kernel-hardening updates for v5.19-rc1

- usercopy hardening expanded to check other allocation types
   (Matthew Wilcox, Yuanzheng Song)
 
 - arm64 stackleak behavioral improvements (Mark Rutland)
 
 - arm64 CFI code gen improvement (Sami Tolvanen)
 
 - LoadPin LSM block dev API adjustment (Christoph Hellwig)
 
 - Clang randstruct support (Bill Wendling, Kees Cook)
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Merge tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:

 - usercopy hardening expanded to check other allocation types (Matthew
   Wilcox, Yuanzheng Song)

 - arm64 stackleak behavioral improvements (Mark Rutland)

 - arm64 CFI code gen improvement (Sami Tolvanen)

 - LoadPin LSM block dev API adjustment (Christoph Hellwig)

 - Clang randstruct support (Bill Wendling, Kees Cook)

* tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (34 commits)
  loadpin: stop using bdevname
  mm: usercopy: move the virt_addr_valid() below the is_vmalloc_addr()
  gcc-plugins: randstruct: Remove cast exception handling
  af_unix: Silence randstruct GCC plugin warning
  niu: Silence randstruct warnings
  big_keys: Use struct for internal payload
  gcc-plugins: Change all version strings match kernel
  randomize_kstack: Improve docs on requirements/rationale
  lkdtm/stackleak: fix CONFIG_GCC_PLUGIN_STACKLEAK=n
  arm64: entry: use stackleak_erase_on_task_stack()
  stackleak: add on/off stack variants
  lkdtm/stackleak: check stack boundaries
  lkdtm/stackleak: prevent unexpected stack usage
  lkdtm/stackleak: rework boundary management
  lkdtm/stackleak: avoid spurious failure
  stackleak: rework poison scanning
  stackleak: rework stack high bound handling
  stackleak: clarify variable names
  stackleak: rework stack low bound handling
  stackleak: remove redundant check
  ...

Documentation/dontdiff

@@ -211,6 +211,7 @@ r200_reg_safe.h
 r300_reg_safe.h
 r420_reg_safe.h
 r600_reg_safe.h
+randstruct.seed
 randomize_layout_hash.h
 randomize_layout_seed.h
 recordmcount

Documentation/kbuild/reproducible-builds.rst

@@ -99,10 +99,10 @@ unreproducible parts can be treated as sources:
 Structure randomisation
 -----------------------
 
-If you enable ``CONFIG_GCC_PLUGIN_RANDSTRUCT``, you will need to
+If you enable ``CONFIG_RANDSTRUCT``, you will need to pre-generate
-pre-generate the random seed in
+the random seed in ``scripts/basic/randstruct.seed`` so the same
-``scripts/gcc-plugins/randomize_layout_seed.h`` so the same value
+value is used by each build. See ``scripts/gen-randstruct-seed.sh``
-is used in rebuilds.
+for details.
 
 Debug info conflicts
 --------------------

Makefile

@@ -1011,6 +1011,7 @@ include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
 include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
 include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
 include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
+include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
 include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
 
 include $(addprefix $(srctree)/, $(include-y))

arch/Kconfig

@@ -732,10 +732,7 @@ config ARCH_SUPPORTS_CFI_CLANG
 config CFI_CLANG
 	bool "Use Clang's Control Flow Integrity (CFI)"
 	depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG
-	# Clang >= 12:
+	depends on CLANG_VERSION >= 140000
-	# - https://bugs.llvm.org/show_bug.cgi?id=46258
-	# - https://bugs.llvm.org/show_bug.cgi?id=47479
-	depends on CLANG_VERSION >= 120000
 	select KALLSYMS
 	help
 	  This option enables Clang’s forward-edge Control Flow Integrity

arch/arm/vdso/Makefile

@@ -28,7 +28,7 @@ CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 CFLAGS_REMOVE_vdso.o = -pg
 
 # Force -O2 to avoid libgcc dependencies
-CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(GCC_PLUGINS_CFLAGS)
+CFLAGS_REMOVE_vgettimeofday.o = -pg -Os $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS)
 ifeq ($(c-gettimeofday-y),)
 CFLAGS_vgettimeofday.o = -O2
 else

arch/arm64/include/asm/compiler.h

@@ -23,20 +23,4 @@
 #define __builtin_return_address(val)					\
 	(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))
 
-#ifdef CONFIG_CFI_CLANG
-/*
- * With CONFIG_CFI_CLANG, the compiler replaces function address
- * references with the address of the function's CFI jump table
- * entry. The function_nocfi macro always returns the address of the
- * actual function instead.
- */
-#define function_nocfi(x) ({						\
-	void *addr;							\
-	asm("adrp %0, " __stringify(x) "\n\t"				\
-	    "add  %0, %0, :lo12:" __stringify(x)			\
-	    : "=r" (addr));						\
-	addr;								\
-})
-#endif
-
 #endif /* __ASM_COMPILER_H */

arch/arm64/include/asm/processor.h

@@ -405,12 +405,10 @@ long get_tagged_addr_ctrl(struct task_struct *task);
  * of header definitions for the use of task_stack_page.
  */
 
-#define current_top_of_stack()								\
+/*
-({											\
+ * The top of the current task's task stack
-	struct stack_info _info;							\
+ */
-	BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info));	\
+#define current_top_of_stack()	((unsigned long)current->stack + THREAD_SIZE)
-	_info.high;									\
-})
 #define on_thread_stack()	(on_task_stack(current, current_stack_pointer, 1, NULL))
 
 #endif /* __ASSEMBLY__ */

arch/arm64/kernel/entry.S

@@ -596,7 +596,7 @@ SYM_CODE_START_LOCAL(ret_to_user)
 	ldr	x19, [tsk, #TSK_TI_FLAGS]	// re-check for single-step
 	enable_step_tsk x19, x2
 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
-	bl	stackleak_erase
+	bl	stackleak_erase_on_task_stack
 #endif
 	kernel_exit 0
 SYM_CODE_END(ret_to_user)

arch/arm64/kernel/vdso/Makefile

@@ -32,7 +32,8 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
 # -Wmissing-prototypes and -Wmissing-declarations are removed from
 # the CFLAGS of vgettimeofday.c to make possible to build the
 # kernel with CONFIG_WERROR enabled.
-CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) \
+CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \
+				$(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) \
 				$(CC_FLAGS_LTO) -Wmissing-prototypes -Wmissing-declarations
 KASAN_SANITIZE			:= n
 KCSAN_SANITIZE			:= n

arch/riscv/Kconfig

@@ -468,7 +468,7 @@ config CC_HAVE_STACKPROTECTOR_TLS
 
 config STACKPROTECTOR_PER_TASK
 	def_bool y
-	depends on !GCC_PLUGIN_RANDSTRUCT
+	depends on !RANDSTRUCT
 	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
 
 config PHYS_RAM_BASE_FIXED

arch/sparc/vdso/Makefile

@@ -58,7 +58,7 @@ CFL := $(PROFILING) -mcmodel=medlow -fPIC -O2 -fasynchronous-unwind-tables -m64
 
 SPARC_REG_CFLAGS = -ffixed-g4 -ffixed-g5 -fcall-used-g5 -fcall-used-g7
 
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
 
 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -88,6 +88,7 @@ $(obj)/vdso32.so.dbg: asflags-$(CONFIG_SPARC64) += -m32
 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=medlow,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 += -m32 -msoft-float -fpic

arch/x86/entry/vdso/Makefile

@@ -91,7 +91,7 @@ ifneq ($(RETPOLINE_VDSO_CFLAGS),)
 endif
 endif
 
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
 
 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -148,6 +148,7 @@ KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))

arch/x86/include/asm/highmem.h

@@ -26,6 +26,7 @@
 #include <asm/tlbflush.h>
 #include <asm/paravirt.h>
 #include <asm/fixmap.h>
+#include <asm/pgtable_areas.h>
 
