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-rw-r--r--arch/x86/mm/cpu_entry_area.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index b45f5aaefd74..076ebdce9bd4 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -2,6 +2,8 @@
#include <linux/spinlock.h>
#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/kcore.h>
#include <asm/cpu_entry_area.h>
#include <asm/pgtable.h>
@@ -13,6 +15,7 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page, entry_stack_storage)
#ifdef CONFIG_X86_64
static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
+static DEFINE_PER_CPU(struct kcore_list, kcore_entry_trampoline);
#endif
struct cpu_entry_area *get_cpu_entry_area(int cpu)
@@ -146,10 +149,40 @@ static void __init setup_cpu_entry_area(int cpu)
cea_set_pte(&get_cpu_entry_area(cpu)->entry_trampoline,
__pa_symbol(_entry_trampoline), PAGE_KERNEL_RX);
+ /*
+ * The cpu_entry_area alias addresses are not in the kernel binary
+ * so they do not show up in /proc/kcore normally. This adds entries
+ * for them manually.
+ */
+ kclist_add_remap(&per_cpu(kcore_entry_trampoline, cpu),
+ _entry_trampoline,
+ &get_cpu_entry_area(cpu)->entry_trampoline, PAGE_SIZE);
#endif
percpu_setup_debug_store(cpu);
}
+#ifdef CONFIG_X86_64
+int arch_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+ char *name)
+{
+ unsigned int cpu, ncpu = 0;
+
+ if (symnum >= num_possible_cpus())
+ return -EINVAL;
+
+ for_each_possible_cpu(cpu) {
+ if (ncpu++ >= symnum)
+ break;
+ }
+
+ *value = (unsigned long)&get_cpu_entry_area(cpu)->entry_trampoline;
+ *type = 't';
+ strlcpy(name, "__entry_SYSCALL_64_trampoline", KSYM_NAME_LEN);
+
+ return 0;
+}
+#endif
+
static __init void setup_cpu_entry_area_ptes(void)
{
#ifdef CONFIG_X86_32
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