk_hw_onecell_get: invalid index 17
Cc: stable@vger.kernel.org
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Fixes: 02fb4f008433 ("clk: clk-loongson2: Fix potential buffer overflow in flexible-array member access")
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://lore.kernel.org/r/82e43d89a9a6791129cf8ea14f4eeb666cd87be4.1736856470.git.zhoubinbin@loongson.cn
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The TOY_MATCH0_REG should be cleared to 0 in the RTC interrupt handler,
otherwise the interrupt cannot be cleared, which will cause the
loongson_rtc_isr() to be triggered multiple times.
The previous code cleared TOY_MATCH0_REG in the loongson_rtc_handler(),
which is an ACPI interrupt. This did not prevent loongson_rtc_isr()
from being triggered multiple times.
This commit moves the clearing of TOY_MATCH0_REG to the
loongson_rtc_isr() to ensure that the interrupt is properly cleared.
Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips")
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Keguang Zhang <keguang.zhang@gmail.com> # on LS1B
Tested-by: Keguang Zhang <keguang.zhang@gmail.com>
Link: https://lore.kernel.org/r/20241205114307.1891418-1-wangming01@loongson.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Move the loongarch CRC32 assembly code into the lib directory and wire
it up to the library interface. This allows it to be used without going
through the crypto API. It remains usable via the crypto API too via
the shash algorithms that use the library interface. Thus all the
arch-specific "shash" code becomes unnecessary and is removed.
Note: to see the diff from arch/loongarch/crypto/crc32-loongarch.c to
arch/loongarch/lib/crc32-loongarch.c, view this commit with
'git show -M10'.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/20241202010844.144356-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Alexandre observed a warning emitted from pci_msi_setup_msi_irqs() on a
RISCV platform which does not provide PCI/MSI support:
WARNING: CPU: 1 PID: 1 at drivers/pci/msi/msi.h:121 pci_msi_setup_msi_irqs+0x2c/0x32
__pci_enable_msix_range+0x30c/0x596
pci_msi_setup_msi_irqs+0x2c/0x32
pci_alloc_irq_vectors_affinity+0xb8/0xe2
RISCV uses hierarchical interrupt domains and correctly does not implement
the legacy fallback. The warning triggers from the legacy fallback stub.
That warning is bogus as the PCI/MSI layer knows whether a PCI/MSI parent
domain is associated with the device or not. There is a check for MSI-X,
which has a legacy assumption. But that legacy fallback assumption is only
valid when legacy support is enabled, but otherwise the check should simply
return -ENOTSUPP.
Loongarch tripped over the same problem and blindly enabled legacy support
without implementing the legacy fallbacks. There are weak implementations
which return an error, so the problem was papered over.
Correct pci_msi_domain_supports() to evaluate the legacy mode and add
the missing supported check into the MSI enable path to complete it.
Fixes: d2a463b29741 ("PCI/MSI: Reject multi-MSI early")
Reported-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/87ed2a8ow5.ffs@tglx
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Fix the dtc warnings:
arch/mips/boot/dts/loongson/ls7a-pch.dtsi:68.16-416.5: Warning (interrupt_provider): /bus@10000000/pci@1a000000: '#interrupt-cells' found, but node is not an interrupt provider
arch/mips/boot/dts/loongson/ls7a-pch.dtsi:68.16-416.5: Warning (interrupt_provider): /bus@10000000/pci@1a000000: '#interrupt-cells' found, but node is not an interrupt provider
arch/mips/boot/dts/loongson/loongson64g_4core_ls7a.dtb: Warning (interrupt_map): Failed prerequisite 'interrupt_provider'
And a runtime warning introduced in commit 045b14ca5c36 ("of: WARN on
deprecated #address-cells/#size-cells handling"):
WARNING: CPU: 0 PID: 1 at drivers/of/base.c:106 of_bus_n_addr_cells+0x9c/0xe0
Missing '#address-cells' in /bus@10000000/pci@1a000000/pci_bridge@9,0
The fix is similar to commit d89a415ff8d5 ("MIPS: Loongson64: DTS: Fix PCIe
port nodes for ls7a"), which has fixed the issue for ls2k (despite its
subject mentions ls7a).