 /* declarations for highmem.c */
 extern unsigned long highstart_pfn, highend_pfn;

arch/x86/mm/pti.c

@@ -540,7 +540,7 @@ static inline bool pti_kernel_image_global_ok(void)
 	 * cases where RANDSTRUCT is in use to help keep the layout a
 	 * secret.
 	 */
-	if (IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT))
+	if (IS_ENABLED(CONFIG_RANDSTRUCT))
 		return false;
 
 	return true;

drivers/misc/lkdtm/stackleak.c

@@ -11,72 +11,125 @@
 #include "lkdtm.h"
 #include <linux/stackleak.h>
 
-void lkdtm_STACKLEAK_ERASING(void)
+#if defined(CONFIG_GCC_PLUGIN_STACKLEAK)
+/*
+ * Check that stackleak tracks the lowest stack pointer and erases the stack
+ * below this as expected.
+ *
+ * To prevent the lowest stack pointer changing during the test, IRQs are
+ * masked and instrumentation of this function is disabled. We assume that the
+ * compiler will create a fixed-size stack frame for this function.
+ *
+ * Any non-inlined function may make further use of the stack, altering the
+ * lowest stack pointer and/or clobbering poison values. To avoid spurious
+ * failures we must avoid printing until the end of the test or have already
+ * encountered a failure condition.
+ */
+static void noinstr check_stackleak_irqoff(void)
 {
-	unsigned long *sp, left, found, i;
+	const unsigned long task_stack_base = (unsigned long)task_stack_page(current);
-	const unsigned long check_depth =
+	const unsigned long task_stack_low = stackleak_task_low_bound(current);
-			STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
+	const unsigned long task_stack_high = stackleak_task_high_bound(current);
+	const unsigned long current_sp = current_stack_pointer;
+	const unsigned long lowest_sp = current->lowest_stack;
+	unsigned long untracked_high;
+	unsigned long poison_high, poison_low;
 	bool test_failed = false;
 
 	/*
-	 * For the details about the alignment of the poison values, see
+	 * Check that the current and lowest recorded stack pointer values fall
-	 * the comment in stackleak_track_stack().
+	 * within the expected task stack boundaries. These tests should never
+	 * fail unless the boundaries are incorrect or we're clobbering the
+	 * STACK_END_MAGIC, and in either casee something is seriously wrong.
 	 */
-	sp = PTR_ALIGN(&i, sizeof(unsigned long));
+	if (current_sp < task_stack_low || current_sp >= task_stack_high) {
-
+		pr_err("FAIL: current_stack_pointer (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",
-	left = ((unsigned long)sp & (THREAD_SIZE - 1)) / sizeof(unsigned long);
+		       current_sp, task_stack_low, task_stack_high - 1);
-	sp--;
+		test_failed = true;
+		goto out;
+	}
+	if (lowest_sp < task_stack_low || lowest_sp >= task_stack_high) {
+		pr_err("FAIL: current->lowest_stack (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",
+		       lowest_sp, task_stack_low, task_stack_high - 1);
+		test_failed = true;
+		goto out;
+	}
 
 	/*
-	 * One 'long int' at the bottom of the thread stack is reserved
+	 * Depending on what has run prior to this test, the lowest recorded
-	 * and not poisoned.
+	 * stack pointer could be above or below the current stack pointer.
+	 * Start from the lowest of the two.
+	 *
+	 * Poison values are naturally-aligned unsigned longs. As the current
+	 * stack pointer might not be sufficiently aligned, we must align
+	 * downwards to find the lowest known stack pointer value. This is the
+	 * high boundary for a portion of the stack which may have been used
+	 * without being tracked, and has to be scanned for poison.
 	 */
-	if (left > 1) {
+	untracked_high = min(current_sp, lowest_sp);
-		left--;
+	untracked_high = ALIGN_DOWN(untracked_high, sizeof(unsigned long));
-	} else {
-		pr_err("FAIL: not enough stack space for the test\n");
-		test_failed = true;
-		goto end;
-	}
-
-	pr_info("checking unused part of the thread stack (%lu bytes)...\n",
-					left * sizeof(unsigned long));
 
 	/*
-	 * Search for 'check_depth' poison values in a row (just like
+	 * Find the top of the poison in the same way as the erasing code.
-	 * stackleak_erase() does).
 	 */
-	for (i = 0, found = 0; i < left && found <= check_depth; i++) {
+	poison_high = stackleak_find_top_of_poison(task_stack_low, untracked_high);
-		if (*(sp - i) == STACKLEAK_POISON)
-			found++;
-		else
-			found = 0;
-	}
 
-	if (found <= check_depth) {
+	/*
-		pr_err("FAIL: the erased part is not found (checked %lu bytes)\n",
+	 * Check whether the poisoned portion of the stack (if any) consists
-						i * sizeof(unsigned long));
+	 * entirely of poison. This verifies the entries that
+	 * stackleak_find_top_of_poison() should have checked.
+	 */
+	poison_low = poison_high;
+	while (poison_low > task_stack_low) {
+		poison_low -= sizeof(unsigned long);
+
+		if (*(unsigned long *)poison_low == STACKLEAK_POISON)
+			continue;
+
+		pr_err("FAIL: non-poison value %lu bytes below poison boundary: 0x%lx\n",
+		       poison_high - poison_low, *(unsigned long *)poison_low);
 		test_failed = true;
-		goto end;
 	}
 
-	pr_info("the erased part begins after %lu not poisoned bytes\n",
+	pr_info("stackleak stack usage:\n"
-				(i - found) * sizeof(unsigned long));
+		"  high offset: %lu bytes\n"
+		"  current:     %lu bytes\n"
+		"  lowest:      %lu bytes\n"
+		"  tracked:     %lu bytes\n"
+		"  untracked:   %lu bytes\n"
+		"  poisoned:    %lu bytes\n"
+		"  low offset:  %lu bytes\n",
+		task_stack_base + THREAD_SIZE - task_stack_high,
+		task_stack_high - current_sp,
+		task_stack_high - lowest_sp,
+		task_stack_high - untracked_high,
+		untracked_high - poison_high,
+		poison_high - task_stack_low,
+		task_stack_low - task_stack_base);
 
-	/* The rest of thread stack should be erased */
+out:
-	for (; i < left; i++) {
-		if (*(sp - i) != STACKLEAK_POISON) {
-			pr_err("FAIL: bad value number %lu in the erased part: 0x%lx\n",
-								i, *(sp - i));
-			test_failed = true;
-		}
-	}
-
-end:
 	if (test_failed) {
 		pr_err("FAIL: the thread stack is NOT properly erased!\n");
-		pr_expected_config(CONFIG_GCC_PLUGIN_STACKLEAK);
 	} else {
 		pr_info("OK: the rest of the thread stack is properly erased\n");
 	}
 }
+
+void lkdtm_STACKLEAK_ERASING(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	check_stackleak_irqoff();
+	local_irq_restore(flags);
+}
+#else /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */
+void lkdtm_STACKLEAK_ERASING(void)
+{
+	if (IS_ENABLED(CONFIG_HAVE_ARCH_STACKLEAK)) {
+		pr_err("XFAIL: stackleak is not enabled (CONFIG_GCC_PLUGIN_STACKLEAK=n)\n");
+	} else {
+		pr_err("XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)\n");
+	}
+}
+#endif /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */

drivers/net/ethernet/sun/niu.c

@@ -35,6 +35,25 @@
 
 #include "niu.h"
 
+/* This driver wants to store a link to a "next page" within the
+ * page struct itself by overloading the content of the "mapping"
+ * member. This is not expected by the page API, but does currently
+ * work. However, the randstruct plugin gets very bothered by this
+ * case because "mapping" (struct address_space) is randomized, so
+ * casts to/from it trigger warnings. Hide this by way of a union,
+ * to create a typed alias of "mapping", since that's how it is
+ * actually being used here.
+ */
+union niu_page {
+	struct page page;
+	struct {
+		unsigned long __flags;	/* unused alias of "flags" */
+		struct list_head __lru;	/* unused alias of "lru" */
+		struct page *next;	/* alias of "mapping" */
+	};
+};
+#define niu_next_page(p)	container_of(p, union niu_page, page)->next
+
 #define DRV_MODULE_NAME		"niu"
 #define DRV_MODULE_VERSION	"1.1"
 #define DRV_MODULE_RELDATE	"Apr 22, 2010"
@@ -3283,7 +3302,7 @@ static struct page *niu_find_rxpage(struct rx_ring_info *rp, u64 addr,
 
 	addr &= PAGE_MASK;
 	pp = &rp->rxhash[h];
-	for (; (p = *pp) != NULL; pp = (struct page **) &p->mapping) {
+	for (; (p = *pp) != NULL; pp = &niu_next_page(p)) {
 		if (p->index == addr) {
 			*link = pp;
 			goto found;
@@ -3300,7 +3319,7 @@ static void niu_hash_page(struct rx_ring_info *rp, struct page *page, u64 base)
 	unsigned int h = niu_hash_rxaddr(rp, base);
 
 	page->index = base;
-	page->mapping = (struct address_space *) rp->rxhash[h];
+	niu_next_page(page) = rp->rxhash[h];
 	rp->rxhash[h] = page;
 }
 
