arm64: BUG: KASAN: invalid-access in arch_stack_walk

DISCUSSION Breno Leitao 3 participants 5 messages Jun 20, 2025 – Jun 24, 2025

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Breno Leitao

author

2025-06-20 12:58 UTC #0 lore raw

I'm encountering a KASAN warning during aarch64 boot and I am struggling to determine the cause. I haven't come across any reports about this on the mailing list so far, so I'm sharing this early in case others are seeing it too.

This issue occurs both on Linus's upstream branch and in the 6.15 final release. The stack trace below is from 6.15 final. I haven't started bisecting yet, but that's my next step.

Here are a few details about the problem:

1) it happen on my kernel boots on a aarch64 host
2) The lines do not match the code very well, and I am not sure why. It seems it is offset by two lines. The stack is based on commit 0ff41df1cb26 ("Linux 6.15")
3) My config is at https://pastebin.com/ye46bEK9

	[  235.831690] ==================================================================
	[  235.861238] BUG: KASAN: invalid-access in arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
	[  235.887206] Write of size 96 at addr a5ff80008ae8fb80 by task kworker/u288:26/3666
	[  235.918139] Pointer tag: [a5], memory tag: [00]
	[  235.942722] Workqueue: efi_rts_wq efi_call_rts
	[  235.942732] Call trace:
	[  235.942734] show_stack (arch/arm64/kernel/stacktrace.c:468) (C)
	[  235.942741] dump_stack_lvl (lib/dump_stack.c:123)
	[  235.942748] print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)
	[  235.942755] kasan_report (mm/kasan/report.c:636)
	[  235.942759] kasan_check_range (mm/kasan/sw_tags.c:85)
	[  235.942764] memset (mm/kasan/shadow.c:53)
	[  235.942769] arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
	[  235.942773] return_address (arch/arm64/kernel/return_address.c:44)
	[  235.942778] trace_hardirqs_off.part.0 (kernel/trace/trace_preemptirq.c:95)
	[  235.942784] trace_hardirqs_off_finish (kernel/trace/trace_preemptirq.c:98)
	[  235.942789] enter_from_kernel_mode (arch/arm64/kernel/entry-common.c:62)
	[  235.942794] el1_interrupt (arch/arm64/kernel/entry-common.c:559 arch/arm64/kernel/entry-common.c:575)
	[  235.942799] el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:581)
	[  235.942804] el1h_64_irq (arch/arm64/kernel/entry.S:596)
	[  235.942809]  0x3c52ff1ecc (P)
	[  235.942825]  0x3c52ff0ed4
	[  235.942829]  0x3c52f902d0
	[  235.942833]  0x3c52f953e8
	[  235.942837] __efi_rt_asm_wrapper (arch/arm64/kernel/efi-rt-wrapper.S:49)
	[  235.942843] efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:269)
	[  235.942848] process_one_work (./arch/arm64/include/asm/jump_label.h:36 ./include/trace/events/workqueue.h:110 kernel/workqueue.c:3243)
	[  235.942854] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400)
	[  235.942858] kthread (kernel/kthread.c:464)
	[  235.942863] ret_from_fork (arch/arm64/kernel/entry.S:863)

	[  236.436924] The buggy address belongs to the virtual mapping at
	[a5ff80008ae80000, a5ff80008aea0000) created by:
	arm64_efi_rt_init (arch/arm64/kernel/efi.c:219)

	[  236.506959] The buggy address belongs to the physical page:
	[  236.529724] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12682
	[  236.562077] flags: 0x17fffd6c0000000(node=0|zone=2|lastcpupid=0x1ffff|kasantag=0x5b)
	[  236.593722] raw: 017fffd6c0000000 0000000000000000 dead000000000122 0000000000000000
	[  236.625365] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
	[  236.657004] page dumped because: kasan: bad access detected

