[PATCH 5.4 01/62] x86/asm/32: Add ENDs to some functions and relabel with SYM_CODE_*

[PATCH 5.4 01/62] x86/asm/32: Add ENDs to some functions and relabel with SYM_CODE_*

[Greg Kroah-Hartman]

From: Jiri Slaby <jslaby@suse.cz>

commit 78762b0e79bc1dd01347be061abdf505202152c9 upstream.

All these are functions which are invoked from elsewhere but they are
not typical C functions. So annotate them using the new SYM_CODE_START.
All these were not balanced with any END, so mark their ends by
SYM_CODE_END, appropriately.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits]
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernate]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Len Brown <len.brown@intel.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20191011115108.12392-26-jslaby@suse.cz
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/entry/entry_32.S            | 3 ++-
 arch/x86/kernel/acpi/wakeup_32.S     | 7 ++++---
 arch/x86/kernel/ftrace_32.S          | 3 ++-
 arch/x86/kernel/head_32.S            | 3 ++-
 arch/x86/power/hibernate_asm_32.S    | 6 ++++--
 arch/x86/realmode/rm/trampoline_32.S | 6 ++++--
 arch/x86/xen/xen-asm_32.S            | 7 ++++---
 7 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 390edb7638265..bde3e0f85425f 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -869,9 +869,10 @@ GLOBAL(__begin_SYSENTER_singlestep_region)
  * Xen doesn't set %esp to be precisely what the normal SYSENTER
  * entry point expects, so fix it up before using the normal path.
  */
-ENTRY(xen_sysenter_target)
+SYM_CODE_START(xen_sysenter_target)
 	addl	$5*4, %esp			/* remove xen-provided frame */
 	jmp	.Lsysenter_past_esp
+SYM_CODE_END(xen_sysenter_target)
 #endif
 
 /*
diff --git a/arch/x86/kernel/acpi/wakeup_32.S b/arch/x86/kernel/acpi/wakeup_32.S
index e95e95960156b..5b076cb79f5fb 100644
--- a/arch/x86/kernel/acpi/wakeup_32.S
+++ b/arch/x86/kernel/acpi/wakeup_32.S
@@ -9,8 +9,7 @@
 	.code32
 	ALIGN
 
-ENTRY(wakeup_pmode_return)
-wakeup_pmode_return:
+SYM_CODE_START(wakeup_pmode_return)
 	movw	$__KERNEL_DS, %ax
 	movw	%ax, %ss
 	movw	%ax, %fs
@@ -39,6 +38,7 @@ wakeup_pmode_return:
 	# jump to place where we left off
 	movl	saved_eip, %eax
 	jmp	*%eax
+SYM_CODE_END(wakeup_pmode_return)
 
 bogus_magic:
 	jmp	bogus_magic
@@ -72,7 +72,7 @@ restore_registers:
 	popfl
 	ret
 
-ENTRY(do_suspend_lowlevel)
+SYM_CODE_START(do_suspend_lowlevel)
 	call	save_processor_state
 	call	save_registers
 	pushl	$3
@@ -87,6 +87,7 @@ ret_point:
 	call	restore_registers
 	call	restore_processor_state
 	ret
+SYM_CODE_END(do_suspend_lowlevel)
 
 .data
 ALIGN
diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index 073aab525d800..2cc0303522c99 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -89,7 +89,7 @@ WEAK(ftrace_stub)
 	ret
 END(ftrace_caller)
 
-ENTRY(ftrace_regs_caller)
+SYM_CODE_START(ftrace_regs_caller)
 	/*
 	 * We're here from an mcount/fentry CALL, and the stack frame looks like:
 	 *
@@ -163,6 +163,7 @@ GLOBAL(ftrace_regs_call)
 	popl	%eax
 
 	jmp	.Lftrace_ret
+SYM_CODE_END(ftrace_regs_caller)
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(ftrace_graph_caller)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 2e6a0676c1f43..11a5d5ade52ce 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -64,7 +64,7 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE)
  * can.
  */
 __HEAD
-ENTRY(startup_32)
+SYM_CODE_START(startup_32)
 	movl pa(initial_stack),%ecx
 	
 	/* test KEEP_SEGMENTS flag to see if the bootloader is asking
@@ -172,6 +172,7 @@ num_subarch_entries = (. - subarch_entries) / 4
 #else
 	jmp .Ldefault_entry
 #endif /* CONFIG_PARAVIRT */
+SYM_CODE_END(startup_32)
 
 #ifdef CONFIG_HOTPLUG_CPU
 /*
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 6fe383002125f..a19ed3d231853 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -35,7 +35,7 @@ ENTRY(swsusp_arch_suspend)
 	ret
 ENDPROC(swsusp_arch_suspend)
 
-ENTRY(restore_image)
+SYM_CODE_START(restore_image)
 	/* prepare to jump to the image kernel */
 	movl	restore_jump_address, %ebx
 	movl	restore_cr3, %ebp
@@ -45,9 +45,10 @@ ENTRY(restore_image)
 	/* jump to relocated restore code */
 	movl	relocated_restore_code, %eax
 	jmpl	*%eax
+SYM_CODE_END(restore_image)
 
 /* code below has been relocated to a safe page */
-ENTRY(core_restore_code)
+SYM_CODE_START(core_restore_code)
 	movl	temp_pgt, %eax
 	movl	%eax, %cr3
 
@@ -77,6 +78,7 @@ copy_loop:
 
 done:
 	jmpl	*%ebx
+SYM_CODE_END(core_restore_code)
 