@@ -3382,11 +3401,11 @@ static int niu_rx_pkt_ignore(struct niu *np, struct rx_ring_info *rp)
 		rcr_size = rp->rbr_sizes[(val & RCR_ENTRY_PKTBUFSZ) >>
 					 RCR_ENTRY_PKTBUFSZ_SHIFT];
 		if ((page->index + PAGE_SIZE) - rcr_size == addr) {
-			*link = (struct page *) page->mapping;
+			*link = niu_next_page(page);
 			np->ops->unmap_page(np->device, page->index,
 					    PAGE_SIZE, DMA_FROM_DEVICE);
 			page->index = 0;
-			page->mapping = NULL;
+			niu_next_page(page) = NULL;
 			__free_page(page);
 			rp->rbr_refill_pending++;
 		}
@@ -3451,11 +3470,11 @@ static int niu_process_rx_pkt(struct napi_struct *napi, struct niu *np,
 
 		niu_rx_skb_append(skb, page, off, append_size, rcr_size);
 		if ((page->index + rp->rbr_block_size) - rcr_size == addr) {
-			*link = (struct page *) page->mapping;
+			*link = niu_next_page(page);
 			np->ops->unmap_page(np->device, page->index,
 					    PAGE_SIZE, DMA_FROM_DEVICE);
 			page->index = 0;
-			page->mapping = NULL;
+			niu_next_page(page) = NULL;
 			rp->rbr_refill_pending++;
 		} else
 			get_page(page);
@@ -3518,13 +3537,13 @@ static void niu_rbr_free(struct niu *np, struct rx_ring_info *rp)
 
 		page = rp->rxhash[i];
 		while (page) {
-			struct page *next = (struct page *) page->mapping;
+			struct page *next = niu_next_page(page);
 			u64 base = page->index;
 
 			np->ops->unmap_page(np->device, base, PAGE_SIZE,
 					    DMA_FROM_DEVICE);
 			page->index = 0;
-			page->mapping = NULL;
+			niu_next_page(page) = NULL;
 
 			__free_page(page);
 
@@ -6440,8 +6459,7 @@ static void niu_reset_buffers(struct niu *np)
 
 				page = rp->rxhash[j];
 				while (page) {
-					struct page *next =
+					struct page *next = niu_next_page(page);
-						(struct page *) page->mapping;
 					u64 base = page->index;
 					base = base >> RBR_DESCR_ADDR_SHIFT;
 					rp->rbr[k++] = cpu_to_le32(base);
@@ -10176,6 +10194,9 @@ static int __init niu_init(void)
 
 	BUILD_BUG_ON(PAGE_SIZE < 4 * 1024);
 
+	BUILD_BUG_ON(offsetof(struct page, mapping) !=
+		     offsetof(union niu_page, next));
+
 	niu_debug = netif_msg_init(debug, NIU_MSG_DEFAULT);
 
 #ifdef CONFIG_SPARC64

include/linux/compiler-clang.h

@@ -69,6 +69,16 @@
 #define __nocfi		__attribute__((__no_sanitize__("cfi")))
 #define __cficanonical	__attribute__((__cfi_canonical_jump_table__))
 
+#if defined(CONFIG_CFI_CLANG)
+/*
+ * With CONFIG_CFI_CLANG, the compiler replaces function address
+ * references with the address of the function's CFI jump table
+ * entry. The function_nocfi macro always returns the address of the
+ * actual function instead.
+ */
+#define function_nocfi(x)	__builtin_function_start(x)
+#endif
+
 /*
  * Turn individual warnings and errors on and off locally, depending
  * on version.

include/linux/compiler-gcc.h

@@ -66,14 +66,6 @@
 		__builtin_unreachable();	\
 	} while (0)
 
-#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
-#define __randomize_layout __attribute__((randomize_layout))
-#define __no_randomize_layout __attribute__((no_randomize_layout))
-/* This anon struct can add padding, so only enable it under randstruct. */
-#define randomized_struct_fields_start	struct {
-#define randomized_struct_fields_end	} __randomize_layout;
-#endif
-
 /*
  * GCC 'asm goto' miscompiles certain code sequences:
  *

include/linux/compiler_types.h

@@ -242,15 +242,15 @@ struct ftrace_likely_data {
 # define __latent_entropy
 #endif
 
-#ifndef __randomize_layout
+#if defined(RANDSTRUCT) && !defined(__CHECKER__)
+# define __randomize_layout __designated_init __attribute__((randomize_layout))
+# define __no_randomize_layout __attribute__((no_randomize_layout))
+/* This anon struct can add padding, so only enable it under randstruct. */
+# define randomized_struct_fields_start	struct {
+# define randomized_struct_fields_end	} __randomize_layout;
+#else
 # define __randomize_layout __designated_init
-#endif
-
-#ifndef __no_randomize_layout
 # define __no_randomize_layout
-#endif
-
-#ifndef randomized_struct_fields_start
 # define randomized_struct_fields_start
 # define randomized_struct_fields_end
 #endif

include/linux/highmem-internal.h

@@ -149,6 +149,11 @@ static inline void totalhigh_pages_add(long count)
 	atomic_long_add(count, &_totalhigh_pages);
 }
 
+static inline bool is_kmap_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)x;
+	return addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP);
+}
 #else /* CONFIG_HIGHMEM */
 
 static inline struct page *kmap_to_page(void *addr)
@@ -234,6 +239,11 @@ static inline void __kunmap_atomic(void *addr)
 static inline unsigned int nr_free_highpages(void) { return 0; }
 static inline unsigned long totalhigh_pages(void) { return 0UL; }
 
+static inline bool is_kmap_addr(const void *x)
+{
+	return false;
+}
+
 #endif /* CONFIG_HIGHMEM */
 
 /*

include/linux/netfs.h

@@ -295,7 +295,7 @@ extern void netfs_stats_show(struct seq_file *);
  */
 static inline struct netfs_i_context *netfs_i_context(struct inode *inode)
 {
-	return (struct netfs_i_context *)(inode + 1);
+	return (void *)inode + sizeof(*inode);
 }
 
 /**
@@ -307,7 +307,7 @@ static inline struct netfs_i_context *netfs_i_context(struct inode *inode)
  */
 static inline struct inode *netfs_inode(struct netfs_i_context *ctx)
 {
-	return ((struct inode *)ctx) - 1;
+	return (void *)ctx - sizeof(struct inode);
 }
 
 /**

include/linux/randomize_kstack.h

@@ -40,10 +40,14 @@ DECLARE_PER_CPU(u32, kstack_offset);
  */
 #define KSTACK_OFFSET_MAX(x)	((x) & 0x3FF)
 
-/*
+/**
- * These macros must be used during syscall entry when interrupts and
+ * add_random_kstack_offset - Increase stack utilization by previously
+ *			      chosen random offset
+ *
+ * This should be used in the syscall entry path when interrupts and
  * preempt are disabled, and after user registers have been stored to
- * the stack.
+ * the stack. For testing the resulting entropy, please see:
+ * tools/testing/selftests/lkdtm/stack-entropy.sh
  */
 #define add_random_kstack_offset() do {					\
 	if (static_branch_maybe(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,	\
@@ -55,6 +59,23 @@ DECLARE_PER_CPU(u32, kstack_offset);
 	}								\
 } while (0)
 
+/**
+ * choose_random_kstack_offset - Choose the random offset for the next
+ *				 add_random_kstack_offset()
+ *
+ * This should only be used during syscall exit when interrupts and
+ * preempt are disabled. This position in the syscall flow is done to
+ * frustrate attacks from userspace attempting to learn the next offset:
+ * - Maximize the timing uncertainty visible from userspace: if the
+ *   offset is chosen at syscall entry, userspace has much more control
+ *   over the timing between choosing offsets. "How long will we be in
+ *   kernel mode?" tends to be more difficult to predict than "how long
+ *   will we be in user mode?"
+ * - Reduce the lifetime of the new offset sitting in memory during
+ *   kernel mode execution. Exposure of "thread-local" memory content
+ *   (e.g. current, percpu, etc) tends to be easier than arbitrary
+ *   location memory exposure.
+ */
 #define choose_random_kstack_offset(rand) do {				\
 	if (static_branch_maybe(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,	\
 				&randomize_kstack_offset)) {		\

include/linux/stackleak.h

@@ -15,9 +15,62 @@
 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
 #include <asm/stacktrace.h>
 
