[tip: x86/asm] x86/asm/entry: Annotate interrupt symbols properly

From: tip-bot2 for Jiri Slaby
Date: Fri Oct 18 2019 - 12:31:00 EST


The following commit has been merged into the x86/asm branch of tip:

Commit-ID: cc66936e504a5b91dda52fda90203e174a7a71aa
Gitweb: https://git.kernel.org/tip/cc66936e504a5b91dda52fda90203e174a7a71aa
Author: Jiri Slaby <jslaby@xxxxxxx>
AuthorDate: Fri, 11 Oct 2019 13:50:50 +02:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Fri, 18 Oct 2019 10:40:11 +02:00

x86/asm/entry: Annotate interrupt symbols properly

* annotate functions properly by SYM_CODE_START, SYM_CODE_START_LOCAL*
and SYM_CODE_END -- these are not C-like functions, so they have to
be annotated using CODE.
* use SYM_INNER_LABEL* for labels being in the middle of other functions
This prevents nested labels annotations.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20191011115108.12392-11-jslaby@xxxxxxx
---
arch/x86/entry/entry_32.S | 28 ++++++++++++++--------------
arch/x86/entry/entry_64.S | 13 ++++++-------
2 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index f83ca5a..f37ff58 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -807,8 +807,7 @@ END(ret_from_fork)
*/

# userspace resumption stub bypassing syscall exit tracing
- ALIGN
-ret_from_exception:
+SYM_CODE_START_LOCAL(ret_from_exception)
preempt_stop(CLBR_ANY)
ret_from_intr:
#ifdef CONFIG_VM86
@@ -825,13 +824,13 @@ ret_from_intr:
cmpl $USER_RPL, %eax
jb restore_all_kernel # not returning to v8086 or userspace

-ENTRY(resume_userspace)
+SYM_INNER_LABEL_ALIGN(resume_userspace, SYM_L_LOCAL)
DISABLE_INTERRUPTS(CLBR_ANY)
TRACE_IRQS_OFF
movl %esp, %eax
call prepare_exit_to_usermode
jmp restore_all
-END(ret_from_exception)
+SYM_CODE_END(ret_from_exception)

GLOBAL(__begin_SYSENTER_singlestep_region)
/*
@@ -1100,7 +1099,7 @@ restore_all_kernel:
jmp .Lirq_return

.section .fixup, "ax"
-ENTRY(iret_exc )
+SYM_CODE_START(iret_exc)
pushl $0 # no error code
pushl $do_iret_error

@@ -1117,6 +1116,7 @@ ENTRY(iret_exc )
#endif

jmp common_exception
+SYM_CODE_END(iret_exc)
.previous
_ASM_EXTABLE(.Lirq_return, iret_exc)
ENDPROC(entry_INT80_32)
@@ -1182,7 +1182,7 @@ ENTRY(spurious_entries_start)
.endr
END(spurious_entries_start)

-common_spurious:
+SYM_CODE_START_LOCAL(common_spurious)
ASM_CLAC
addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */
SAVE_ALL switch_stacks=1
@@ -1191,7 +1191,7 @@ common_spurious:
movl %esp, %eax
call smp_spurious_interrupt
jmp ret_from_intr
-ENDPROC(common_spurious)
+SYM_CODE_END(common_spurious)
#endif

/*
@@ -1199,7 +1199,7 @@ ENDPROC(common_spurious)
* so IRQ-flags tracing has to follow that:
*/
.p2align CONFIG_X86_L1_CACHE_SHIFT
-common_interrupt:
+SYM_CODE_START_LOCAL(common_interrupt)
ASM_CLAC
addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */

@@ -1209,7 +1209,7 @@ common_interrupt:
movl %esp, %eax
call do_IRQ
jmp ret_from_intr
-ENDPROC(common_interrupt)
+SYM_CODE_END(common_interrupt)

#define BUILD_INTERRUPT3(name, nr, fn) \
ENTRY(name) \
@@ -1361,7 +1361,7 @@ ENTRY(xen_hypervisor_callback)

jmp xen_iret_crit_fixup

-ENTRY(xen_do_upcall)
+SYM_INNER_LABEL_ALIGN(xen_do_upcall, SYM_L_GLOBAL)
1: mov %esp, %eax
call xen_evtchn_do_upcall
#ifndef CONFIG_PREEMPTION
@@ -1447,7 +1447,7 @@ ENTRY(page_fault)
jmp common_exception_read_cr2
END(page_fault)

-common_exception_read_cr2:
+SYM_CODE_START_LOCAL_NOALIGN(common_exception_read_cr2)
/* the function address is in %gs's slot on the stack */
SAVE_ALL switch_stacks=1 skip_gs=1

@@ -1470,9 +1470,9 @@ common_exception_read_cr2:
movl %esp, %eax # pt_regs pointer
CALL_NOSPEC %edi
jmp ret_from_exception
-END(common_exception_read_cr2)
+SYM_CODE_END(common_exception_read_cr2)

-common_exception:
+SYM_CODE_START_LOCAL_NOALIGN(common_exception)
/* the function address is in %gs's slot on the stack */
SAVE_ALL switch_stacks=1 skip_gs=1
ENCODE_FRAME_POINTER
@@ -1492,7 +1492,7 @@ common_exception:
movl %esp, %eax # pt_regs pointer
CALL_NOSPEC %edi
jmp ret_from_exception
-END(common_exception)
+SYM_CODE_END(common_exception)

ENTRY(debug)
/*
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index db43526..607e25f 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -589,18 +589,18 @@ _ASM_NOKPROBE(interrupt_entry)
* The interrupt stubs push (~vector+0x80) onto the stack and
* then jump to common_spurious/interrupt.
*/
-common_spurious:
+SYM_CODE_START_LOCAL(common_spurious)
addq $-0x80, (%rsp) /* Adjust vector to [-256, -1] range */
call interrupt_entry
UNWIND_HINT_REGS indirect=1
call smp_spurious_interrupt /* rdi points to pt_regs */
jmp ret_from_intr
-END(common_spurious)
+SYM_CODE_END(common_spurious)
_ASM_NOKPROBE(common_spurious)

/* common_interrupt is a hotpath. Align it */
.p2align CONFIG_X86_L1_CACHE_SHIFT
-common_interrupt:
+SYM_CODE_START_LOCAL(common_interrupt)
addq $-0x80, (%rsp) /* Adjust vector to [-256, -1] range */
call interrupt_entry
UNWIND_HINT_REGS indirect=1
@@ -695,7 +695,7 @@ GLOBAL(restore_regs_and_return_to_kernel)
*/
INTERRUPT_RETURN

-ENTRY(native_iret)
+SYM_INNER_LABEL_ALIGN(native_iret, SYM_L_GLOBAL)
UNWIND_HINT_IRET_REGS
/*
* Are we returning to a stack segment from the LDT? Note: in
@@ -706,8 +706,7 @@ ENTRY(native_iret)
jnz native_irq_return_ldt
#endif

-.global native_irq_return_iret
-native_irq_return_iret:
+SYM_INNER_LABEL(native_irq_return_iret, SYM_L_GLOBAL)
/*
* This may fault. Non-paranoid faults on return to userspace are
* handled by fixup_bad_iret. These include #SS, #GP, and #NP.
@@ -789,7 +788,7 @@ native_irq_return_ldt:
*/
jmp native_irq_return_iret
#endif
-END(common_interrupt)
+SYM_CODE_END(common_interrupt)
_ASM_NOKPROBE(common_interrupt)

/*