From de1c831a7898f164c1c2703c6b2b9e4fb4bebefc Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 15 Apr 2025 10:02:33 -0700 Subject: slab: Decouple slab_debug and no_hash_pointers Some system owners use slab_debug=FPZ (or similar) as a hardening option, but do not want to be forced into having kernel addresses exposed due to the implicit "no_hash_pointers" boot param setting.[1] Introduce the "hash_pointers" boot param, which defaults to "auto" (the current behavior), but also includes "always" (forcing on hashing even when "slab_debug=..." is defined), and "never". The existing "no_hash_pointers" boot param becomes an alias for "hash_pointers=never". This makes it possible to boot with "slab_debug=FPZ hash_pointers=always". Link: https://github.com/KSPP/linux/issues/368 [1] Fixes: 792702911f58 ("slub: force on no_hash_pointers when slub_debug is enabled") Co-developed-by: Sergio Perez Gonzalez Signed-off-by: Sergio Perez Gonzalez Acked-by: Vlastimil Babka Acked-by: David Rientjes Reviewed-by: Bagas Sanjaya Signed-off-by: Kees Cook Reviewed-by: Harry Yoo Acked-by: Rafael Aquini Tested-by: Petr Mladek Reviewed-by: Petr Mladek Link: https://patch.msgid.link/20250415170232.it.467-kees@kernel.org [kees@kernel.org: Add note about hash_pointers into slab_debug kernel parameter documentation.] Signed-off-by: Petr Mladek --- include/linux/sprintf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/sprintf.h') diff --git a/include/linux/sprintf.h b/include/linux/sprintf.h index 51cab2def9ec..521bb2cd2648 100644 --- a/include/linux/sprintf.h +++ b/include/linux/sprintf.h @@ -22,7 +22,7 @@ __scanf(2, 0) int vsscanf(const char *, const char *, va_list); /* These are for specific cases, do not use without real need */ extern bool no_hash_pointers; -int no_hash_pointers_enable(char *str); +void hash_pointers_finalize(bool slub_debug); /* Used for Rust formatting ('%pA') */ char *rust_fmt_argument(char *buf, char *end, const void *ptr); -- cgit v1.2.3 From 0dec7201788b9152f06321d0dab46eed93834cda Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Mon, 21 Jul 2025 16:15:57 +1000 Subject: sprintf.h requires stdarg.h In file included from drivers/crypto/intel/qat/qat_common/adf_pm_dbgfs_utils.c:4: include/linux/sprintf.h:11:54: error: unknown type name 'va_list' 11 | __printf(2, 0) int vsprintf(char *buf, const char *, va_list); | ^~~~~~~ include/linux/sprintf.h:1:1: note: 'va_list' is defined in header ''; this is probably fixable by adding '#include ' Link: https://lkml.kernel.org/r/20250721173754.42865913@canb.auug.org.au Fixes: 39ced19b9e60 ("lib/vsprintf: split out sprintf() and friends") Signed-off-by: Stephen Rothwell Cc: Andriy Shevchenko Cc: Herbert Xu Cc: Petr Mladek Cc: Steven Rostedt Cc: Rasmus Villemoes Cc: Sergey Senozhatsky Cc: Signed-off-by: Andrew Morton --- include/linux/sprintf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sprintf.h') diff --git a/include/linux/sprintf.h b/include/linux/sprintf.h index 51cab2def9ec..876130091384 100644 --- a/include/linux/sprintf.h +++ b/include/linux/sprintf.h @@ -4,6 +4,7 @@ #include #include +#include int num_to_str(char *buf, int size, unsigned long long num, unsigned int width); -- cgit v1.2.3