+/*
+ * The lowest address on tsk's stack which we can plausibly erase.
+ */
+static __always_inline unsigned long
+stackleak_task_low_bound(const struct task_struct *tsk)
+{
+	/*
+	 * The lowest unsigned long on the task stack contains STACK_END_MAGIC,
+	 * which we must not corrupt.
+	 */
+	return (unsigned long)end_of_stack(tsk) + sizeof(unsigned long);
+}
+
+/*
+ * The address immediately after the highest address on tsk's stack which we
+ * can plausibly erase.
+ */
+static __always_inline unsigned long
+stackleak_task_high_bound(const struct task_struct *tsk)
+{
+	/*
+	 * The task's pt_regs lives at the top of the task stack and will be
+	 * overwritten by exception entry, so there's no need to erase them.
+	 */
+	return (unsigned long)task_pt_regs(tsk);
+}
+
+/*
+ * Find the address immediately above the poisoned region of the stack, where
+ * that region falls between 'low' (inclusive) and 'high' (exclusive).
+ */
+static __always_inline unsigned long
+stackleak_find_top_of_poison(const unsigned long low, const unsigned long high)
+{
+	const unsigned int depth = STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
+	unsigned int poison_count = 0;
+	unsigned long poison_high = high;
+	unsigned long sp = high;
+
+	while (sp > low && poison_count < depth) {
+		sp -= sizeof(unsigned long);
+
+		if (*(unsigned long *)sp == STACKLEAK_POISON) {
+			poison_count++;
+		} else {
+			poison_count = 0;
+			poison_high = sp;
+		}
+	}
+
+	return poison_high;
+}
+
 static inline void stackleak_task_init(struct task_struct *t)
 {
-	t->lowest_stack = (unsigned long)end_of_stack(t) + sizeof(unsigned long);
+	t->lowest_stack = stackleak_task_low_bound(t);
 # ifdef CONFIG_STACKLEAK_METRICS
 	t->prev_lowest_stack = t->lowest_stack;
 # endif

include/linux/vermagic.h

@@ -32,11 +32,11 @@
 #else
 #define MODULE_VERMAGIC_MODVERSIONS ""
 #endif
-#ifdef RANDSTRUCT_PLUGIN
+#ifdef RANDSTRUCT
-#include <generated/randomize_layout_hash.h>
+#include <generated/randstruct_hash.h>
-#define MODULE_RANDSTRUCT_PLUGIN "RANDSTRUCT_PLUGIN_" RANDSTRUCT_HASHED_SEED
+#define MODULE_RANDSTRUCT "RANDSTRUCT_" RANDSTRUCT_HASHED_SEED
 #else
-#define MODULE_RANDSTRUCT_PLUGIN
+#define MODULE_RANDSTRUCT
 #endif
 
 #define VERMAGIC_STRING 						\
@@ -44,6 +44,6 @@
 	MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT 			\
 	MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS	\
 	MODULE_ARCH_VERMAGIC						\
-	MODULE_RANDSTRUCT_PLUGIN
+	MODULE_RANDSTRUCT
 
 #endif /* _LINUX_VERMAGIC_H */

kernel/panic.c

@@ -48,7 +48,7 @@ unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
 
 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
 static unsigned long tainted_mask =
-	IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
+	IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
 static int pause_on_oops;
 static int pause_on_oops_flag;
 static DEFINE_SPINLOCK(pause_on_oops_lock);

kernel/stackleak.c

@@ -70,59 +70,81 @@ late_initcall(stackleak_sysctls_init);
 #define skip_erasing()	false
 #endif /* CONFIG_STACKLEAK_RUNTIME_DISABLE */
 
-asmlinkage void noinstr stackleak_erase(void)
+static __always_inline void __stackleak_erase(bool on_task_stack)
 {
-	/* It would be nice not to have 'kstack_ptr' and 'boundary' on stack */
+	const unsigned long task_stack_low = stackleak_task_low_bound(current);
-	unsigned long kstack_ptr = current->lowest_stack;
+	const unsigned long task_stack_high = stackleak_task_high_bound(current);
-	unsigned long boundary = (unsigned long)end_of_stack(current);
+	unsigned long erase_low, erase_high;
-	unsigned int poison_count = 0;
-	const unsigned int depth = STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
 
-	if (skip_erasing())
+	erase_low = stackleak_find_top_of_poison(task_stack_low,
-		return;
+						 current->lowest_stack);
-
-	/* Check that 'lowest_stack' value is sane */
-	if (unlikely(kstack_ptr - boundary >= THREAD_SIZE))
-		kstack_ptr = boundary;
-
-	/* Search for the poison value in the kernel stack */
-	while (kstack_ptr > boundary && poison_count <= depth) {
-		if (*(unsigned long *)kstack_ptr == STACKLEAK_POISON)
-			poison_count++;
-		else
-			poison_count = 0;
-
-		kstack_ptr -= sizeof(unsigned long);
-	}
-
-	/*
-	 * One 'long int' at the bottom of the thread stack is reserved and
-	 * should not be poisoned (see CONFIG_SCHED_STACK_END_CHECK=y).
-	 */
-	if (kstack_ptr == boundary)
-		kstack_ptr += sizeof(unsigned long);
 
 #ifdef CONFIG_STACKLEAK_METRICS
-	current->prev_lowest_stack = kstack_ptr;
+	current->prev_lowest_stack = erase_low;
 #endif
 
 	/*
-	 * Now write the poison value to the kernel stack. Start from
+	 * Write poison to the task's stack between 'erase_low' and
-	 * 'kstack_ptr' and move up till the new 'boundary'. We assume that
+	 * 'erase_high'.
-	 * the stack pointer doesn't change when we write poison.
+	 *
+	 * If we're running on a different stack (e.g. an entry trampoline
+	 * stack) we can erase everything below the pt_regs at the top of the
+	 * task stack.
+	 *
+	 * If we're running on the task stack itself, we must not clobber any
+	 * stack used by this function and its caller. We assume that this
+	 * function has a fixed-size stack frame, and the current stack pointer
+	 * doesn't change while we write poison.
 	 */
-	if (on_thread_stack())
+	if (on_task_stack)
-		boundary = current_stack_pointer;
+		erase_high = current_stack_pointer;
 	else
-		boundary = current_top_of_stack();
+		erase_high = task_stack_high;
 
-	while (kstack_ptr < boundary) {
+	while (erase_low < erase_high) {
-		*(unsigned long *)kstack_ptr = STACKLEAK_POISON;
+		*(unsigned long *)erase_low = STACKLEAK_POISON;
-		kstack_ptr += sizeof(unsigned long);
+		erase_low += sizeof(unsigned long);
 	}
 
 	/* Reset the 'lowest_stack' value for the next syscall */
-	current->lowest_stack = current_top_of_stack() - THREAD_SIZE/64;
+	current->lowest_stack = task_stack_high;
+}
+
+/*
+ * Erase and poison the portion of the task stack used since the last erase.
+ * Can be called from the task stack or an entry stack when the task stack is
+ * no longer in use.
+ */
+asmlinkage void noinstr stackleak_erase(void)
+{
+	if (skip_erasing())
+		return;
+
+	__stackleak_erase(on_thread_stack());
+}
+
+/*
+ * Erase and poison the portion of the task stack used since the last erase.
+ * Can only be called from the task stack.
+ */
+asmlinkage void noinstr stackleak_erase_on_task_stack(void)
+{
+	if (skip_erasing())
+		return;
+
+	__stackleak_erase(true);
+}
+
+/*
+ * Erase and poison the portion of the task stack used since the last erase.
+ * Can only be called from a stack other than the task stack.
+ */
+asmlinkage void noinstr stackleak_erase_off_task_stack(void)
+{
+	if (skip_erasing())
+		return;
+
+	__stackleak_erase(false);
 }
 
 void __used __no_caller_saved_registers noinstr stackleak_track_stack(void)
@@ -139,8 +161,7 @@ void __used __no_caller_saved_registers noinstr stackleak_track_stack(void)
 	/* 'lowest_stack' should be aligned on the register width boundary */
 	sp = ALIGN(sp, sizeof(unsigned long));
 	if (sp < current->lowest_stack &&
-	    sp >= (unsigned long)task_stack_page(current) +
+	    sp >= stackleak_task_low_bound(current)) {
-						sizeof(unsigned long)) {
 		current->lowest_stack = sp;
 	}
 }

mm/usercopy.c

@@ -17,6 +17,7 @@
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
 #include <linux/thread_info.h>
+#include <linux/vmalloc.h>
 #include <linux/atomic.h>
 #include <linux/jump_label.h>
 #include <asm/sections.h>
@@ -157,91 +158,47 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n,
 		usercopy_abort("null address", NULL, to_user, ptr, n);
 }
 
