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

Pull x86 asm changes from Ingo Molnar:
 "There were lots of changes in this development cycle:

   - over 100 separate cleanups, restructuring changes, speedups and
     fixes in the x86 system call, irq, trap and other entry code, part
     of a heroic effort to deobfuscate a decade old spaghetti asm code
     and its C code dependencies (Denys Vlasenko, Andy Lutomirski)

   - alternatives code fixes and enhancements (Borislav Petkov)

   - simplifications and cleanups to the compat code (Brian Gerst)

   - signal handling fixes and new x86 testcases (Andy Lutomirski)

   - various other fixes and cleanups

  By their nature many of these changes are risky - we tried to test
  them well on many different x86 systems (there are no known
  regressions), and they are split up finely to help bisection - but
  there's still a fair bit of residual risk left so caveat emptor"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits)
  perf/x86/64: Report regs_user->ax too in get_regs_user()
  perf/x86/64: Simplify regs_user->abi setting code in get_regs_user()
  perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user()
  perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user()
  x86/asm/entry/32: Tidy up JNZ instructions after TESTs
  x86/asm/entry/64: Reduce padding in execve stubs
  x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
  x86/asm/entry/64: Simplify jumps in ret_from_fork
  x86/asm/entry/64: Remove a redundant jump
  x86/asm/entry/64: Optimize [v]fork/clone stubs
  x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
  x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
  x86/asm/entry/64: Use common code for rt_sigreturn() epilogue
  x86/asm/entry/64: Add forgotten CFI annotation
  x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout
  x86/asm/entry/64: Move opportunistic sysret code to syscall code path
  x86, selftests: Add sigreturn selftest
  x86/alternatives: Guard NOPs optimization
  x86/asm/entry: Clear EXTRA_REGS for all executable formats
  x86/signal: Remove pax argument from restore_sigcontext
  ...

5 files changed, 17 insertions, 7 deletions

diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
index bb1376381985..d7b1f655b3ef 100644
--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -295,7 +295,8 @@ static unsigned long find_random_addr(unsigned long minimum,
 	return slots_fetch_random();
 }
 
-unsigned char *choose_kernel_location(unsigned char *input,
+unsigned char *choose_kernel_location(struct boot_params *boot_params,
+				      unsigned char *input,
 				      unsigned long input_size,
 				      unsigned char *output,
 				      unsigned long output_size)
@@ -315,6 +316,8 @@ unsigned char *choose_kernel_location(unsigned char *input,
 	}
 #endif
 
+	boot_params->hdr.loadflags |= KASLR_FLAG;
+
 	/* Record the various known unsafe memory ranges. */
 	mem_avoid_init((unsigned long)input, input_size,
 		       (unsigned long)output, output_size);
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 1d7fbbcc196d..8ef964ddc18e 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -29,6 +29,7 @@
 #include <asm/page_types.h>
 #include <asm/boot.h>
 #include <asm/asm-offsets.h>
+#include <asm/bootparam.h>
 
 	__HEAD
 ENTRY(startup_32)
@@ -102,7 +103,7 @@ preferred_addr:
 	 * Test KEEP_SEGMENTS flag to see if the bootloader is asking
 	 * us to not reload segments
 	 */
-	testb	$(1<<6), BP_loadflags(%esi)
+	testb	$KEEP_SEGMENTS, BP_loadflags(%esi)
 	jnz	1f
 
 	cli
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 6b1766c6c082..b0c0d16ef58d 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -31,6 +31,7 @@
 #include <asm/msr.h>
 #include <asm/processor-flags.h>
 #include <asm/asm-offsets.h>
+#include <asm/bootparam.h>
 
 	__HEAD
 	.code32
@@ -46,7 +47,7 @@ ENTRY(startup_32)
 	 * Test KEEP_SEGMENTS flag to see if the bootloader is asking
 	 * us to not reload segments
 	 */
-	testb $(1<<6), BP_loadflags(%esi)
+	testb $KEEP_SEGMENTS, BP_loadflags(%esi)
 	jnz 1f
 
 	cli
@@ -164,7 +165,7 @@ ENTRY(startup_32)
 	/* After gdt is loaded */
 	xorl	%eax, %eax
 	lldt	%ax
-	movl    $0x20, %eax
+	movl    $__BOOT_TSS, %eax
 	ltr	%ax
 
 	/*
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index a950864a64da..a107b935e22f 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -377,6 +377,9 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
 
 	real_mode = rmode;
 
+	/* Clear it for solely in-kernel use */
+	real_mode->hdr.loadflags &= ~KASLR_FLAG;
+
 	sanitize_boot_params(real_mode);
 
 	if (real_mode->screen_info.orig_video_mode == 7) {
@@ -401,7 +404,7 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
 	 * the entire decompressed kernel plus relocation table, or the
 	 * entire decompressed kernel plus .bss and .brk sections.
 	 */
-	output = choose_kernel_location(input_data, input_len, output,
+	output = choose_kernel_location(real_mode, input_data, input_len, output,
 					output_len > run_size ? output_len
 							      : run_size);
 
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 04477d68403f..89dd0d78013a 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -57,7 +57,8 @@ int cmdline_find_option_bool(const char *option);
 
 #if CONFIG_RANDOMIZE_BASE
 /* aslr.c */
-unsigned char *choose_kernel_location(unsigned char *input,
+unsigned char *choose_kernel_location(struct boot_params *boot_params,
+				      unsigned char *input,
 				      unsigned long input_size,
 				      unsigned char *output,
 				      unsigned long output_size);
@@ -65,7 +66,8 @@ unsigned char *choose_kernel_location(unsigned char *input,
 bool has_cpuflag(int flag);
 #else
 static inline
-unsigned char *choose_kernel_location(unsigned char *input,
+unsigned char *choose_kernel_location(struct boot_params *boot_params,
+				      unsigned char *input,
 				      unsigned long input_size,
 				      unsigned char *output,
 				      unsigned long output_size)