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Clang on LoongArch (18+) appears to be unaffected by the bug causing
excessive stack usage in calculate_bandwidth(). But when building DC_FP
support the stack frame size can be as large as 2816 bytes, which causes
the FRAME_WARN build warnings. So on LoongArch we allow building DC with
clang, but disable DC_FP by default.
The help message is also updated.
Tested-by: Rui Wang <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Since ttm_bo_move_null() is exactly the same as ttm_resource_free() +
ttm_bo_assign_mem(), we use ttm_bo_move_null() for the GTT --> SYSTEM
move case too. Then the code is more consistent as the SYSTEM --> GTT
move case.
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Flexible-array member `hws` in `struct clk_hw_onecell_data` is annotated
with the `counted_by()` attribute. This means that when memory is
allocated for this array, the _counter_, which in this case is member
`num` in the flexible structure, should be set to the maximum number of
elements the flexible array can contain, or fewer.
In this case, the total number of elements for the flexible array is
determined by variable `clks_num` when allocating heap space via
`devm_kzalloc()`, as shown below:
289 struct loongson2_clk_provider *clp;
...
296 for (p = data; p->name; p++)
297 clks_num++;
298
299 clp = devm_kzalloc(dev, struct_size(clp, clk_data.hws, clks_num),
300 GFP_KERNEL);
So, `clp->clk_data.num` should be set to `clks_num` or less, and not
exceed `clks_num`, as is currently the case. Otherwise, if data is
written into `clp->clk_data.hws[clks_num]`, the instrumentation
provided by the compiler won't detect the overflow, leading to a
memory corruption bug at runtime.
Fix this issue by setting `clp->clk_data.num` to `clks_num`.
Fixes: 9796ec0bd04b ("clk: clk-loongson2: Refactor driver for adding new platforms")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZzaN5MpmMr0hwHw9@kspp
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Some heap space is allocated for the flexible structure `struct
clk_hw_onecell_data` and its flexible-array member `hws` through
the composite structure `struct loongson2_clk_provider` in function
`loongson2_clk_probe()`, as shown below:
289 struct loongson2_clk_provider *clp;
...
296 for (p = data; p->name; p++)
297 clks_num++;
298
299 clp = devm_kzalloc(dev, struct_size(clp, clk_data.hws, clks_num),
300 GFP_KERNEL);
Then some data is written into the flexible array:
350 clp->clk_data.hws[p->id] = hw;
This corrupts `clk_lock`, which is the spinlock variable immediately
following the `clk_data` member in `struct loongson2_clk_provider`:
struct loongson2_clk_provider {
void __iomem *base;
struct device *dev;
struct clk_hw_onecell_data clk_data;
spinlock_t clk_lock; /* protect access to DIV registers */
};
The problem is that the flexible structure is currently placed in the
middle of `struct loongson2_clk_provider` instead of at the end.
Fix this by moving `struct clk_hw_onecell_data clk_data;` to the end of
`struct loongson2_clk_provider`. Also, add a code comment to help
prevent this from happening again in case new members are added to the
structure in the future.