-/* Checks for allocs that are marked in some way as spanning multiple pages. */
-static inline void check_page_span(const void *ptr, unsigned long n,
-				   struct page *page, bool to_user)
-{
-#ifdef CONFIG_HARDENED_USERCOPY_PAGESPAN
-	const void *end = ptr + n - 1;
-	struct page *endpage;
-	bool is_reserved, is_cma;
-
-	/*
-	 * Sometimes the kernel data regions are not marked Reserved (see
-	 * check below). And sometimes [_sdata,_edata) does not cover
-	 * rodata and/or bss, so check each range explicitly.
-	 */
-
-	/* Allow reads of kernel rodata region (if not marked as Reserved). */
-	if (ptr >= (const void *)__start_rodata &&
-	    end <= (const void *)__end_rodata) {
-		if (!to_user)
-			usercopy_abort("rodata", NULL, to_user, 0, n);
-		return;
-	}
-
-	/* Allow kernel data region (if not marked as Reserved). */
-	if (ptr >= (const void *)_sdata && end <= (const void *)_edata)
-		return;
-
-	/* Allow kernel bss region (if not marked as Reserved). */
-	if (ptr >= (const void *)__bss_start &&
-	    end <= (const void *)__bss_stop)
-		return;
-
-	/* Is the object wholly within one base page? */
-	if (likely(((unsigned long)ptr & (unsigned long)PAGE_MASK) ==
-		   ((unsigned long)end & (unsigned long)PAGE_MASK)))
-		return;
-
-	/* Allow if fully inside the same compound (__GFP_COMP) page. */
-	endpage = virt_to_head_page(end);
-	if (likely(endpage == page))
-		return;
-
-	/*
-	 * Reject if range is entirely either Reserved (i.e. special or
-	 * device memory), or CMA. Otherwise, reject since the object spans
-	 * several independently allocated pages.
-	 */
-	is_reserved = PageReserved(page);
-	is_cma = is_migrate_cma_page(page);
-	if (!is_reserved && !is_cma)
-		usercopy_abort("spans multiple pages", NULL, to_user, 0, n);
-
-	for (ptr += PAGE_SIZE; ptr <= end; ptr += PAGE_SIZE) {
-		page = virt_to_head_page(ptr);
-		if (is_reserved && !PageReserved(page))
-			usercopy_abort("spans Reserved and non-Reserved pages",
-				       NULL, to_user, 0, n);
-		if (is_cma && !is_migrate_cma_page(page))
-			usercopy_abort("spans CMA and non-CMA pages", NULL,
-				       to_user, 0, n);
-	}
-#endif
-}
-
 static inline void check_heap_object(const void *ptr, unsigned long n,
 				     bool to_user)
 {
 	struct folio *folio;
 
+	if (is_kmap_addr(ptr)) {
+		unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1);
+
+		if ((unsigned long)ptr + n - 1 > page_end)
+			usercopy_abort("kmap", NULL, to_user,
+					offset_in_page(ptr), n);
+		return;
+	}
+
+	if (is_vmalloc_addr(ptr)) {
+		struct vm_struct *area = find_vm_area(ptr);
+		unsigned long offset;
+
+		if (!area) {
+			usercopy_abort("vmalloc", "no area", to_user, 0, n);
+			return;
+		}
+
+		offset = ptr - area->addr;
+		if (offset + n > get_vm_area_size(area))
+			usercopy_abort("vmalloc", NULL, to_user, offset, n);
+		return;
+	}
+
 	if (!virt_addr_valid(ptr))
 		return;
 
-	/*
+	folio = virt_to_folio(ptr);
-	 * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the
-	 * highmem page or fallback to virt_to_page(). The following
-	 * is effectively a highmem-aware virt_to_slab().
-	 */
-	folio = page_folio(kmap_to_page((void *)ptr));
 
 	if (folio_test_slab(folio)) {
 		/* Check slab allocator for flags and size. */
 		__check_heap_object(ptr, n, folio_slab(folio), to_user);
-	} else {
+	} else if (folio_test_large(folio)) {
-		/* Verify object does not incorrectly span multiple pages. */
+		unsigned long offset = ptr - folio_address(folio);
-		check_page_span(ptr, n, folio_page(folio, 0), to_user);
+		if (offset + n > folio_size(folio))
+			usercopy_abort("page alloc", NULL, to_user, offset, n);
 	}
 }
 

net/unix/af_unix.c

@@ -1808,11 +1808,9 @@ static int maybe_init_creds(struct scm_cookie *scm,
 static bool unix_skb_scm_eq(struct sk_buff *skb,
 			    struct scm_cookie *scm)
 {
-	const struct unix_skb_parms *u = &UNIXCB(skb);
+	return UNIXCB(skb).pid == scm->pid &&
-
+	       uid_eq(UNIXCB(skb).uid, scm->creds.uid) &&
-	return u->pid == scm->pid &&
+	       gid_eq(UNIXCB(skb).gid, scm->creds.gid) &&
-	       uid_eq(u->uid, scm->creds.uid) &&
-	       gid_eq(u->gid, scm->creds.gid) &&
 	       unix_secdata_eq(scm, skb);
 }
 

scripts/Makefile.gcc-plugins

@@ -8,8 +8,6 @@ ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
 endif
 export DISABLE_LATENT_ENTROPY_PLUGIN
 
-gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV)		+= sancov_plugin.so
-
 gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)	+= structleak_plugin.so
 gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE)	\
 		+= -fplugin-arg-structleak_plugin-verbose
@@ -24,12 +22,6 @@ export DISABLE_STRUCTLEAK_PLUGIN
 gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)		\
 		+= -DSTRUCTLEAK_PLUGIN
 
-gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT)	+= randomize_layout_plugin.so
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT)		\
-		+= -DRANDSTRUCT_PLUGIN
-gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE)	\
-		+= -fplugin-arg-randomize_layout_plugin-performance-mode
-
 gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK)	+= stackleak_plugin.so
 gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK)		\
 		+= -DSTACKLEAK_PLUGIN
@@ -53,13 +45,19 @@ export DISABLE_ARM_SSP_PER_TASK_PLUGIN
 # All the plugin CFLAGS are collected here in case a build target needs to
 # filter them out of the KBUILD_CFLAGS.
 GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
-# The sancov_plugin.so is included via CFLAGS_KCOV, so it is removed here.
-GCC_PLUGINS_CFLAGS := $(filter-out %/sancov_plugin.so, $(GCC_PLUGINS_CFLAGS))
 export GCC_PLUGINS_CFLAGS
 
