diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b600df82669db000304571fd23c3af90df36190d..11e57ba2985ccd55c395a6a4c4d856fd25714721 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2192,12 +2192,6 @@
Format: 0 | 1
Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
- init_mlocked_on_free= [MM] Fill freed userspace memory with zeroes if
- it was mlock'ed and not explicitly munlock'ed
- afterwards.
- Format: 0 | 1
- Default set by CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON
-
init_pkru= [X86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9849dfda44d43ccdaaab5e5a49d979753d189f0e..9a5652c5fadd51f379118f3cdf946be4cccab049 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3776,14 +3776,7 @@ DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
static inline bool want_init_on_free(void)
{
return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
- &init_on_free);
-}
-
-DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON, init_mlocked_on_free);
-static inline bool want_init_mlocked_on_free(void)
-{
- return static_branch_maybe(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON,
- &init_mlocked_on_free);
+ &init_on_free);
}
extern bool _debug_pagealloc_enabled_early;
diff --git a/mm/internal.h b/mm/internal.h
index b2c75b12014e7fcec9cf948deae09827d37d42ba..c72c306761a48a45958c56780dee4c480b53f6a1 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -588,7 +588,6 @@ extern void __putback_isolated_page(struct page *page, unsigned int order,
extern void memblock_free_pages(struct page *page, unsigned long pfn,
unsigned int order);
extern void __free_pages_core(struct page *page, unsigned int order);
-extern void kernel_init_pages(struct page *page, int numpages);
/*
* This will have no effect, other than possibly generating a warning, if the
diff --git a/mm/memory.c b/mm/memory.c
index 0f47a533014e43efd053a7d8301615eda35d881b..2bc8032a30a2ff5d2be8db81d0b0346592953558 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1507,12 +1507,6 @@ static __always_inline void zap_present_folio_ptes(struct mmu_gather *tlb,
if (unlikely(folio_mapcount(folio) < 0))
print_bad_pte(vma, addr, ptent, page);
}
-
- if (want_init_mlocked_on_free() && folio_test_mlocked(folio) &&
- !delay_rmap && folio_test_anon(folio)) {
- kernel_init_pages(page, folio_nr_pages(folio));
- }
-
if (unlikely(__tlb_remove_folio_pages(tlb, page, nr, delay_rmap))) {
*force_flush = true;
*force_break = true;
diff --git a/mm/mm_init.c b/mm/mm_init.c
index f72b852bd5b8e3fda6fe0cc13d67be0492a676cd..3ec04933f7fd8a192d3c2681a3803ea167a39949 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2523,9 +2523,6 @@ EXPORT_SYMBOL(init_on_alloc);
DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
EXPORT_SYMBOL(init_on_free);
-DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON, init_mlocked_on_free);
-EXPORT_SYMBOL(init_mlocked_on_free);
-
static bool _init_on_alloc_enabled_early __read_mostly
= IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON);
static int __init early_init_on_alloc(char *buf)
@@ -2543,14 +2540,6 @@ static int __init early_init_on_free(char *buf)
}
early_param("init_on_free", early_init_on_free);
-static bool _init_mlocked_on_free_enabled_early __read_mostly
- = IS_ENABLED(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON);
-static int __init early_init_mlocked_on_free(char *buf)
-{
- return kstrtobool(buf, &_init_mlocked_on_free_enabled_early);
-}
-early_param("init_mlocked_on_free", early_init_mlocked_on_free);
-
DEFINE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
/*
@@ -2578,21 +2567,12 @@ static void __init mem_debugging_and_hardening_init(void)
}
#endif
- if ((_init_on_alloc_enabled_early || _init_on_free_enabled_early ||
- _init_mlocked_on_free_enabled_early) &&
+ if ((_init_on_alloc_enabled_early || _init_on_free_enabled_early) &&
page_poisoning_requested) {
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
- "will take precedence over init_on_alloc, init_on_free "
- "and init_mlocked_on_free\n");
+ "will take precedence over init_on_alloc and init_on_free\n");
_init_on_alloc_enabled_early = false;
_init_on_free_enabled_early = false;
- _init_mlocked_on_free_enabled_early = false;
- }
-
- if (_init_mlocked_on_free_enabled_early && _init_on_free_enabled_early) {
- pr_info("mem auto-init: init_on_free is on, "
- "will take precedence over init_mlocked_on_free\n");
- _init_mlocked_on_free_enabled_early = false;
}
if (_init_on_alloc_enabled_early) {
@@ -2609,17 +2589,9 @@ static void __init mem_debugging_and_hardening_init(void)
static_branch_disable(&init_on_free);
}
- if (_init_mlocked_on_free_enabled_early) {
- want_check_pages = true;
- static_branch_enable(&init_mlocked_on_free);
- } else {
- static_branch_disable(&init_mlocked_on_free);
- }
-
- if (IS_ENABLED(CONFIG_KMSAN) && (_init_on_alloc_enabled_early ||
- _init_on_free_enabled_early || _init_mlocked_on_free_enabled_early))
- pr_info("mem auto-init: please make sure init_on_alloc, init_on_free and "
- "init_mlocked_on_free are disabled when running KMSAN\n");
+ if (IS_ENABLED(CONFIG_KMSAN) &&
+ (_init_on_alloc_enabled_early || _init_on_free_enabled_early))
+ pr_info("mem auto-init: please make sure init_on_alloc and init_on_free are disabled when running KMSAN\n");
#ifdef CONFIG_DEBUG_PAGEALLOC
if (debug_pagealloc_enabled()) {
@@ -2658,10 +2630,9 @@ static void __init report_meminit(void)
else
stack = "off";
- pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s, mlocked free:%s\n",
+ pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
- want_init_on_free() ? "on" : "off",
- want_init_mlocked_on_free() ? "on" : "off");
+ want_init_on_free() ? "on" : "off");
if (want_init_on_free())
pr_info("mem auto-init: clearing system memory may take some time...\n");
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 222299b5c0e6afbe3c3785462d940243d8387a9a..7300aa9f14b0b1a70728f1219954fdd43668c88c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1016,7 +1016,7 @@ static inline bool should_skip_kasan_poison(struct page *page)
return page_kasan_tag(page) == KASAN_TAG_KERNEL;
}
-void kernel_init_pages(struct page *page, int numpages)
+static void kernel_init_pages(struct page *page, int numpages)
{
int i;
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index effbf5982be10f209be080a061358ec922a4a754..2cff851ebfd7e13b955693be9f5818ac6f8bbf03 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -255,21 +255,6 @@ config INIT_ON_FREE_DEFAULT_ON
touching "cold" memory areas. Most cases see 3-5% impact. Some
synthetic workloads have measured as high as 8%.
-config INIT_MLOCKED_ON_FREE_DEFAULT_ON
- bool "Enable mlocked memory zeroing on free"
- depends on !KMSAN
- help
- This config has the effect of setting "init_mlocked_on_free=1"
- on the kernel command line. If it is enabled, all mlocked process
- memory is zeroed when freed. This restriction to mlocked memory
- improves performance over "init_on_free" but can still be used to
- protect confidential data like key material from content exposures
- to other processes, as well as live forensics and cold boot attacks.
- Any non-mlocked memory is not cleared before it is reassigned. This
- configuration can be overwritten by setting "init_mlocked_on_free=0"
- on the command line. The "init_on_free" boot option takes
- precedence over "init_mlocked_on_free".
-
config CC_HAS_ZERO_CALL_USED_REGS
def_bool $(cc-option,-fzero-call-used-regs=used-gpr)
# https://github.com/ClangBuiltLinux/linux/issues/1766