 	/* code below belongs to the image kernel */
 	.align PAGE_SIZE
diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S
index 1868b158480d4..3a0ef0d577344 100644
--- a/arch/x86/realmode/rm/trampoline_32.S
+++ b/arch/x86/realmode/rm/trampoline_32.S
@@ -29,7 +29,7 @@
 	.code16
 
 	.balign	PAGE_SIZE
-ENTRY(trampoline_start)
+SYM_CODE_START(trampoline_start)
 	wbinvd			# Needed for NUMA-Q should be harmless for others
 
 	LJMPW_RM(1f)
@@ -54,11 +54,13 @@ ENTRY(trampoline_start)
 	lmsw	%dx			# into protected mode
 
 	ljmpl	$__BOOT_CS, $pa_startup_32
+SYM_CODE_END(trampoline_start)
 
 	.section ".text32","ax"
 	.code32
-ENTRY(startup_32)			# note: also used from wakeup_asm.S
+SYM_CODE_START(startup_32)			# note: also used from wakeup_asm.S
 	jmp	*%eax
+SYM_CODE_END(startup_32)
 
 	.bss
 	.balign 8
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index cd177772fe4d5..2712e91553063 100644
--- a/arch/x86/xen/xen-asm_32.S
+++ b/arch/x86/xen/xen-asm_32.S
@@ -56,7 +56,7 @@
 	_ASM_EXTABLE(1b,2b)
 .endm
 
-ENTRY(xen_iret)
+SYM_CODE_START(xen_iret)
 	/* test eflags for special cases */
 	testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)
 	jnz hyper_iret
@@ -122,6 +122,7 @@ xen_iret_end_crit:
 hyper_iret:
 	/* put this out of line since its very rarely used */
 	jmp hypercall_page + __HYPERVISOR_iret * 32
+SYM_CODE_END(xen_iret)
 
 	.globl xen_iret_start_crit, xen_iret_end_crit
 
@@ -152,7 +153,7 @@ hyper_iret:
  * The only caveat is that if the outer eax hasn't been restored yet (i.e.
  * it's still on stack), we need to restore its value here.
  */
-ENTRY(xen_iret_crit_fixup)
+SYM_CODE_START(xen_iret_crit_fixup)
 	/*
 	 * Paranoia: Make sure we're really coming from kernel space.
 	 * One could imagine a case where userspace jumps into the
@@ -179,4 +180,4 @@ ENTRY(xen_iret_crit_fixup)
 
 2:
 	ret
-END(xen_iret_crit_fixup)
+SYM_CODE_END(xen_iret_crit_fixup)
-- 
2.27.0

[PATCH 5.4 30/62] vmlinux.lds.h: Add PGO and AutoFDO input sections

[Greg Kroah-Hartman]

From: Nick Desaulniers <ndesaulniers@google.com>

commit eff8728fe69880d3f7983bec3fb6cea4c306261f upstream.

Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too.

When compiling with profiling information (collected via PGO
instrumentations or AutoFDO sampling), Clang will separate code into
.text.hot, .text.unlikely, or .text.unknown sections based on profiling
information. After D79600 (clang-11), these sections will have a
trailing `.` suffix, ie.  .text.hot., .text.unlikely., .text.unknown..

When using -ffunction-sections together with profiling infomation,
either explicitly (FGKASLR) or implicitly (LTO), code may be placed in
sections following the convention:
.text.hot.<foo>, .text.unlikely.<bar>, .text.unknown.<baz>
where <foo>, <bar>, and <baz> are functions.  (This produces one section
per function; we generally try to merge these all back via linker script
so that we don't have 50k sections).

For the above cases, we need to teach our linker scripts that such
sections might exist and that we'd explicitly like them grouped
together, otherwise we can wind up with code outside of the
_stext/_etext boundaries that might not be mapped properly for some
architectures, resulting in boot failures.

If the linker script is not told about possible input sections, then
where the section is placed as output is a heuristic-laiden mess that's
non-portable between linkers (ie. BFD and LLD), and has resulted in many
hard to debug bugs.  Kees Cook is working on cleaning this up by adding
--orphan-handling=warn linker flag used in ARCH=powerpc to additional
architectures. In the case of linker scripts, borrowing from the Zen of
Python: explicit is better than implicit.

Also, ld.bfd's internal linker script considers .text.hot AND
.text.hot.* to be part of .text, as well as .text.unlikely and
.text.unlikely.*. I didn't see support for .text.unknown.*, and didn't
see Clang producing such code in our kernel builds, but I see code in
LLVM that can produce such section names if profiling information is
missing. That may point to a larger issue with generating or collecting
profiles, but I would much rather be safe and explicit than have to
debug yet another issue related to orphan section placement.

Reported-by: Jian Cai <jiancai@google.com>
Suggested-by: Fāng-ruì Sòng <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Luis Lozano <llozano@google.com>
Tested-by: Manoj Gupta <manojgupta@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655
Link: https://reviews.llvm.org/D79600
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760
Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.org

Debugged-by: Luis Lozano <llozano@google.com>
[nc: Resolve small conflict due to lack of NOINSTR_TEXT]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/asm-generic/vmlinux.lds.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -520,7 +520,10 @@
  */
 #define TEXT_TEXT							\
 		ALIGN_FUNCTION();					\
-		*(.text.hot TEXT_MAIN .text.fixup .text.unlikely)	\
+		*(.text.hot .text.hot.*)				\
+		*(TEXT_MAIN .text.fixup)				\
+		*(.text.unlikely .text.unlikely.*)			\
+		*(.text.unknown .text.unknown.*)			\
 		*(.text..refcount)					\
 		*(.ref.text)						\
 	MEM_KEEP(init.text*)						\