Add basic support to run various MIPS variants via kunit_tool using the virtualized malta platform.
Some of the cs_dsp unittests are broken. They are being disabled by default in the series "Fix up building KUnit tests for Cirrus Logic modules" [0].
[0] https://lore.kernel.org/lkml/20250411123608.1676462-1-rf@opensource.cirrus.c...
Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- Changes in v2: - Fix usercopy kunit test by handling ABI-less tasks in stack_top() - Drop change to mm initialization. The broken test is not built by default anymore. - Link to v1: https://lore.kernel.org/r/20250212-kunit-mips-v1-0-eb49c9d76615@linutronix.d...
--- Thomas Weißschuh (2): MIPS: Don't crash in stack_top() for tasks without ABI or vDSO kunit: qemu_configs: Add MIPS configurations
arch/mips/kernel/process.c | 8 +++++--- tools/testing/kunit/qemu_configs/mips.py | 18 ++++++++++++++++++ tools/testing/kunit/qemu_configs/mips64.py | 19 +++++++++++++++++++ tools/testing/kunit/qemu_configs/mips64el.py | 19 +++++++++++++++++++ tools/testing/kunit/qemu_configs/mipsel.py | 18 ++++++++++++++++++ 5 files changed, 79 insertions(+), 3 deletions(-) --- base-commit: 0466dc03fa779373afb807ce7496c404d98ace4b change-id: 20241014-kunit-mips-e4fe1c265ed7
Best regards,
Not all tasks have an ABI associated or vDSO mapped, for example kthreads never do. If such a task ever ends up calling stack_top(), it will derefence the NULL vdso pointer and crash.
This can for example happen when using kunit:
mips_stack_top+0x28/0xc0 arch_pick_mmap_layout+0x190/0x220 kunit_vm_mmap_init+0xf8/0x138 __kunit_add_resource+0x40/0xa8 kunit_vm_mmap+0x88/0xd8 usercopy_test_init+0xb8/0x240 kunit_try_run_case+0x5c/0x1a8 kunit_generic_run_threadfn_adapter+0x28/0x50 kthread+0x118/0x240 ret_from_kernel_thread+0x14/0x1c
Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- arch/mips/kernel/process.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index b630604c577f9ff3f2493b0f254363e499c8318c..66343cb6c1737c4217ddd8a2c3ca244fac0ef8a5 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -690,9 +690,11 @@ unsigned long mips_stack_top(void) }
/* Space for the VDSO, data page & GIC user page */ - top -= PAGE_ALIGN(current->thread.abi->vdso->size); - top -= PAGE_SIZE; - top -= mips_gic_present() ? PAGE_SIZE : 0; + if (current->thread.abi) { + top -= PAGE_ALIGN(current->thread.abi->vdso->size); + top -= PAGE_SIZE; + top -= mips_gic_present() ? PAGE_SIZE : 0; + }
/* Space for cache colour alignment */ if (cpu_has_dc_aliases)
Hi, Thomas,
On Mon, Apr 14, 2025 at 4:29 PM Thomas Weißschuh thomas.weissschuh@linutronix.de wrote:
Not all tasks have an ABI associated or vDSO mapped, for example kthreads never do. If such a task ever ends up calling stack_top(), it will derefence the NULL vdso pointer and crash.
This can for example happen when using kunit:
mips_stack_top+0x28/0xc0 arch_pick_mmap_layout+0x190/0x220 kunit_vm_mmap_init+0xf8/0x138 __kunit_add_resource+0x40/0xa8 kunit_vm_mmap+0x88/0xd8 usercopy_test_init+0xb8/0x240 kunit_try_run_case+0x5c/0x1a8 kunit_generic_run_threadfn_adapter+0x28/0x50 kthread+0x118/0x240 ret_from_kernel_thread+0x14/0x1cSigned-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de
arch/mips/kernel/process.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index b630604c577f9ff3f2493b0f254363e499c8318c..66343cb6c1737c4217ddd8a2c3ca244fac0ef8a5 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -690,9 +690,11 @@ unsigned long mips_stack_top(void) }
/* Space for the VDSO, data page & GIC user page */
top -= PAGE_ALIGN(current->thread.abi->vdso->size);top -= PAGE_SIZE;top -= mips_gic_present() ? PAGE_SIZE : 0;
if (current->thread.abi) {top -= PAGE_ALIGN(current->thread.abi->vdso->size);top -= PAGE_SIZE;top -= mips_gic_present() ? PAGE_SIZE : 0;}
I think the below code should also exist only when VDSO exists.
if (current->flags & PF_RANDOMIZE) top -= VDSO_RANDOMIZE_SIZE;
Huacai
/* Space for cache colour alignment */ if (cpu_has_dc_aliases)-- 2.49.0
On Mon, Apr 14, 2025 at 05:32:47PM +0800, Huacai Chen wrote:
Hi, Thomas,
On Mon, Apr 14, 2025 at 4:29 PM Thomas Weißschuh thomas.weissschuh@linutronix.de wrote:
Not all tasks have an ABI associated or vDSO mapped, for example kthreads never do. If such a task ever ends up calling stack_top(), it will derefence the NULL vdso pointer and crash.
