hc
2023-12-06 08f87f769b595151be1afeff53e144f543faa614
kernel/arch/x86/include/asm/stackprotector.h
....@@ -13,7 +13,7 @@
1313 * On x86_64, %gs is shared by percpu area and stack canary. All
1414 * percpu symbols are zero based and %gs points to the base of percpu
1515 * area. The first occupant of the percpu area is always
16
- * irq_stack_union which contains stack_canary at offset 40. Userland
16
+ * fixed_percpu_data which contains stack_canary at offset 40. Userland
1717 * %gs is always saved and restored on kernel entry and exit using
1818 * swapgs, so stack protector doesn't add any complexity there.
1919 *
....@@ -65,11 +65,11 @@
6565 */
6666 static __always_inline void boot_init_stack_canary(void)
6767 {
68
- u64 uninitialized_var(canary);
68
+ u64 canary = 0;
6969 u64 tsc;
7070
7171 #ifdef CONFIG_X86_64
72
- BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40);
72
+ BUILD_BUG_ON(offsetof(struct fixed_percpu_data, stack_canary) != 40);
7373 #endif
7474 /*
7575 * We both use the random pool and the current TSC as a source
....@@ -81,7 +81,7 @@
8181 * due to locking constraints. We just leave canary
8282 * uninitialized and use the TSC based randomness on top of it.
8383 */
84
-#ifndef CONFIG_PREEMPT_RT_FULL
84
+#ifndef CONFIG_PREEMPT_RT
8585 get_random_bytes(&canary, sizeof(canary));
8686 #endif
8787 tsc = rdtsc();
....@@ -90,9 +90,18 @@
9090
9191 current->stack_canary = canary;
9292 #ifdef CONFIG_X86_64
93
- this_cpu_write(irq_stack_union.stack_canary, canary);
93
+ this_cpu_write(fixed_percpu_data.stack_canary, canary);
9494 #else
9595 this_cpu_write(stack_canary.canary, canary);
96
+#endif
97
+}
98
+
99
+static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle)
100
+{
101
+#ifdef CONFIG_X86_64
102
+ per_cpu(fixed_percpu_data.stack_canary, cpu) = idle->stack_canary;
103
+#else
104
+ per_cpu(stack_canary.canary, cpu) = idle->stack_canary;
96105 #endif
97106 }
98107
....@@ -125,6 +134,9 @@
125134 static inline void setup_stack_canary_segment(int cpu)
126135 { }
127136
137
+static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle)
138
+{ }
139
+
128140 static inline void load_stack_canary_segment(void)
129141 {
130142 #ifdef CONFIG_X86_32