	[  236.685828] Memory state around the buggy address:
	[  236.705390]  ffff80008ae8f900: 00 00 00 00 00 a5 a5 a5 a5 00 00 00 00 00 a5 a5
	[  236.734899]  ffff80008ae8fa00: a5 a5 a5 00 00 00 00 00 00 a5 a5 a5 a5 a5 00 a5
	[  236.764409] >ffff80008ae8fb00: 00 a5 a5 a5 00 a5 a5 a5 a5 a5 a5 00 a5 a5 a5 00
	[  236.793918]                                                     ^
	[  236.818810]  ffff80008ae8fc00: a7 a5 a5 a5 a5 a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5
	[  236.848321]  ffff80008ae8fd00: a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5 a5 a5 a5 a5 a5
	[  236.877828] ==================================================================

Andrey Konovalov

2025-06-22 13:00 UTC #1 lore raw

Quoted 61 lines · Breno Leitao

This issue occurs both on Linus's upstream branch and in the 6.15 final release. The stack trace below is from 6.15 final. I haven't started bisecting yet, but that's my next step.

Here are a few details about the problem:

        [  235.831690] ==================================================================
        [  235.861238] BUG: KASAN: invalid-access in arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.887206] Write of size 96 at addr a5ff80008ae8fb80 by task kworker/u288:26/3666
        [  235.918139] Pointer tag: [a5], memory tag: [00]
        [  235.942722] Workqueue: efi_rts_wq efi_call_rts
        [  235.942732] Call trace:
        [  235.942734] show_stack (arch/arm64/kernel/stacktrace.c:468) (C)
        [  235.942741] dump_stack_lvl (lib/dump_stack.c:123)
        [  235.942748] print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)
        [  235.942755] kasan_report (mm/kasan/report.c:636)
        [  235.942759] kasan_check_range (mm/kasan/sw_tags.c:85)
        [  235.942764] memset (mm/kasan/shadow.c:53)
        [  235.942769] arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.942773] return_address (arch/arm64/kernel/return_address.c:44)
        [  235.942778] trace_hardirqs_off.part.0 (kernel/trace/trace_preemptirq.c:95)
        [  235.942784] trace_hardirqs_off_finish (kernel/trace/trace_preemptirq.c:98)
        [  235.942789] enter_from_kernel_mode (arch/arm64/kernel/entry-common.c:62)
        [  235.942794] el1_interrupt (arch/arm64/kernel/entry-common.c:559 arch/arm64/kernel/entry-common.c:575)
        [  235.942799] el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:581)
        [  235.942804] el1h_64_irq (arch/arm64/kernel/entry.S:596)
        [  235.942809]  0x3c52ff1ecc (P)
        [  235.942825]  0x3c52ff0ed4
        [  235.942829]  0x3c52f902d0
        [  235.942833]  0x3c52f953e8
        [  235.942837] __efi_rt_asm_wrapper (arch/arm64/kernel/efi-rt-wrapper.S:49)
        [  235.942843] efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:269)
        [  235.942848] process_one_work (./arch/arm64/include/asm/jump_label.h:36 ./include/trace/events/workqueue.h:110 kernel/workqueue.c:3243)
        [  235.942854] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400)
        [  235.942858] kthread (kernel/kthread.c:464)
        [  235.942863] ret_from_fork (arch/arm64/kernel/entry.S:863)

        [  236.436924] The buggy address belongs to the virtual mapping at
        [a5ff80008ae80000, a5ff80008aea0000) created by:
        arm64_efi_rt_init (arch/arm64/kernel/efi.c:219)

        [  236.506959] The buggy address belongs to the physical page:
        [  236.529724] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12682
        [  236.562077] flags: 0x17fffd6c0000000(node=0|zone=2|lastcpupid=0x1ffff|kasantag=0x5b)
        [  236.593722] raw: 017fffd6c0000000 0000000000000000 dead000000000122 0000000000000000
        [  236.625365] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
        [  236.657004] page dumped because: kasan: bad access detected

