Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 38fabca1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 asm updates from Ingo Molnar:
 "Two changes:

   - Remove (some) remnants of the vDSO's fake section table mechanism
     that were left behind when the vDSO build process reverted to using
     "objdump -S" to strip the userspace image.

   - Remove hardcoded POPCNT mnemonics now that the minimum binutils
     version supports the symbolic form"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Remove a stale/misleading comment from the linker script
  x86/vdso: Remove obsolete "fake section table" reservation
  x86: Use POPCNT mnemonics in arch_hweight.h
parents 8465625a 29434801

arch/x86/entry/vdso/vdso-layout.lds.S

+0 −27
Original line number Diff line number Diff line
@@ -7,16 +7,6 @@ 
 * This script controls its layout.

 */



#if defined(BUILD_VDSO64)

# define SHDR_SIZE 64

#elif defined(BUILD_VDSO32) || defined(BUILD_VDSOX32)

# define SHDR_SIZE 40

#else

# error unknown VDSO target

#endif



#define NUM_FAKE_SHDRS 13



SECTIONS

{

	/*
@@ -60,20 +50,8 @@ SECTIONS 
		*(.bss*)

		*(.dynbss*)

		*(.gnu.linkonce.b.*)



		/*

		 * Ideally this would live in a C file, but that won't

		 * work cleanly for x32 until we start building the x32

		 * C code using an x32 toolchain.

		 */

		VDSO_FAKE_SECTION_TABLE_START = .;

		. = . + NUM_FAKE_SHDRS * SHDR_SIZE;

		VDSO_FAKE_SECTION_TABLE_END = .;

	}						:text



	.fake_shstrtab	: { *(.fake_shstrtab) }		:text





	.note		: { *(.note.*) }		:text	:note



	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
@@ -87,11 +65,6 @@ SECTIONS 


	.text		: { *(.text*) }			:text	=0x90909090,



	/*

	 * At the end so that eu-elflint stays happy when vdso2c strips

	 * these.  A better implementation would avoid allocating space

	 * for these.

	 */

	.altinstructions	: { *(.altinstructions) }	:text

	.altinstr_replacement	: { *(.altinstr_replacement) }	:text

arch/x86/entry/vdso/vdso2c.c

+0 −8
Original line number Diff line number Diff line
@@ -76,8 +76,6 @@ enum { 
	sym_hpet_page,

	sym_pvclock_page,

	sym_hvclock_page,

	sym_VDSO_FAKE_SECTION_TABLE_START,

	sym_VDSO_FAKE_SECTION_TABLE_END,

};



const int special_pages[] = {
@@ -98,12 +96,6 @@ struct vdso_sym required_syms[] = { 
	[sym_hpet_page] = {"hpet_page", true},

	[sym_pvclock_page] = {"pvclock_page", true},

	[sym_hvclock_page] = {"hvclock_page", true},

	[sym_VDSO_FAKE_SECTION_TABLE_START] = {

		"VDSO_FAKE_SECTION_TABLE_START", false

	},

	[sym_VDSO_FAKE_SECTION_TABLE_END] = {

		"VDSO_FAKE_SECTION_TABLE_END", false

	},

	{"VDSO32_NOTE_MASK", true},

	{"__kernel_vsyscall", true},

	{"__kernel_sigreturn", true},

arch/x86/include/asm/arch_hweight.h

+2 −8
Original line number Diff line number Diff line
@@ -5,15 +5,9 @@ 
#include <asm/cpufeatures.h>



#ifdef CONFIG_64BIT

/* popcnt %edi, %eax */

#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc7"

/* popcnt %rdi, %rax */

#define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"

#define REG_IN "D"

#define REG_OUT "a"

#else

/* popcnt %eax, %eax */

#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"

#define REG_IN "a"

#define REG_OUT "a"

#endif
@@ -24,7 +18,7 @@ static __always_inline unsigned int __arch_hweight32(unsigned int w) 
{

	unsigned int res;



	asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)

	asm (ALTERNATIVE("call __sw_hweight32", "popcntl %1, %0", X86_FEATURE_POPCNT)

			 : "="REG_OUT (res)

			 : REG_IN (w));
@@ -52,7 +46,7 @@ static __always_inline unsigned long __arch_hweight64(__u64 w) 
{

	unsigned long res;



	asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)

	asm (ALTERNATIVE("call __sw_hweight64", "popcntq %1, %0", X86_FEATURE_POPCNT)

			 : "="REG_OUT (res)

			 : REG_IN (w));