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Commit 6d24c5f7 authored by Jan Beulich's avatar Jan Beulich Committed by Thomas Gleixner
Browse files

x86-64: Handle PC-relative relocations on per-CPU data 



This is in preparation of using RIP-relative addressing in many of the
per-CPU accesses.

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5458A15A0200007800044A9A@mail.emea.novell.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 2c773dd3

arch/x86/boot/compressed/misc.c

+13 −1
Original line number Diff line number Diff line
@@ -260,7 +260,7 @@ static void handle_relocations(void *output, unsigned long output_len) 


	/*

	 * Process relocations: 32 bit relocations first then 64 bit after.

	 * Two sets of binary relocations are added to the end of the kernel

	 * Three sets of binary relocations are added to the end of the kernel

	 * before compression. Each relocation table entry is the kernel

	 * address of the location which needs to be updated stored as a

	 * 32-bit value which is sign extended to 64 bits.
@@ -270,6 +270,8 @@ static void handle_relocations(void *output, unsigned long output_len) 
	 * kernel bits...

	 * 0 - zero terminator for 64 bit relocations

	 * 64 bit relocation repeated

	 * 0 - zero terminator for inverse 32 bit relocations

	 * 32 bit inverse relocation repeated

	 * 0 - zero terminator for 32 bit relocations

	 * 32 bit relocation repeated

	 *
@@ -286,6 +288,16 @@ static void handle_relocations(void *output, unsigned long output_len) 
		*(uint32_t *)ptr += delta;

	}

#ifdef CONFIG_X86_64

	while (*--reloc) {

		long extended = *reloc;

		extended += map;



		ptr = (unsigned long)extended;

		if (ptr < min_addr || ptr > max_addr)

			error("inverse 32-bit relocation outside of kernel!\n");



		*(int32_t *)ptr -= delta;

	}

	for (reloc--; *reloc; reloc--) {

		long extended = *reloc;

		extended += map;

arch/x86/tools/relocs.c

+27 −9
Original line number Diff line number Diff line
@@ -20,7 +20,10 @@ struct relocs { 


static struct relocs relocs16;

static struct relocs relocs32;

#if ELF_BITS == 64

static struct relocs relocs32neg;

static struct relocs relocs64;

#endif



struct section {

	Elf_Shdr       shdr;
@@ -762,11 +765,16 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, 


	switch (r_type) {

	case R_X86_64_NONE:

		/* NONE can be ignored. */

		break;



	case R_X86_64_PC32:

		/*

		 * NONE can be ignored and PC relative relocations don't

		 * need to be adjusted.

		 * PC relative relocations don't need to be adjusted unless

		 * referencing a percpu symbol.

		 */

		if (is_percpu_sym(sym, symname))

			add_reloc(&relocs32neg, offset);

		break;



	case R_X86_64_32:
@@ -986,7 +994,10 @@ static void emit_relocs(int as_text, int use_real_mode) 
	/* Order the relocations for more efficient processing */

	sort_relocs(&relocs16);

	sort_relocs(&relocs32);

#if ELF_BITS == 64

	sort_relocs(&relocs32neg);

	sort_relocs(&relocs64);

#endif



	/* Print the relocations */

	if (as_text) {
@@ -1007,14 +1018,21 @@ static void emit_relocs(int as_text, int use_real_mode) 
		for (i = 0; i < relocs32.count; i++)

			write_reloc(relocs32.offset[i], stdout);

	} else {

		if (ELF_BITS == 64) {

#if ELF_BITS == 64

		/* Print a stop */

		write_reloc(0, stdout);



		/* Now print each relocation */

		for (i = 0; i < relocs64.count; i++)

			write_reloc(relocs64.offset[i], stdout);

		}



		/* Print a stop */

		write_reloc(0, stdout);



		/* Now print each inverse 32-bit relocation */

		for (i = 0; i < relocs32neg.count; i++)

			write_reloc(relocs32neg.offset[i], stdout);

#endif



		/* Print a stop */

		write_reloc(0, stdout);