stackprotector: move CANARY_MASK and get_random_canary() into stackpr…

…otector.h This has nothing to do with random.c and everything to do with stack protectors. Yes, it uses randomness. But many things use randomness. random.h and random.c are concerned with the generation of randomness, not with each and every use. So move this function into the more specific stackprotector.h file where it belongs. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
ammarfaizi2 · Oct 23, 2022 · fcc6279 · fcc6279
1 parent 14fbd1e
commit fcc6279
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Showing 7 changed files with 24 additions and 24 deletions.
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
@@ -22,9 +22,9 @@
 #include <linux/io.h>
 #include <linux/syscore_ops.h>
 #include <linux/pgtable.h>
+#include <linux/stackprotector.h>
 
 #include <asm/cmdline.h>
-#include <asm/stackprotector.h>
 #include <asm/perf_event.h>
 #include <asm/mmu_context.h>
 #include <asm/doublefault.h>

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
@@ -11,6 +11,7 @@
 #include <linux/smp.h>
 #include <linux/topology.h>
 #include <linux/pfn.h>
+#include <linux/stackprotector.h>
 #include <asm/sections.h>
 #include <asm/processor.h>
 #include <asm/desc.h>
@@ -21,7 +22,6 @@
 #include <asm/proto.h>
 #include <asm/cpumask.h>
 #include <asm/cpu.h>
-#include <asm/stackprotector.h>
 
 DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
 EXPORT_PER_CPU_SYMBOL(cpu_number);

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
@@ -56,6 +56,7 @@
 #include <linux/numa.h>
 #include <linux/pgtable.h>
 #include <linux/overflow.h>
+#include <linux/stackprotector.h>
 
 #include <asm/acpi.h>
 #include <asm/desc.h>
@@ -80,7 +81,6 @@
 #include <asm/cpu_device_id.h>
 #include <asm/spec-ctrl.h>
 #include <asm/hw_irq.h>
-#include <asm/stackprotector.h>
 #include <asm/sev.h>
 
 /* representing HT siblings of each logical CPU */

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
@@ -32,6 +32,7 @@
 #include <linux/edd.h>
 #include <linux/reboot.h>
 #include <linux/virtio_anchor.h>
+#include <linux/stackprotector.h>
 
 #include <xen/xen.h>
 #include <xen/events.h>
@@ -64,7 +65,6 @@
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include <asm/reboot.h>
-#include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
 #include <asm/mach_traps.h>
 #include <asm/mwait.h>

diff --git a/include/linux/random.h b/include/linux/random.h
@@ -115,25 +115,6 @@ static inline u32 get_random_u32_between(u32 floor, u32 ceil)
 	return floor + get_random_u32_below(ceil - floor);
 }
 
-/*
- * On 64-bit architectures, protect against non-terminated C string overflows
- * by zeroing out the first byte of the canary; this leaves 56 bits of entropy.
- */
-#ifdef CONFIG_64BIT
-# ifdef __LITTLE_ENDIAN
-#  define CANARY_MASK 0xffffffffffffff00UL
-# else /* big endian, 64 bits: */
-#  define CANARY_MASK 0x00ffffffffffffffUL
-# endif
-#else /* 32 bits: */
-# define CANARY_MASK 0xffffffffUL
-#endif
-
-static inline unsigned long get_random_canary(void)
-{
-	return get_random_long() & CANARY_MASK;
-}
-
 void __init random_init_early(const char *command_line);
 void __init random_init(void);
 bool rng_is_initialized(void);

diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h
@@ -6,6 +6,25 @@
 #include <linux/sched.h>
 #include <linux/random.h>
 
+/*
+ * On 64-bit architectures, protect against non-terminated C string overflows
+ * by zeroing out the first byte of the canary; this leaves 56 bits of entropy.
+ */
+#ifdef CONFIG_64BIT
+# ifdef __LITTLE_ENDIAN
+#  define CANARY_MASK 0xffffffffffffff00UL
+# else /* big endian, 64 bits: */
+#  define CANARY_MASK 0x00ffffffffffffffUL
+# endif
+#else /* 32 bits: */
+# define CANARY_MASK 0xffffffffUL
+#endif
+
+static inline unsigned long get_random_canary(void)
+{
+	return get_random_long() & CANARY_MASK;
+}
+
 #if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH)
 # include <asm/stackprotector.h>
 #else

diff --git a/kernel/fork.c b/kernel/fork.c
@@ -75,7 +75,6 @@
 #include <linux/freezer.h>
 #include <linux/delayacct.h>
 #include <linux/taskstats_kern.h>
-#include <linux/random.h>
 #include <linux/tty.h>
 #include <linux/fs_struct.h>
 #include <linux/magic.h>
@@ -97,6 +96,7 @@
 #include <linux/scs.h>
 #include <linux/io_uring.h>
 #include <linux/bpf.h>
+#include <linux/stackprotector.h>
 
 #include <asm/pgalloc.h>
 #include <linux/uaccess.h>