This change also fixes the following -Wflex-array-member-not-at-end
warning:
drivers/clk/clk-loongson2.c:32:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Fixes: 9796ec0bd04b ("clk: clk-loongson2: Refactor driver for adding new platforms")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZzZ-cd_EFXs6qFaH@kspp
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When executing mm selftests run_vmtests.sh, there is such an error:
BUG: Bad page state in process uffd-unit-tests pfn:00000
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
flags: 0xffff0000002000(reserved|node=0|zone=0|lastcpupid=0xffff)
raw: 00ffff0000002000 ffffbf0000000008 ffffbf0000000008 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Modules linked in: snd_seq_dummy snd_seq snd_seq_device rfkill vfat fat
virtio_balloon efi_pstore virtio_net pstore net_failover failover fuse
nfnetlink virtio_scsi virtio_gpu virtio_dma_buf dm_multipath efivarfs
CPU: 2 UID: 0 PID: 1913 Comm: uffd-unit-tests Not tainted 6.12.0 #184
Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
Stack : 900000047c8ac000 0000000000000000 9000000000223a7c 900000047c8ac000
900000047c8af690 900000047c8af698 0000000000000000 900000047c8af7d8
900000047c8af7d0 900000047c8af7d0 900000047c8af5b0 0000000000000001
0000000000000001 900000047c8af698 10b3c7d53da40d26 0000010000000000
0000000000000022 0000000fffffffff fffffffffe000000 ffff800000000000
000000000000002f 0000800000000000 000000017a6d4000 90000000028f8940
0000000000000000 0000000000000000 90000000025aa5e0 9000000002905000
0000000000000000 90000000028f8940 ffff800000000000 0000000000000000
0000000000000000 0000000000000000 9000000000223a94 000000012001839c
00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
...
Call Trace:
[<9000000000223a94>] show_stack+0x5c/0x180
[<9000000001c3fd64>] dump_stack_lvl+0x6c/0xa0
[<900000000056aa08>] bad_page+0x1a0/0x1f0
[<9000000000574978>] free_unref_folios+0xbf0/0xd20
[<90000000004e65cc>] folios_put_refs+0x1a4/0x2b8
[<9000000000599a0c>] free_pages_and_swap_cache+0x164/0x260
[<9000000000547698>] tlb_batch_pages_flush+0xa8/0x1c0
[<9000000000547f30>] tlb_finish_mmu+0xa8/0x218
[<9000000000543cb8>] exit_mmap+0x1a0/0x360
[<9000000000247658>] __mmput+0x78/0x200
[<900000000025583c>] do_exit+0x43c/0xde8
[<9000000000256490>] do_group_exit+0x68/0x110
[<9000000000256554>] sys_exit_group+0x1c/0x20
[<9000000001c413b4>] do_syscall+0x94/0x130
[<90000000002216d8>] handle_syscall+0xb8/0x158
Disabling lock debugging due to kernel taint
BUG: non-zero pgtables_bytes on freeing mm: -16384
On LoongArch system, invalid huge pte entry should be invalid_pte_table
or a single _PAGE_HUGE bit rather than a zero value. And it should be
the same with invalid pmd entry, since pmd_none() is called by function
free_pgd_range() and pmd_none() return 0 by huge_pte_clear(). So single
_PAGE_HUGE bit is also treated as a valid pte table and free_pte_range()
will be called in free_pmd_range().
free_pmd_range()
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
free_pte_range(tlb, pmd, addr);
} while (pmd++, addr = next, addr != end);
Here invalid_pte_table is used for both invalid huge pte entry and
pmd entry.
Cc: stable@vger.kernel.org
Fixes: 09cfefb7fa70 ("LoongArch: Add memory management")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Performance improvement for reading /proc/interrupts on LoongArch.
On a system with n CPUs and m interrupts, there will be n*m decimal
values yielded via seq_printf(.."%10u "..) which is less efficient than
seq_put_decimal_ull_width(), stress reading /proc/interrupts indicates
~30% performance improvement with this patch (and its friends).
Signed-off-by: David Wang <00107082@163.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
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>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Now the min_delta is 0x600 (1536) for LoongArch's constant clockevent
device. For a 100MHz hardware timer this means ~15us. This is a little
big, especially for PREEMPT_RT enabled kernels. So reduce it to 100 for
PREEMPT_RT kernel, and 1000 for others (we don't want too small values
to affect performance).
