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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-28 11:08:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-28 11:08:13 -0800
commitbcc8aff6af53907ecb60e5aa8b34fbd429408a7a (patch)
tree231702d19f95958814e0a7375b9ef7dfd10a9c97 /arch/x86/include
parent435dd727a411004d9402ad0c868c958408271a48 (diff)
parent183ef7adf4ed638ac0fb0c3c9a71fc00e8512b61 (diff)
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: "Misc updates: - Remove last remaining calls to exception_enter/exception_exit() and simplify the entry code some more. - Remove force_iret() - Add support for "Fast Short Rep Mov", which is available starting with Ice Lake Intel CPUs - and make the x86 assembly version of memmove() use REP MOV for all sizes when FSRM is available. - Micro-optimize/simplify the 32-bit boot code a bit. - Use a more future-proof SYSRET instruction mnemonic" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Simplify calculation of output address x86/entry/64: Add instruction suffix to SYSRET x86: Remove force_iret() x86/cpufeatures: Add support for fast short REP; MOVSB x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault x86/context-tracking: Remove exception_enter/exit() from do_page_fault()
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/include/asm/ptrace.h16
-rw-r--r--arch/x86/include/asm/thread_info.h9
3 files changed, 1 insertions, 25 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index e9b62498fe75..98c60fa31ced 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -357,6 +357,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 18 */
#define X86_FEATURE_AVX512_4VNNIW (18*32+ 2) /* AVX-512 Neural Network Instructions */
#define X86_FEATURE_AVX512_4FMAPS (18*32+ 3) /* AVX-512 Multiply Accumulation Single precision */
+#define X86_FEATURE_FSRM (18*32+ 4) /* Fast Short Rep Mov */
#define X86_FEATURE_AVX512_VP2INTERSECT (18*32+ 8) /* AVX-512 Intersect for D/Q */
#define X86_FEATURE_MD_CLEAR (18*32+10) /* VERW clears CPU buffers */
#define X86_FEATURE_TSX_FORCE_ABORT (18*32+13) /* "" TSX_FORCE_ABORT */
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 5057a8ed100b..78897a8da01f 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -339,22 +339,6 @@ static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
#define ARCH_HAS_USER_SINGLE_STEP_REPORT
-/*
- * When hitting ptrace_stop(), we cannot return using SYSRET because
- * that does not restore the full CPU state, only a minimal set. The
- * ptracer can change arbitrary register values, which is usually okay
- * because the usual ptrace stops run off the signal delivery path which
- * forces IRET; however, ptrace_event() stops happen in arbitrary places
- * in the kernel and don't force IRET path.
- *
- * So force IRET path after a ptrace stop.
- */
-#define arch_ptrace_stop_needed(code, info) \
-({ \
- force_iret(); \
- false; \
-})
-
struct user_desc;
extern int do_get_thread_area(struct task_struct *p, int idx,
struct user_desc __user *info);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index d779366ce3f8..cf4327986e98 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -239,15 +239,6 @@ static inline int arch_within_stack_frames(const void * const stack,
current_thread_info()->status & TS_COMPAT)
#endif
-/*
- * Force syscall return via IRET by making it look as if there was
- * some work pending. IRET is our most capable (but slowest) syscall
- * return path, which is able to restore modified SS, CS and certain
- * EFLAGS values that other (fast) syscall return instructions
- * are not able to restore properly.
- */
-#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
-
extern void arch_task_cache_init(void);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
extern void arch_release_task_struct(struct task_struct *tsk);