 # Add the flags to the build!
 KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
 
-# All enabled GCC plugins are collected here for building below.
+# Some plugins are enabled outside of this Makefile, but they still need to
-GCC_PLUGIN := $(gcc-plugin-y)
+# be included in GCC_PLUGIN so they can get built.
+gcc-plugin-external-$(CONFIG_GCC_PLUGIN_SANCOV)			\
+	+= sancov_plugin.so
+gcc-plugin-external-$(CONFIG_GCC_PLUGIN_RANDSTRUCT)		\
+	+= randomize_layout_plugin.so
+
+# All enabled GCC plugins are collected here for building in
+# scripts/gcc-scripts/Makefile.
+GCC_PLUGIN := $(gcc-plugin-y) $(gcc-plugin-external-y)
 export GCC_PLUGIN

scripts/Makefile.randstruct

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+
+randstruct-cflags-y += -DRANDSTRUCT
+
+ifdef CONFIG_GCC_PLUGIN_RANDSTRUCT
+randstruct-cflags-y	\
+	+= -fplugin=$(objtree)/scripts/gcc-plugins/randomize_layout_plugin.so
+randstruct-cflags-$(CONFIG_RANDSTRUCT_PERFORMANCE)		\
+	+= -fplugin-arg-randomize_layout_plugin-performance-mode
+else
+randstruct-cflags-y	\
+	+= -frandomize-layout-seed-file=$(objtree)/scripts/basic/randstruct.seed
+endif
+
+export RANDSTRUCT_CFLAGS := $(randstruct-cflags-y)
+
+KBUILD_CFLAGS	+= $(RANDSTRUCT_CFLAGS)

scripts/basic/.gitignore

@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 /fixdep
+/randstruct.seed

scripts/basic/Makefile

@@ -3,3 +3,14 @@
 # fixdep: used to generate dependency information during build process
 
 hostprogs-always-y	+= fixdep
+
+# randstruct: the seed is needed before building the gcc-plugin or
+# before running a Clang kernel build.
+gen-randstruct-seed	:= $(srctree)/scripts/gen-randstruct-seed.sh
+quiet_cmd_create_randstruct_seed = GENSEED $@
+cmd_create_randstruct_seed = \
+	$(CONFIG_SHELL) $(gen-randstruct-seed) \
+		$@ $(objtree)/include/generated/randstruct_hash.h
+$(obj)/randstruct.seed: $(gen-randstruct-seed) FORCE
+	$(call if_changed,create_randstruct_seed)
+always-$(CONFIG_RANDSTRUCT) += randstruct.seed

scripts/gcc-plugins/Kconfig

@@ -46,44 +46,6 @@ config GCC_PLUGIN_LATENT_ENTROPY
 	   * https://grsecurity.net/
 	   * https://pax.grsecurity.net/
 
-config GCC_PLUGIN_RANDSTRUCT
-	bool "Randomize layout of sensitive kernel structures"
-	select MODVERSIONS if MODULES
-	help
-	  If you say Y here, the layouts of structures that are entirely
-	  function pointers (and have not been manually annotated with
-	  __no_randomize_layout), or structures that have been explicitly
-	  marked with __randomize_layout, will be randomized at compile-time.
-	  This can introduce the requirement of an additional information
-	  exposure vulnerability for exploits targeting these structure
-	  types.
-
-	  Enabling this feature will introduce some performance impact,
-	  slightly increase memory usage, and prevent the use of forensic
-	  tools like Volatility against the system (unless the kernel
-	  source tree isn't cleaned after kernel installation).
-
-	  The seed used for compilation is located at
-	  scripts/gcc-plugins/randomize_layout_seed.h.  It remains after
-	  a make clean to allow for external modules to be compiled with
-	  the existing seed and will be removed by a make mrproper or
-	  make distclean.
-
-	  This plugin was ported from grsecurity/PaX. More information at:
-	   * https://grsecurity.net/
-	   * https://pax.grsecurity.net/
-
-config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
-	bool "Use cacheline-aware structure randomization"
-	depends on GCC_PLUGIN_RANDSTRUCT
-	depends on !COMPILE_TEST	# do not reduce test coverage
-	help
-	  If you say Y here, the RANDSTRUCT randomization will make a
-	  best effort at restricting randomization to cacheline-sized
-	  groups of elements.  It will further not randomize bitfields
-	  in structures.  This reduces the performance hit of RANDSTRUCT
-	  at the cost of weakened randomization.
-
 config GCC_PLUGIN_ARM_SSP_PER_TASK
 	bool
 	depends on GCC_PLUGINS && ARM

scripts/gcc-plugins/Makefile

@@ -1,12 +1,17 @@
 # SPDX-License-Identifier: GPL-2.0
 
-$(obj)/randomize_layout_plugin.so: $(objtree)/$(obj)/randomize_layout_seed.h
+$(obj)/randomize_layout_plugin.so: $(obj)/randomize_layout_seed.h
-quiet_cmd_create_randomize_layout_seed = GENSEED $@
+quiet_cmd_create_randomize_layout_seed = SEEDHDR $@
 cmd_create_randomize_layout_seed = \
-  $(CONFIG_SHELL) $(srctree)/$(src)/gen-random-seed.sh $@ $(objtree)/include/generated/randomize_layout_hash.h
+	SEED=$$(cat $(filter-out FORCE,$^) </dev/null); \
-$(objtree)/$(obj)/randomize_layout_seed.h: FORCE
+	echo '/*' > $@; \
+	echo ' * This file is automatically generated. Keep it private.' >> $@; \
+	echo ' * Exposing this value will expose the layout of randomized structures.' >> $@; \
+	echo ' */' >> $@; \
+	echo "const char *randstruct_seed = \"$$SEED\";" >> $@
+$(obj)/randomize_layout_seed.h: $(objtree)/scripts/basic/randstruct.seed FORCE
 	$(call if_changed,create_randomize_layout_seed)
-targets += randomize_layout_seed.h randomize_layout_hash.h
+targets += randomize_layout_seed.h
 
 # Build rules for plugins
 #
@@ -23,10 +28,11 @@ GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin)
 
 plugin_cxxflags	= -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \
 		  -include $(srctree)/include/linux/compiler-version.h \
-		   -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11 \
+		  -include $(objtree)/include/generated/utsrelease.h \
-		   -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \
+		  -I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11 \
-		   -ggdb -Wno-narrowing -Wno-unused-variable \
+		  -fno-rtti -fno-exceptions -fasynchronous-unwind-tables \
-		   -Wno-format-diag
+		  -ggdb -Wno-narrowing -Wno-unused-variable \
+		  -Wno-format-diag
 
 plugin_ldflags	= -shared
 

scripts/gcc-plugins/gen-random-seed.sh

@@ -1,9 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-if [ ! -f "$1" ]; then
-	SEED=`od -A n -t x8 -N 32 /dev/urandom | tr -d ' \n'`
-	echo "const char *randstruct_seed = \"$SEED\";" > "$1"
-	HASH=`echo -n "$SEED" | sha256sum | cut -d" " -f1 | tr -d ' \n'`
-	echo "#define RANDSTRUCT_HASHED_SEED \"$HASH\"" > "$2"
-fi

scripts/gcc-plugins/latent_entropy_plugin.c

@@ -82,7 +82,7 @@ __visible int plugin_is_GPL_compatible;
 static GTY(()) tree latent_entropy_decl;
 
 static struct plugin_info latent_entropy_plugin_info = {
-	.version	= "201606141920vanilla",
+	.version	= UTS_RELEASE,
 	.help		= "disable\tturn off latent entropy instrumentation\n",
 };
 

scripts/gcc-plugins/randomize_layout_plugin.c

@@ -34,29 +34,11 @@ __visible int plugin_is_GPL_compatible;
 static int performance_mode;
 
 static struct plugin_info randomize_layout_plugin_info = {
-	.version	= "201402201816vanilla",
+	.version	= UTS_RELEASE,
 	.help		= "disable\t\t\tdo not activate plugin\n"
 			  "performance-mode\tenable cacheline-aware layout randomization\n"
 };
 
-struct whitelist_entry {
-	const char *pathname;
-	const char *lhs;
-	const char *rhs;
-};
-
-static const struct whitelist_entry whitelist[] = {
-	/* NIU overloads mapping with page struct */
-	{ "drivers/net/ethernet/sun/niu.c", "page", "address_space" },
-	/* unix_skb_parms via UNIXCB() buffer */
-	{ "net/unix/af_unix.c", "unix_skb_parms", "char" },
-	/* big_key payload.data struct splashing */
-	{ "security/keys/big_key.c", "path", "void *" },
-	/* walk struct security_hook_heads as an array of struct hlist_head */
-	{ "security/security.c", "hlist_head", "security_hook_heads" },
-	{ }
-};
-
 /* from old Linux dcache.h */
 static inline unsigned long
 partial_name_hash(unsigned long c, unsigned long prevhash)
@@ -742,60 +724,6 @@ static void handle_local_var_initializers(void)
 	}
 }
 