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
(1) Description of Problem:
When testing BPF JIT with the latest compiler toolchains on LoongArch,
there exist some strange failed test cases, dmesg shows something like
this:
# dmesg -t | grep FAIL | head -1
... ret -3 != -3 (0xfffffffd != 0xfffffffd)FAIL ...
(2) Steps to Reproduce:
# echo 1 > /proc/sys/net/core/bpf_jit_enable
# modprobe test_bpf
(3) Additional Info:
There are no failed test cases compiled with the lower version of GCC
such as 13.3.0, while the problems only appear with higher version of
GCC such as 14.2.0.
This is because the problems were hidden by the lower version of GCC due
to redundant sign extension instructions generated by compiler, but with
optimization of higher version of GCC, the sign extension instructions
have been removed.
(4) Root Cause Analysis:
The LoongArch architecture does not expose sub-registers, and hold all
32-bit values in a sign-extended format. While BPF, on the other hand,
exposes sub-registers, and use zero-extension (similar to arm64/x86).
This has led to some subtle bugs, where a BPF JITted program has not
sign-extended the a0 register (return value in LoongArch land), passed
the return value up the kernel, for example:
| int from_bpf(void);
|
| long foo(void)
| {
| return from_bpf();
| }
Here, a0 would be 0xffffffff instead of the expected 0xffffffffffffffff.
Internally, the LoongArch JIT uses a5 as a dedicated register for BPF
return values. That is to say, the LoongArch BPF uses a5 for BPF return
values, which are zero-extended, whereas the LoongArch ABI uses a0 which
is sign-extended.
(5) Final Solution:
Keep a5 zero-extended, but explicitly sign-extend a0 (which is used
outside BPF land). Because libbpf currently defines the return value
of an ebpf program as a 32-bit unsigned integer, just use addi.w to
extend bit 31 into bits 63 through 32 of a5 to a0. This is similar to
commit 2f1b0d3d7331 ("riscv, bpf: Sign-extend return values").
Fixes: 5dc615520c4d ("LoongArch: Add BPF JIT support")
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Whenever I try to build the kernel with upcoming GCC 15 which defaults
to -std=gnu23 I get a build failure:
CC arch/loongarch/vdso/vgetcpu.o
In file included from ./include/uapi/linux/posix_types.h:5,
from ./include/uapi/linux/types.h:14,
from ./include/linux/types.h:6,
from ./include/linux/kasan-checks.h:5,
from ./include/asm-generic/rwonce.h:26,
from ./arch/loongarch/include/generated/asm/rwonce.h:1,
from ./include/linux/compiler.h:317,
from ./include/asm-generic/bug.h:5,
from ./arch/loongarch/include/asm/bug.h:60,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/mm.h:6,
from ./arch/loongarch/include/asm/vdso.h:10,
from arch/loongarch/vdso/vgetcpu.c:6:
./include/linux/stddef.h:11:9: error: expected identifier before 'false'
11 | false = 0,
| ^~~~~
./include/linux/types.h:35:33: error: two or more data types in declaration specifiers
35 | typedef _Bool bool;
| ^~~~
./include/linux/types.h:35:1: warning: useless type name in empty declaration
35 | typedef _Bool bool;
| ^~~~~~~
The kernel builds explicitly with -std=gnu11 in top Makefile, but
arch/loongarch/vdso does not use KBUILD_CFLAGS from the rest of the
kernel, just add -std=gnu11 flag to arch/loongarch/vdso/Makefile.
By the way, commit e8c07082a810 ("Kbuild: move to -std=gnu11") did a
similar change for arch/arm64/kernel/vdso32/Makefile.
Fixes: c6b99bed6b8f ("LoongArch: Add VDSO and VSYSCALL support")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
LoongArch's toolchain may change the default code model from normal to
medium. This is unnecessary for kernel, and generates some relocations
which cannot be handled by the module loader. So explicitly specify the
code model to normal in Makefile (for Rust 'normal' is 'small').