This can for example happen when using kunit:
mips_stack_top+0x28/0xc0 arch_pick_mmap_layout+0x190/0x220 kunit_vm_mmap_init+0xf8/0x138 __kunit_add_resource+0x40/0xa8 kunit_vm_mmap+0x88/0xd8 usercopy_test_init+0xb8/0x240 kunit_try_run_case+0x5c/0x1a8 kunit_generic_run_threadfn_adapter+0x28/0x50 kthread+0x118/0x240 ret_from_kernel_thread+0x14/0x1cSigned-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de
arch/mips/kernel/process.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index b630604c577f9ff3f2493b0f254363e499c8318c..66343cb6c1737c4217ddd8a2c3ca244fac0ef8a5 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -690,9 +690,11 @@ unsigned long mips_stack_top(void) }
/* Space for the VDSO, data page & GIC user page */
top -= PAGE_ALIGN(current->thread.abi->vdso->size);top -= PAGE_SIZE;top -= mips_gic_present() ? PAGE_SIZE : 0;
if (current->thread.abi) {top -= PAGE_ALIGN(current->thread.abi->vdso->size);top -= PAGE_SIZE;top -= mips_gic_present() ? PAGE_SIZE : 0;}I think the below code should also exist only when VDSO exists.
if (current->flags & PF_RANDOMIZE) top -= VDSO_RANDOMIZE_SIZE;
Good point, thanks. I'll move that up into the same new conditional block.
Huacai
/* Space for cache colour alignment */ if (cpu_has_dc_aliases)-- 2.49.0
Add basic support to run various MIPS variants via kunit_tool using the virtualized malta platform.
Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- tools/testing/kunit/qemu_configs/mips.py | 18 ++++++++++++++++++ tools/testing/kunit/qemu_configs/mips64.py | 19 +++++++++++++++++++ tools/testing/kunit/qemu_configs/mips64el.py | 19 +++++++++++++++++++ tools/testing/kunit/qemu_configs/mipsel.py | 18 ++++++++++++++++++ 4 files changed, 74 insertions(+)
diff --git a/tools/testing/kunit/qemu_configs/mips.py b/tools/testing/kunit/qemu_configs/mips.py new file mode 100644 index 0000000000000000000000000000000000000000..8899ac157b30bd2ee847eacd5b90fe6ad4e5fb04 --- /dev/null +++ b/tools/testing/kunit/qemu_configs/mips.py @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +from ..qemu_config import QemuArchParams + +QEMU_ARCH = QemuArchParams(linux_arch='mips', + kconfig=''' +CONFIG_32BIT=y +CONFIG_CPU_BIG_ENDIAN=y +CONFIG_MIPS_MALTA=y +CONFIG_SERIAL_8250=y +CONFIG_SERIAL_8250_CONSOLE=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_SYSCON=y +''', + qemu_arch='mips', + kernel_path='vmlinuz', + kernel_command_line='console=ttyS0', + extra_qemu_params=['-M', 'malta']) diff --git a/tools/testing/kunit/qemu_configs/mips64.py b/tools/testing/kunit/qemu_configs/mips64.py new file mode 100644 index 0000000000000000000000000000000000000000..1478aed05b94da4914f34c6a8affdcfe34eb88ea --- /dev/null +++ b/tools/testing/kunit/qemu_configs/mips64.py @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0 + +from ..qemu_config import QemuArchParams + +QEMU_ARCH = QemuArchParams(linux_arch='mips', + kconfig=''' +CONFIG_CPU_MIPS64_R2=y +CONFIG_64BIT=y +CONFIG_CPU_BIG_ENDIAN=y +CONFIG_MIPS_MALTA=y +CONFIG_SERIAL_8250=y +CONFIG_SERIAL_8250_CONSOLE=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_SYSCON=y +''', + qemu_arch='mips64', + kernel_path='vmlinuz', + kernel_command_line='console=ttyS0', + extra_qemu_params=['-M', 'malta', '-cpu', '5KEc']) diff --git a/tools/testing/kunit/qemu_configs/mips64el.py b/tools/testing/kunit/qemu_configs/mips64el.py new file mode 100644 index 0000000000000000000000000000000000000000..300c711d7a82500b2ebcb4cf1467b6f72b5c17aa --- /dev/null +++ b/tools/testing/kunit/qemu_configs/mips64el.py @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0 + +from ..qemu_config import QemuArchParams + +QEMU_ARCH = QemuArchParams(linux_arch='mips', + kconfig=''' +CONFIG_CPU_MIPS64_R2=y +CONFIG_64BIT=y +CONFIG_CPU_LITTLE_ENDIAN=y +CONFIG_MIPS_MALTA=y +CONFIG_SERIAL_8250=y +CONFIG_SERIAL_8250_CONSOLE=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_SYSCON=y +''', + qemu_arch='mips64el', + kernel_path='vmlinuz', + kernel_command_line='console=ttyS0', + extra_qemu_params=['-M', 'malta', '-cpu', '5KEc']) diff --git a/tools/testing/kunit/qemu_configs/mipsel.py b/tools/testing/kunit/qemu_configs/mipsel.py new file mode 100644 index 0000000000000000000000000000000000000000..3d3543315b45776d0e77fb5c00c8c0a89eafdffd --- /dev/null +++ b/tools/testing/kunit/qemu_configs/mipsel.py @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +from ..qemu_config import QemuArchParams + +QEMU_ARCH = QemuArchParams(linux_arch='mips', + kconfig=''' +CONFIG_32BIT=y +CONFIG_CPU_LITTLE_ENDIAN=y +CONFIG_MIPS_MALTA=y +CONFIG_SERIAL_8250=y +CONFIG_SERIAL_8250_CONSOLE=y +CONFIG_POWER_RESET=y +CONFIG_POWER_RESET_SYSCON=y +''', + qemu_arch='mipsel', + kernel_path='vmlinuz', + kernel_command_line='console=ttyS0', + extra_qemu_params=['-M', 'malta'])
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Thomas Weißschuh