Quoted 8 lines

        [  236.685828] Memory state around the buggy address:
        [  236.705390]  ffff80008ae8f900: 00 00 00 00 00 a5 a5 a5 a5 00 00 00 00 00 a5 a5
        [  236.734899]  ffff80008ae8fa00: a5 a5 a5 00 00 00 00 00 00 a5 a5 a5 a5 a5 00 a5
        [  236.764409] >ffff80008ae8fb00: 00 a5 a5 a5 00 a5 a5 a5 a5 a5 a5 00 a5 a5 a5 00
        [  236.793918]                                                     ^
        [  236.818810]  ffff80008ae8fc00: a7 a5 a5 a5 a5 a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5
        [  236.848321]  ffff80008ae8fd00: a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5 a5 a5 a5 a5 a5
        [  236.877828] ==================================================================

Looks like the memory allocated/mapped in arm64_efi_rt_init() is tagged by __vmalloc_node(). And this memory then gets used as a (irq-related? EFI-related?) stack. And having the SP register tagged breaks SW_TAGS instrumentation AFAIR [1], which is likely what produces this report.

Adding kasan_reset_tag() to arm64_efi_rt_init() should likely fix this; similar to what we have in arch_alloc_vmap_stack(). Or should we make arm64_efi_rt_init() just call arch_alloc_vmap_stack()?

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=51fb34de2a4c8fa0f221246313700bfe3b6c586d

Catalin Marinas

2025-06-23 20:06 UTC #2 lore raw

Quoted 76 lines · Andrey Konovalov

Quoted 60 lines · Breno Leitao

This issue occurs both on Linus's upstream branch and in the 6.15 final release. The stack trace below is from 6.15 final. I haven't started bisecting yet, but that's my next step.

Here are a few details about the problem:

        [  235.831690] ==================================================================
        [  235.861238] BUG: KASAN: invalid-access in arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.887206] Write of size 96 at addr a5ff80008ae8fb80 by task kworker/u288:26/3666
        [  235.918139] Pointer tag: [a5], memory tag: [00]
        [  235.942722] Workqueue: efi_rts_wq efi_call_rts
        [  235.942732] Call trace:
        [  235.942734] show_stack (arch/arm64/kernel/stacktrace.c:468) (C)
        [  235.942741] dump_stack_lvl (lib/dump_stack.c:123)
        [  235.942748] print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)
        [  235.942755] kasan_report (mm/kasan/report.c:636)
        [  235.942759] kasan_check_range (mm/kasan/sw_tags.c:85)
        [  235.942764] memset (mm/kasan/shadow.c:53)
        [  235.942769] arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.942773] return_address (arch/arm64/kernel/return_address.c:44)
        [  235.942778] trace_hardirqs_off.part.0 (kernel/trace/trace_preemptirq.c:95)
        [  235.942784] trace_hardirqs_off_finish (kernel/trace/trace_preemptirq.c:98)
        [  235.942789] enter_from_kernel_mode (arch/arm64/kernel/entry-common.c:62)
        [  235.942794] el1_interrupt (arch/arm64/kernel/entry-common.c:559 arch/arm64/kernel/entry-common.c:575)
        [  235.942799] el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:581)
        [  235.942804] el1h_64_irq (arch/arm64/kernel/entry.S:596)
        [  235.942809]  0x3c52ff1ecc (P)
        [  235.942825]  0x3c52ff0ed4
        [  235.942829]  0x3c52f902d0
        [  235.942833]  0x3c52f953e8
        [  235.942837] __efi_rt_asm_wrapper (arch/arm64/kernel/efi-rt-wrapper.S:49)
        [  235.942843] efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:269)
        [  235.942848] process_one_work (./arch/arm64/include/asm/jump_label.h:36 ./include/trace/events/workqueue.h:110 kernel/workqueue.c:3243)
        [  235.942854] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400)
        [  235.942858] kthread (kernel/kthread.c:464)
        [  235.942863] ret_from_fork (arch/arm64/kernel/entry.S:863)

        [  236.436924] The buggy address belongs to the virtual mapping at
        [a5ff80008ae80000, a5ff80008aea0000) created by:
        arm64_efi_rt_init (arch/arm64/kernel/efi.c:219)

