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commit 38fabca18fc4c832ea95e2d14fb1ecde8b7dcc56
parent 8465625ab4700e3e1db506ed8a541f7796356d63
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 26 Dec 2018 16:25:06 -0800

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

Diffstat:
March/x86/entry/vdso/vdso-layout.lds.S | 27---------------------------
March/x86/entry/vdso/vdso2c.c | 8--------
March/x86/include/asm/arch_hweight.h | 10++--------
3 files changed, 2 insertions(+), 43 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -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 diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c @@ -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}, diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h @@ -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));