-static bool type_name_eq(gimple stmt, const_tree type_tree, const char *wanted_name)
-{
-	const char *type_name;
-
-	if (type_tree == NULL_TREE)
-		return false;
-
-	switch (TREE_CODE(type_tree)) {
-	case RECORD_TYPE:
-		type_name = TYPE_NAME_POINTER(type_tree);
-		break;
-	case INTEGER_TYPE:
-		if (TYPE_PRECISION(type_tree) == CHAR_TYPE_SIZE)
-			type_name = "char";
-		else {
-			INFORM(gimple_location(stmt), "found non-char INTEGER_TYPE cast comparison: %qT\n", type_tree);
-			debug_tree(type_tree);
-			return false;
-		}
-		break;
-	case POINTER_TYPE:
-		if (TREE_CODE(TREE_TYPE(type_tree)) == VOID_TYPE) {
-			type_name = "void *";
-			break;
-		} else {
-			INFORM(gimple_location(stmt), "found non-void POINTER_TYPE cast comparison %qT\n", type_tree);
-			debug_tree(type_tree);
-			return false;
-		}
-	default:
-		INFORM(gimple_location(stmt), "unhandled cast comparison: %qT\n", type_tree);
-		debug_tree(type_tree);
-		return false;
-	}
-
-	return strcmp(type_name, wanted_name) == 0;
-}
-
-static bool whitelisted_cast(gimple stmt, const_tree lhs_tree, const_tree rhs_tree)
-{
-	const struct whitelist_entry *entry;
-	expanded_location xloc = expand_location(gimple_location(stmt));
-
-	for (entry = whitelist; entry->pathname; entry++) {
-		if (!strstr(xloc.file, entry->pathname))
-			continue;
-
-		if (type_name_eq(stmt, lhs_tree, entry->lhs) && type_name_eq(stmt, rhs_tree, entry->rhs))
-			return true;
-	}
-
-	return false;
-}
-
 /*
  * iterate over all statements to find "bad" casts:
  * those where the address of the start of a structure is cast
@@ -872,10 +800,7 @@ static unsigned int find_bad_casts_execute(void)
 #ifndef __DEBUG_PLUGIN
 				if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(ptr_lhs_type)))
 #endif
-				{
+				MISMATCH(gimple_location(stmt), "rhs", ptr_lhs_type, ptr_rhs_type);
-					if (!whitelisted_cast(stmt, ptr_lhs_type, ptr_rhs_type))
-						MISMATCH(gimple_location(stmt), "rhs", ptr_lhs_type, ptr_rhs_type);
-				}
 				continue;
 			}
 
@@ -898,10 +823,7 @@ static unsigned int find_bad_casts_execute(void)
 #ifndef __DEBUG_PLUGIN
 				if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(op0_type)))
 #endif
-				{
+				MISMATCH(gimple_location(stmt), "op0", ptr_lhs_type, op0_type);
-					if (!whitelisted_cast(stmt, ptr_lhs_type, op0_type))
-						MISMATCH(gimple_location(stmt), "op0", ptr_lhs_type, op0_type);
-				}
 			} else {
 				const_tree ssa_name_var = SSA_NAME_VAR(rhs1);
 				/* skip bogus type casts introduced by container_of */
@@ -911,10 +833,7 @@ static unsigned int find_bad_casts_execute(void)
 #ifndef __DEBUG_PLUGIN
 				if (lookup_attribute("randomize_performed", TYPE_ATTRIBUTES(ptr_rhs_type)))
 #endif
-				{
+				MISMATCH(gimple_location(stmt), "ssa", ptr_lhs_type, ptr_rhs_type);
-					if (!whitelisted_cast(stmt, ptr_lhs_type, ptr_rhs_type))
-						MISMATCH(gimple_location(stmt), "ssa", ptr_lhs_type, ptr_rhs_type);
-				}
 			}
 
 		}

scripts/gcc-plugins/sancov_plugin.c

@@ -26,7 +26,7 @@ __visible int plugin_is_GPL_compatible;
 tree sancov_fndecl;
 
 static struct plugin_info sancov_plugin_info = {
-	.version	= "20160402",
+	.version	= UTS_RELEASE,
 	.help		= "sancov plugin\n",
 };
 

scripts/gcc-plugins/stackleak_plugin.c

@@ -44,7 +44,7 @@ static bool verbose = false;
 static GTY(()) tree track_function_decl;
 
 static struct plugin_info stackleak_plugin_info = {
-	.version = "201707101337",
+	.version = UTS_RELEASE,
 	.help = "track-min-size=nn\ttrack stack for functions with a stack frame size >= nn bytes\n"
 		"arch=target_arch\tspecify target build arch\n"
 		"disable\t\tdo not activate the plugin\n"

scripts/gcc-plugins/structleak_plugin.c

@@ -37,7 +37,7 @@
 __visible int plugin_is_GPL_compatible;
 
 static struct plugin_info structleak_plugin_info = {
-	.version	= "20190125vanilla",
+	.version	= UTS_RELEASE,
 	.help		= "disable\tdo not activate plugin\n"
 			  "byref\tinit structs passed by reference\n"
 			  "byref-all\tinit anything passed by reference\n"

scripts/gen-randstruct-seed.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+SEED=$(od -A n -t x8 -N 32 /dev/urandom | tr -d ' \n')
+echo "$SEED" > "$1"
+HASH=$(echo -n "$SEED" | sha256sum | cut -d" " -f1)
+echo "#define RANDSTRUCT_HASHED_SEED \"$HASH\"" > "$2"

security/Kconfig

@@ -160,20 +160,9 @@ config HARDENED_USERCOPY
 	  copy_from_user() functions) by rejecting memory ranges that
 	  are larger than the specified heap object, span multiple
 	  separately allocated pages, are not on the process stack,
-	  or are part of the kernel text. This kills entire classes
+	  or are part of the kernel text. This prevents entire classes
 	  of heap overflow exploits and similar kernel memory exposures.
 
-config HARDENED_USERCOPY_PAGESPAN
-	bool "Refuse to copy allocations that span multiple pages"
-	depends on HARDENED_USERCOPY
-	depends on BROKEN
-	help
-	  When a multi-page allocation is done without __GFP_COMP,
-	  hardened usercopy will reject attempts to copy it. There are,
-	  however, several cases of this in the kernel that have not all
-	  been removed. This config is intended to be used only while
-	  trying to find such users.
-
 config FORTIFY_SOURCE
 	bool "Harden common str/mem functions against buffer overflows"
 	depends on ARCH_HAS_FORTIFY_SOURCE

security/Kconfig.hardening

@@ -266,4 +266,77 @@ config ZERO_CALL_USED_REGS
 
 endmenu
 
+config CC_HAS_RANDSTRUCT
+	def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null)
+
+choice
+	prompt "Randomize layout of sensitive kernel structures"
+	default RANDSTRUCT_FULL if COMPILE_TEST && (GCC_PLUGINS || CC_HAS_RANDSTRUCT)
+	default RANDSTRUCT_NONE
+	help
+	  If you enable this, the layouts of structures that are entirely
+	  function pointers (and have not been manually annotated with
+	  __no_randomize_layout), or structures that have been explicitly
+	  marked with __randomize_layout, will be randomized at compile-time.
+	  This can introduce the requirement of an additional information
+	  exposure vulnerability for exploits targeting these structure
+	  types.
+
+	  Enabling this feature will introduce some performance impact,
+	  slightly increase memory usage, and prevent the use of forensic
+	  tools like Volatility against the system (unless the kernel
+	  source tree isn't cleaned after kernel installation).
+
+	  The seed used for compilation is in scripts/basic/randomize.seed.
+	  It remains after a "make clean" to allow for external modules to
+	  be compiled with the existing seed and will be removed by a
+	  "make mrproper" or "make distclean". This file should not be made
+	  public, or the structure layout can be determined.
+
+	config RANDSTRUCT_NONE
+		bool "Disable structure layout randomization"
+		help
+		  Build normally: no structure layout randomization.
+
+	config RANDSTRUCT_FULL
+		bool "Fully randomize structure layout"
+		depends on CC_HAS_RANDSTRUCT || GCC_PLUGINS
+		select MODVERSIONS if MODULES
+		help
+		  Fully randomize the member layout of sensitive
+		  structures as much as possible, which may have both a
+		  memory size and performance impact.
+
+		  One difference between the Clang and GCC plugin
+		  implementations is the handling of bitfields. The GCC
+		  plugin treats them as fully separate variables,
+		  introducing sometimes significant padding. Clang tries
+		  to keep adjacent bitfields together, but with their bit
+		  ordering randomized.
+
+	config RANDSTRUCT_PERFORMANCE
+		bool "Limit randomization of structure layout to cache-lines"
+		depends on GCC_PLUGINS
+		select MODVERSIONS if MODULES
+		help
+		  Randomization of sensitive kernel structures will make a
+		  best effort at restricting randomization to cacheline-sized
+		  groups of members. It will further not randomize bitfields
+		  in structures. This reduces the performance hit of RANDSTRUCT
+		  at the cost of weakened randomization.
+endchoice
+
+config RANDSTRUCT
+	def_bool !RANDSTRUCT_NONE
+
+config GCC_PLUGIN_RANDSTRUCT
+	def_bool GCC_PLUGINS && RANDSTRUCT
+	help
+	  Use GCC plugin to randomize structure layout.
+
+	  This plugin was ported from grsecurity/PaX. More
+	  information at:
+	   * https://grsecurity.net/
+	   * https://pax.grsecurity.net/
+
 endmenu

security/keys/big_key.c

@@ -20,12 +20,13 @@
 /*
  * Layout of key payload words.
  */
-enum {
+struct big_key_payload {
-	big_key_data,
+	u8 *data;
-	big_key_path,
+	struct path path;
-	big_key_path_2nd_part,
+	size_t length;
-	big_key_len,
 };
+#define to_big_key_payload(payload)			\
+	(struct big_key_payload *)((payload).data)
 