        [  236.506959] The buggy address belongs to the physical page:
        [  236.529724] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12682
        [  236.562077] flags: 0x17fffd6c0000000(node=0|zone=2|lastcpupid=0x1ffff|kasantag=0x5b)
        [  236.593722] raw: 017fffd6c0000000 0000000000000000 dead000000000122 0000000000000000
        [  236.625365] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
        [  236.657004] page dumped because: kasan: bad access detected

Quoted 8 lines

        [  236.685828] Memory state around the buggy address:
        [  236.705390]  ffff80008ae8f900: 00 00 00 00 00 a5 a5 a5 a5 00 00 00 00 00 a5 a5
        [  236.734899]  ffff80008ae8fa00: a5 a5 a5 00 00 00 00 00 00 a5 a5 a5 a5 a5 00 a5
        [  236.764409] >ffff80008ae8fb00: 00 a5 a5 a5 00 a5 a5 a5 a5 a5 a5 00 a5 a5 a5 00
        [  236.793918]                                                     ^
        [  236.818810]  ffff80008ae8fc00: a7 a5 a5 a5 a5 a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5
        [  236.848321]  ffff80008ae8fd00: a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5 a5 a5 a5 a5 a5
        [  236.877828] ==================================================================

Quoted 3 lines

Adding kasan_reset_tag() to arm64_efi_rt_init() should likely fix this; similar to what we have in arch_alloc_vmap_stack(). Or should we make arm64_efi_rt_init() just call arch_alloc_vmap_stack()?

In theory, we can still disable the vmap stack, so we either fall back to something else or require that EFI runtime depends on VMAP_STACK. We can do like init_sdei_stacks(), just bail out if VMAP_STACK is disabled.

Adding Ard, it's his code.

Quoted 1 line

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=51fb34de2a4c8fa0f221246313700bfe3b6c586d

Signature · 1 line

Catalin

Breno Leitao

author

2025-06-23 21:41 UTC #3 lore raw

Quoted 77 lines · Catalin Marinas

Quoted 76 lines · Andrey Konovalov

Quoted 60 lines · Breno Leitao

This issue occurs both on Linus's upstream branch and in the 6.15 final release. The stack trace below is from 6.15 final. I haven't started bisecting yet, but that's my next step.

Here are a few details about the problem:

        [  235.831690] ==================================================================
        [  235.861238] BUG: KASAN: invalid-access in arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.887206] Write of size 96 at addr a5ff80008ae8fb80 by task kworker/u288:26/3666
        [  235.918139] Pointer tag: [a5], memory tag: [00]
        [  235.942722] Workqueue: efi_rts_wq efi_call_rts
        [  235.942732] Call trace:
        [  235.942734] show_stack (arch/arm64/kernel/stacktrace.c:468) (C)
        [  235.942741] dump_stack_lvl (lib/dump_stack.c:123)
        [  235.942748] print_report (mm/kasan/report.c:409 mm/kasan/report.c:521)
        [  235.942755] kasan_report (mm/kasan/report.c:636)
        [  235.942759] kasan_check_range (mm/kasan/sw_tags.c:85)
        [  235.942764] memset (mm/kasan/shadow.c:53)
        [  235.942769] arch_stack_walk (arch/arm64/kernel/stacktrace.c:346 arch/arm64/kernel/stacktrace.c:387)
        [  235.942773] return_address (arch/arm64/kernel/return_address.c:44)
        [  235.942778] trace_hardirqs_off.part.0 (kernel/trace/trace_preemptirq.c:95)
        [  235.942784] trace_hardirqs_off_finish (kernel/trace/trace_preemptirq.c:98)
        [  235.942789] enter_from_kernel_mode (arch/arm64/kernel/entry-common.c:62)
        [  235.942794] el1_interrupt (arch/arm64/kernel/entry-common.c:559 arch/arm64/kernel/entry-common.c:575)
        [  235.942799] el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:581)
        [  235.942804] el1h_64_irq (arch/arm64/kernel/entry.S:596)
        [  235.942809]  0x3c52ff1ecc (P)
        [  235.942825]  0x3c52ff0ed4
        [  235.942829]  0x3c52f902d0
        [  235.942833]  0x3c52f953e8
        [  235.942837] __efi_rt_asm_wrapper (arch/arm64/kernel/efi-rt-wrapper.S:49)
        [  235.942843] efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:269)
        [  235.942848] process_one_work (./arch/arm64/include/asm/jump_label.h:36 ./include/trace/events/workqueue.h:110 kernel/workqueue.c:3243)
        [  235.942854] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400)
        [  235.942858] kthread (kernel/kthread.c:464)
        [  235.942863] ret_from_fork (arch/arm64/kernel/entry.S:863)

