From: Christophe Leroy <christophe.leroy@xxxxxxxxxx> [ Upstream commit ca5dabcff1df6bc8c413922b5fa63cc602858803 ] When CONFIG_KASAN is selected, we expect prom_init to use __memset() because it is too early to use memset(). But with CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL, the compiler adds calls to memset() to clear objects on stack, hence the following failure: PROMCHK arch/powerpc/kernel/prom_init_check Error: External symbol 'memset' referenced from prom_init.c make[2]: *** [arch/powerpc/kernel/Makefile:204 : arch/powerpc/kernel/prom_init_check] Erreur 1 prom_find_machine_type() is called from prom_init() and is called only once, so lets put compat[] in BSS instead of stack to avoid that. Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/3802811f7cf94f730be44688539c01bba3a3b5c0.1654875808.git.christophe.leroy@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/powerpc/kernel/prom_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 0ac5faacc909..46247645c134 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -2300,7 +2300,7 @@ static void __init prom_init_stdout(void) static int __init prom_find_machine_type(void) { - char compat[256]; + static char compat[256] __prombss; int len, i = 0; #ifdef CONFIG_PPC64 phandle rtas; -- 2.35.1