The patch titled Subject: scs: add CONFIG_MMU dependency for vfree_atomic() has been added to the -mm mm-hotfixes-unstable branch. Its filename is scs-add-config_mmu-dependency-for-vfree_atomic.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days

------------------------------------------------------ From: Samuel Holland samuel.holland@sifive.com Subject: scs: add CONFIG_MMU dependency for vfree_atomic() Date: Mon, 22 Jan 2024 09:52:01 -0800

The shadow call stack implementation fails to build without CONFIG_MMU:

ld.lld: error: undefined symbol: vfree_atomic

...

...

referenced by scs.c kernel/scs.o:(scs_free) in archive vmlinux.a

Link: https://lkml.kernel.org/r/20240122175204.2371009-1-samuel.holland@sifive.com Fixes: a2abe7cbd8fe ("scs: switch to vmapped shadow stacks") Signed-off-by: Samuel Holland samuel.holland@sifive.com Reviewed-by: Sami Tolvanen samitolvanen@google.com Cc: Will Deacon will@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

arch/Kconfig | 1 + 1 file changed, 1 insertion(+)

--- a/arch/Kconfig~scs-add-config_mmu-dependency-for-vfree_atomic +++ a/arch/Kconfig @@ -668,6 +668,7 @@ config SHADOW_CALL_STACK bool "Shadow Call Stack" depends on ARCH_SUPPORTS_SHADOW_CALL_STACK depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER + depends on MMU help This option enables the compiler's Shadow Call Stack, which uses a shadow stack to protect function return addresses from _

Patches currently in -mm which might be from samuel.holland@sifive.com are

scs-add-config_mmu-dependency-for-vfree_atomic.patch