 /*
  * If the data is under this limit, there's no point creating a shm file to
@@ -55,7 +56,7 @@ struct key_type key_type_big_key = {
  */
 int big_key_preparse(struct key_preparsed_payload *prep)
 {
-	struct path *path = (struct path *)&prep->payload.data[big_key_path];
+	struct big_key_payload *payload = to_big_key_payload(prep->payload);
 	struct file *file;
 	u8 *buf, *enckey;
 	ssize_t written;
@@ -63,13 +64,15 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 	size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE;
 	int ret;
 
+	BUILD_BUG_ON(sizeof(*payload) != sizeof(prep->payload.data));
+
 	if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data)
 		return -EINVAL;
 
 	/* Set an arbitrary quota */
 	prep->quotalen = 16;
 
-	prep->payload.data[big_key_len] = (void *)(unsigned long)datalen;
+	payload->length = datalen;
 
 	if (datalen > BIG_KEY_FILE_THRESHOLD) {
 		/* Create a shmem file to store the data in.  This will permit the data
@@ -117,9 +120,9 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 		/* Pin the mount and dentry to the key so that we can open it again
 		 * later
 		 */
-		prep->payload.data[big_key_data] = enckey;
+		payload->data = enckey;
-		*path = file->f_path;
+		payload->path = file->f_path;
-		path_get(path);
+		path_get(&payload->path);
 		fput(file);
 		kvfree_sensitive(buf, enclen);
 	} else {
@@ -129,7 +132,7 @@ int big_key_preparse(struct key_preparsed_payload *prep)
 		if (!data)
 			return -ENOMEM;
 
-		prep->payload.data[big_key_data] = data;
+		payload->data = data;
 		memcpy(data, prep->data, prep->datalen);
 	}
 	return 0;
@@ -148,12 +151,11 @@ error:
  */
 void big_key_free_preparse(struct key_preparsed_payload *prep)
 {
-	if (prep->datalen > BIG_KEY_FILE_THRESHOLD) {
+	struct big_key_payload *payload = to_big_key_payload(prep->payload);
-		struct path *path = (struct path *)&prep->payload.data[big_key_path];
 
-		path_put(path);
+	if (prep->datalen > BIG_KEY_FILE_THRESHOLD)
-	}
+		path_put(&payload->path);
-	kfree_sensitive(prep->payload.data[big_key_data]);
+	kfree_sensitive(payload->data);
 }
 
 /*
@@ -162,13 +164,12 @@ void big_key_free_preparse(struct key_preparsed_payload *prep)
  */
 void big_key_revoke(struct key *key)
 {
-	struct path *path = (struct path *)&key->payload.data[big_key_path];
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
 
 	/* clear the quota */
 	key_payload_reserve(key, 0);
-	if (key_is_positive(key) &&
+	if (key_is_positive(key) && payload->length > BIG_KEY_FILE_THRESHOLD)
-	    (size_t)key->payload.data[big_key_len] > BIG_KEY_FILE_THRESHOLD)
+		vfs_truncate(&payload->path, 0);
-		vfs_truncate(path, 0);
 }
 
 /*
@@ -176,17 +177,15 @@ void big_key_revoke(struct key *key)
  */
 void big_key_destroy(struct key *key)
 {
-	size_t datalen = (size_t)key->payload.data[big_key_len];
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
 
-	if (datalen > BIG_KEY_FILE_THRESHOLD) {
+	if (payload->length > BIG_KEY_FILE_THRESHOLD) {
-		struct path *path = (struct path *)&key->payload.data[big_key_path];
+		path_put(&payload->path);
-
+		payload->path.mnt = NULL;
-		path_put(path);
+		payload->path.dentry = NULL;
-		path->mnt = NULL;
-		path->dentry = NULL;
 	}
-	kfree_sensitive(key->payload.data[big_key_data]);
+	kfree_sensitive(payload->data);
-	key->payload.data[big_key_data] = NULL;
+	payload->data = NULL;
 }
 
 /*
@@ -211,14 +210,14 @@ int big_key_update(struct key *key, struct key_preparsed_payload *prep)
  */
 void big_key_describe(const struct key *key, struct seq_file *m)
 {
-	size_t datalen = (size_t)key->payload.data[big_key_len];
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
 
 	seq_puts(m, key->description);
 
 	if (key_is_positive(key))
 		seq_printf(m, ": %zu [%s]",
-			   datalen,
+			   payload->length,
-			   datalen > BIG_KEY_FILE_THRESHOLD ? "file" : "buff");
+			   payload->length > BIG_KEY_FILE_THRESHOLD ? "file" : "buff");
 }
 
 /*
@@ -227,16 +226,16 @@ void big_key_describe(const struct key *key, struct seq_file *m)
  */
 long big_key_read(const struct key *key, char *buffer, size_t buflen)
 {
-	size_t datalen = (size_t)key->payload.data[big_key_len];
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
+	size_t datalen = payload->length;
 	long ret;
 
 	if (!buffer || buflen < datalen)
 		return datalen;
 
 	if (datalen > BIG_KEY_FILE_THRESHOLD) {
-		struct path *path = (struct path *)&key->payload.data[big_key_path];
 		struct file *file;
-		u8 *buf, *enckey = (u8 *)key->payload.data[big_key_data];
+		u8 *buf, *enckey = payload->data;
 		size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE;
 		loff_t pos = 0;
 
@@ -244,7 +243,7 @@ long big_key_read(const struct key *key, char *buffer, size_t buflen)
 		if (!buf)
 			return -ENOMEM;
 
-		file = dentry_open(path, O_RDONLY, current_cred());
+		file = dentry_open(&payload->path, O_RDONLY, current_cred());
 		if (IS_ERR(file)) {
 			ret = PTR_ERR(file);
 			goto error;
@@ -274,7 +273,7 @@ error:
 		kvfree_sensitive(buf, enclen);
 	} else {
 		ret = datalen;
-		memcpy(buffer, key->payload.data[big_key_data], datalen);
+		memcpy(buffer, payload->data, datalen);
 	}
 
 	return ret;

security/loadpin/loadpin.c

@@ -78,11 +78,8 @@ static void check_pinning_enforcement(struct super_block *mnt_sb)
 	 * device, allow sysctl to change modes for testing.
 	 */
 	if (mnt_sb->s_bdev) {
-		char bdev[BDEVNAME_SIZE];
-
 		ro = bdev_read_only(mnt_sb->s_bdev);
-		bdevname(mnt_sb->s_bdev, bdev);
+		pr_info("%pg (%u:%u): %s\n", mnt_sb->s_bdev,
-		pr_info("%s (%u:%u): %s\n", bdev,
 			MAJOR(mnt_sb->s_bdev->bd_dev),
 			MINOR(mnt_sb->s_bdev->bd_dev),
 			ro ? "read-only" : "writable");

security/security.c

@@ -367,13 +367,12 @@ static void __init ordered_lsm_init(void)
 
 int __init early_security_init(void)
 {
-	int i;
-	struct hlist_head *list = (struct hlist_head *) &security_hook_heads;
 	struct lsm_info *lsm;
 
-	for (i = 0; i < sizeof(security_hook_heads) / sizeof(struct hlist_head);
+#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
-	     i++)
+	INIT_HLIST_HEAD(&security_hook_heads.NAME);
-		INIT_HLIST_HEAD(&list[i]);
+#include "linux/lsm_hook_defs.h"
+#undef LSM_HOOK
 
 	for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) {
 		if (!lsm->enabled)