        [  236.436924] The buggy address belongs to the virtual mapping at
        [a5ff80008ae80000, a5ff80008aea0000) created by:
        arm64_efi_rt_init (arch/arm64/kernel/efi.c:219)

        [  236.506959] The buggy address belongs to the physical page:
        [  236.529724] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12682
        [  236.562077] flags: 0x17fffd6c0000000(node=0|zone=2|lastcpupid=0x1ffff|kasantag=0x5b)
        [  236.593722] raw: 017fffd6c0000000 0000000000000000 dead000000000122 0000000000000000
        [  236.625365] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
        [  236.657004] page dumped because: kasan: bad access detected

Quoted 8 lines

        [  236.685828] Memory state around the buggy address:
        [  236.705390]  ffff80008ae8f900: 00 00 00 00 00 a5 a5 a5 a5 00 00 00 00 00 a5 a5
        [  236.734899]  ffff80008ae8fa00: a5 a5 a5 00 00 00 00 00 00 a5 a5 a5 a5 a5 00 a5
        [  236.764409] >ffff80008ae8fb00: 00 a5 a5 a5 00 a5 a5 a5 a5 a5 a5 00 a5 a5 a5 00
        [  236.793918]                                                     ^
        [  236.818810]  ffff80008ae8fc00: a7 a5 a5 a5 a5 a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5
        [  236.848321]  ffff80008ae8fd00: a5 a5 a5 a5 00 a5 00 a5 a5 a5 a5 a5 a5 a5 a5 a5
        [  236.877828] ==================================================================

Quoted 8 lines

Quoted 3 lines
Adding kasan_reset_tag() to arm64_efi_rt_init() should likely fix this; similar to what we have in arch_alloc_vmap_stack(). Or should we make arm64_efi_rt_init() just call arch_alloc_vmap_stack()?
In theory, we can still disable the vmap stack, so we either fall back to something else or require that EFI runtime depends on VMAP_STACK. We can do like init_sdei_stacks(), just bail out if VMAP_STACK is disabled.

Thanks for the feedback and suggestions. Are we talking about a patch that looks like the following:

	Author: Breno Leitao <[email protected]>
	Date:   Mon Jun 23 09:46:54 2025 -0700

	arm64: Use arch_alloc_vmap_stack for EFI runtime stack allocation
	
	Refactor vmap stack allocation by moving the CONFIG_VMAP_STACK check
	from BUILD_BUG_ON to a runtime return of NULL if the config is not set.
	The side effect of this is that _init_sdei_stack() might NOT fail in
	build time if _VMAP_STACK, but in runtime. It shifts error
	detection from compile-time to runtime
	
	Then, reuse arch_alloc_vmap_stack() to allocate the ACPI stack
	memory in the arm64_efi_rt_init().
	
	Suggested-by: Andrey Konovalov <[email protected]>
	Suggested-by: Catalin Marinas <[email protected]>
	Signed-off-by: Breno Leitao <[email protected]>

	diff --git a/arch/arm64/include/asm/vmap_stack.h b/arch/arm64/include/asm/vmap_stack.h
	index 20873099c035c..8380af4507d01 100644
	--- a/arch/arm64/include/asm/vmap_stack.h
	+++ b/arch/arm64/include/asm/vmap_stack.h
	@@ -19,7 +19,8 @@ static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node)
	{
		void *p;
	
