From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
To: linux-snps-arc@lists.infradead.org,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-kernel@vger.kernel.org,
Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Subject: [PATCH 2/2] ARC: don't align ret_from_exception function
Date: Wed, 11 Mar 2020 19:26:44 +0300 [thread overview]
Message-ID: <20200311162644.7667-2-Eugeniy.Paltsev@synopsys.com> (raw)
In-Reply-To: <20200311162644.7667-1-Eugeniy.Paltsev@synopsys.com>
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
next prev parent reply other threads:[~2020-03-11 16:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 16:26 [PATCH 1/2] ARC: define __ALIGN_STR and __ALIGN symbols for ARC Eugeniy Paltsev
2020-03-11 16:26 ` Eugeniy Paltsev [this message]
2020-03-11 17:38 ` [PATCH 2/2] ARC: don't align ret_from_exception function Vineet Gupta
2020-03-11 20:58 ` Eugeniy Paltsev
2020-03-11 21:10 ` Vineet Gupta
2020-03-11 22:28 ` Eugeniy Paltsev
2020-03-11 16:35 ` [PATCH 1/2] ARC: define __ALIGN_STR and __ALIGN symbols for ARC Vineet Gupta
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