x86/mm/init: Add helper for freeing kernel image pages

When chunks of the kernel image are freed, free_init_pages() is used directly. Consolidate the three sites that do this. Also update the string to give an incrementally better description of that memory versus what was there before. Signed-off-by: Dave Hansen <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Kees Cook <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andi Kleen <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
citral23 · Aug 5, 2018 · 6ea2738 · 6ea2738
1 parent 9f515cd
commit 6ea2738
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Showing 3 changed files with 15 additions and 5 deletions.
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
@@ -966,6 +966,7 @@ static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
 
 extern unsigned long arch_align_stack(unsigned long sp);
 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
+extern void free_kernel_image_pages(void *begin, void *end);
 
 void default_idle(void);
 #ifdef	CONFIG_XEN

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
@@ -773,13 +773,22 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 	}
 }
 
+/*
+ * begin/end can be in the direct map or the "high kernel mapping"
+ * used for the kernel image only.  free_init_pages() will do the
+ * right thing for either kind of address.
+ */
+void free_kernel_image_pages(void *begin, void *end)
+{
+	free_init_pages("unused kernel image",
+			(unsigned long)begin, (unsigned long)end);
+}
+
 void __ref free_initmem(void)
 {
 	e820__reallocate_tables();
 
-	free_init_pages("unused kernel",
-			(unsigned long)(&__init_begin),
-			(unsigned long)(&__init_end));
+	free_kernel_image_pages(&__init_begin, &__init_end);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
@@ -1283,8 +1283,8 @@ void mark_rodata_ro(void)
 	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 #endif
 
-	free_init_pages("unused kernel", text_end, rodata_start);
-	free_init_pages("unused kernel", rodata_end, _sdata);
+	free_kernel_image_pages((void *)text_end, (void *)rodata_start);
+	free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
 
 	debug_checkwx();