Cc: stable@vger.kernel.org
Tested-by: Haiyong Sun <sunhaiyong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
For now, it is time to remove -fno-jump-tables to enable jump table for
objtool if the compiler has -mannotate-tablejump, otherwise it is better
to remain -fno-jump-tables to keep compatibility with older compilers.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The objtool program need to analysis the control flow of each object file
generated by compiler toolchain, it needs to know all the locations that
a branch instruction may jump into, if a jump table is used, objtool has
to correlate the jump instruction with the table.
On x86 (which is the only port supported by objtool before LoongArch),
there is a relocation type on the jump instruction and directly points
to the table. But on LoongArch, the relocation is on another kind of
instruction prior to the jump instruction, and also with scheduling it
is not very easy to tell the offset of that instruction from the jump
instruction. Furthermore, because LoongArch has -fsection-anchors (often
enabled at -O1 or above) the relocation may actually points to a section
anchor instead of the table itself.
For the jump table of switch cases, a GCC patch "LoongArch: Add support
to annotate tablejump" and a Clang patch "[LoongArch] Add options for
annotate tablejump" have been merged into the upstream mainline, it can
parse the additional section ".discard.tablejump_annotate" which stores
the jump info as pairs of addresses, each pair contains the address of
jump instruction and the address of jump table.
For the jump table of computed gotos, it is indeed not easy to implement
in the compiler, especially if there is more than one computed goto in a
function such as ___bpf_prog_run(). objdump kernel/bpf/core.o shows that
there are many table jump instructions in ___bpf_prog_run(), but there are
no relocations on the table jump instructions and to the table directly on
LoongArch.
Without the help of compiler, in order to figure out the address of goto
table for the special case of ___bpf_prog_run(), since the instruction
sequence is relatively single and stable, it makes sense to add a helper
find_reloc_of_rodata_c_jump_table() to find the relocation which points
to the section ".rodata..c_jump_table".
If find_reloc_by_table_annotate() failed, it means there is no relocation
info of switch table address in ".rela.discard.tablejump_annotate", then
objtool may find the relocation info of goto table ".rodata..c_jump_table"
with find_reloc_of_rodata_c_jump_table().
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The objtool program need to analysis the control flow of each object file
generated by compiler toolchain, it needs to know all the locations that
a branch instruction may jump into, if a jump table is used, objtool has
to correlate the jump instruction with the table.
On x86 (which is the only port supported by objtool before LoongArch),
there is a relocation type on the jump instruction and directly points
to the table. But on LoongArch, the relocation is on another kind of
instruction prior to the jump instruction, and also with scheduling it
is not very easy to tell the offset of that instruction from the jump
instruction. Furthermore, because LoongArch has -fsection-anchors (often
enabled at -O1 or above) the relocation may actually points to a section
anchor instead of the table itself.
The good news is that after continuous analysis and discussion, at last
a GCC patch "LoongArch: Add support to annotate tablejump" and a Clang
patch "[LoongArch] Add options for annotate tablejump" have been merged
into the upstream mainline, the compiler changes make life much easier
for switch table support of objtool on LoongArch.
By now, there is an additional section ".discard.tablejump_annotate" to
store the jump info as pairs of addresses, each pair contains the address
of jump instruction and the address of jump table.
In order to find switch table, it is easy to parse the relocation section
".rela.discard.tablejump_annotate" to get table_sec and table_offset, the
rest process is somehow like x86.
Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=0ee028f55640
Link: https://github.com/llvm/llvm-project/commit/4c2c17756739
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When compiling with Clang on LoongArch, there are unsorted table offset
of rodata if there exist many jump tables, it will get the wrong table
end and find the wrong jump destination instructions in add_jump_table().
Sort the rodata table offset by parsing ".rela.discard.tablejump_annotate"
and then get each table size of rodata corresponded with each table jump
instruction, it is used to check the table end and will break the process
when parsing ".rela.rodata" to avoid getting the wrong jump destination
instructions.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: michael <michael5hzg@gmail.com>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Tiezhu Yang