x86/mm: Report which part of kernel image is freed (5494c3a6) · Commits · 戴 / test

The memory freeing report wasn't very useful for figuring out which parts of the kernel image were being freed. Add the details for clearer reporting in dmesg. Before: Freeing unused kernel image memory: 1348K Write protecting the kernel read-only data: 20480k Freeing unused kernel image memory: 2040K Freeing unused kernel image memory: 172K After: Freeing unused kernel image (initmem) memory: 1348K Write protecting the kernel read-only data: 20480k Freeing unused kernel image (text/rodata gap) memory: 2040K Freeing unused kernel image (rodata/data gap) memory: 172K Signed-off-by:

Kees Cook <keescook@chromium.org> Signed-off-by:

Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-28-keescook@chromium.org

arch/x86/include/asm/processor.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -958,7 +958,7 @@ static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)

		extern unsigned long arch_align_stack(unsigned long sp);
		void free_init_pages(const char *what, unsigned long begin, unsigned long end);
		extern void free_kernel_image_pages(void begin, void end);
		extern void free_kernel_image_pages(const char what, void begin, void *end);

		void default_idle(void);
		#ifdef CONFIG_XEN

arch/x86/mm/init.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -829,14 +829,13 @@ void free_init_pages(const char *what, unsigned long begin, unsigned long end)
		* 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)
		void free_kernel_image_pages(const char what, void begin, void *end)
		{
		unsigned long begin_ul = (unsigned long)begin;
		unsigned long end_ul = (unsigned long)end;
		unsigned long len_pages = (end_ul - begin_ul) >> PAGE_SHIFT;


		free_init_pages("unused kernel image", begin_ul, end_ul);
		free_init_pages(what, begin_ul, end_ul);

		/*
		* PTI maps some of the kernel into userspace. For performance,
		@@ -865,7 +864,8 @@ void __ref free_initmem(void)

		mem_encrypt_free_decrypted_mem();

		free_kernel_image_pages(&__init_begin, &__init_end);
		free_kernel_image_pages("unused kernel image (initmem)",
		&__init_begin, &__init_end);
		}

		#ifdef CONFIG_BLK_DEV_INITRD

arch/x86/mm/init_64.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1334,8 +1334,10 @@ void mark_rodata_ro(void)
		set_memory_ro(start, (end-start) >> PAGE_SHIFT);
		#endif

		free_kernel_image_pages((void )text_end, (void )rodata_start);
		free_kernel_image_pages((void )rodata_end, (void )_sdata);
		free_kernel_image_pages("unused kernel image (text/rodata gap)",
		(void )text_end, (void )rodata_start);
		free_kernel_image_pages("unused kernel image (rodata/data gap)",
		(void )rodata_end, (void )_sdata);

		debug_checkwx();
		}

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