5.15-stable review patch. If anyone has any objections, please let me know.
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From: Samuel Holland samuel.holland@sifive.com
commit 6f9dc684cae638dda0570154509884ee78d0f75c upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/Kconfig | 1 + 1 file changed, 1 insertion(+)
--- a/arch/Kconfig +++ b/arch/Kconfig @@ -605,6 +605,7 @@ config SHADOW_CALL_STACK bool "Clang Shadow Call Stack" depends on CC_IS_CLANG && ARCH_SUPPORTS_SHADOW_CALL_STACK depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER + depends on MMU help This option enables Clang's Shadow Call Stack, which uses a shadow stack to protect function return addresses from being