	-	BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK));
	+	if (!IS_ENABLED(CONFIG_VMAP_STACK))
	+		return NULL;
	
		p = __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node,
				__builtin_return_address(0));
	diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
	index 3857fd7ee8d46..6c371b158b99f 100644
	--- a/arch/arm64/kernel/efi.c
	+++ b/arch/arm64/kernel/efi.c
	@@ -15,6 +15,7 @@
	
	#include <asm/efi.h>
	#include <asm/stacktrace.h>
	+#include <asm/vmap_stack.h>
	
	static bool region_is_misaligned(const efi_memory_desc_t *md)
	{
	@@ -214,9 +215,8 @@ static int __init arm64_efi_rt_init(void)
		if (!efi_enabled(EFI_RUNTIME_SERVICES))
			return 0;
	
	-	p = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, GFP_KERNEL,
	-			   NUMA_NO_NODE, &&l);
	-l:	if (!p) {
	+	p = arch_alloc_vmap_stack(THREAD_SIZE, NUMA_NO_NODE);
	+	if (!p) {
			pr_warn("Failed to allocate EFI runtime stack\n");
			clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
			return -ENOMEM;

Catalin Marinas

2025-06-24 09:07 UTC #4 lore raw

Quoted 7 lines · Breno Leitao

arm64: Use arch_alloc_vmap_stack for EFI runtime stack allocation
Refactor vmap stack allocation by moving the CONFIG_VMAP_STACK check from BUILD_BUG_ON to a runtime return of NULL if the config is not set. The side effect of this is that _init_sdei_stack() might NOT fail in build time if _VMAP_STACK, but in runtime. It shifts error detection from compile-time to runtime

_init_sdei_stack() is only called from init_sdei_stacks() if CONFIG_VMAP_STACK is enabled.

Quoted 12 lines

Then, reuse arch_alloc_vmap_stack() to allocate the ACPI stack memory in the arm64_efi_rt_init().
Suggested-by Andrey Konovalov <[email protected]>
Suggested-by Catalin Marinas <[email protected]>
Signed-off-by Breno Leitao <[email protected]>
arch/arm64/include/asm/vmap_stack.h +0 -0
index 20873099c035c..8380af4507d01 100644

arch/arm64/include/asm/vmap_stack.h static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node) · line 26

Quoted 9 lines

arch/arm64/include/asm/vmap_stack.h +2 -1

@@ -19,7 +19,8 @@ static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node)
 {
 	void *p;
 
-	BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK));
+	if (!IS_ENABLED(CONFIG_VMAP_STACK))
+		return NULL;
 
 	p = __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node,
 			__builtin_return_address(0));

We can leave this unchanged to catch possible misuses in the future.

Quoted 13 lines

arch/arm64/kernel/efi.c +1 -0

index 3857fd7ee8d46..6c371b158b99f 100644
@@ -15,6 +15,7 @@
 
 #include <asm/efi.h>
 #include <asm/stacktrace.h>
+#include <asm/vmap_stack.h>
 
 static bool region_is_misaligned(const efi_memory_desc_t *md)
 {

arch/arm64/kernel/efi.c static int __init arm64_efi_rt_init(void) · line 218

Quoted 7 lines

arch/arm64/kernel/efi.c +1 -3

@@ -214,9 +215,8 @@ static int __init arm64_efi_rt_init(void)
 	if (!efi_enabled(EFI_RUNTIME_SERVICES))
 		return 0;
 
-	p = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, GFP_KERNEL,
-			   NUMA_NO_NODE, &&l);
-l:	if (!p) {
+	p = arch_alloc_vmap_stack(THREAD_SIZE, NUMA_NO_NODE);

and bail out earlier here similar to init_sdei_stacks():

	if (!IS_ENABLED(CONFIG_VMAP_STACK))
		return -ENOMEM;

Quoted 4 lines

arch/arm64/kernel/efi.c +1 -0

+	if (!p) {
 		pr_warn("Failed to allocate EFI runtime stack\n");
 		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 		return -ENOMEM;

Signature · 1 line

Catalin