lkml.org 
[lkml]   [2020]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] ARC: don't align ret_from_exception function
Date
ARC have a tricky implemented ret_from_exception function.
It is written on ASM and can be called like regular function.
However it has another 'entry point' as it can be called as a
continuation of EV_Trap function.

As we declare "ret_from_exception" using ENTRY macro it may align
"ret_from_exception" by 4 bytes by adding padding before it.
"ret_from_exception" doesn't require alignment by 4 bytes
(as it doesn't go to vector table, etc...) so let's avoid aligning
it by switch from ENTRY (which is alias for SYM_FUNC_START) to
SYM_FUNC_START_NOALIGN macro.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
---
arch/arc/kernel/entry-arcv2.S | 2 +-
arch/arc/kernel/entry.S | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S
index 12d5f12d10d2..d482e1507f56 100644
--- a/arch/arc/kernel/entry-arcv2.S
+++ b/arch/arc/kernel/entry-arcv2.S
@@ -260,4 +260,4 @@ debug_marker_ds:
sr r11, [AUX_IRQ_ACT]
b .Lexcept_ret

-END(ret_from_exception)
+SYM_FUNC_END(ret_from_exception)
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 60406ec62eb8..79409b518a09 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -280,7 +280,7 @@ END(EV_Trap)
;
; If ret to user mode do we need to handle signals, schedule() et al.

-ENTRY(ret_from_exception)
+SYM_FUNC_START_NOALIGN(ret_from_exception)

; Pre-{IRQ,Trap,Exception} K/U mode from pt_regs->status32
ld r8, [sp, PT_status32] ; returning to User/Kernel Mode
@@ -373,4 +373,3 @@ resume_kernel_mode:
b .Lrestore_regs

##### DONT ADD CODE HERE - .Lrestore_regs actually follows in entry-<isa>.S
-
--
2.21.1
\
 
 \ /
  Last update: 2020-03-11 17:27    [W:0.066 / U:14.500 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site