All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Raphael Gault <raphael.gault@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, peterz@infradead.org,
	catalin.marinas@arm.com, will.deacon@arm.com,
	julien.thierry.kdev@gmail.com, raph.gault+kdev@gmail.com
Subject: Re: [RFC v4 13/18] arm64: sleep: Prevent stack frame warnings from objtool
Date: Thu, 22 Aug 2019 15:16:20 -0500	[thread overview]
Message-ID: <20190822201620.z7eto2cfjo4uaozb@treble> (raw)
In-Reply-To: <20190816122403.14994-14-raphael.gault@arm.com>

On Fri, Aug 16, 2019 at 01:23:58PM +0100, Raphael Gault wrote:
> This code doesn't respect the Arm PCS but it is intended this
> way. Adapting it to respect the PCS would result in altering the
> behaviour.
> 
> In order to suppress objtool's warnings, we setup a stack frame
> for __cpu_suspend_enter and annotate cpu_resume and _cpu_resume
> as having non-standard stack frames.
> 
> Signed-off-by: Raphael Gault <raphael.gault@arm.com>
> ---
>  arch/arm64/kernel/sleep.S | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
> index f5b04dd8a710..55c7c099d32c 100644
> --- a/arch/arm64/kernel/sleep.S
> +++ b/arch/arm64/kernel/sleep.S
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
>  #include <linux/errno.h>
> +#include <linux/frame.h>
>  #include <linux/linkage.h>
>  #include <asm/asm-offsets.h>
>  #include <asm/assembler.h>
> @@ -90,6 +91,7 @@ ENTRY(__cpu_suspend_enter)
>  	str	x0, [x1]
>  	add	x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS
>  	stp	x29, lr, [sp, #-16]!
> +	mov	x29, sp
>  	bl	cpu_do_suspend
>  	ldp	x29, lr, [sp], #16
>  	mov	x0, #1
> @@ -146,3 +148,6 @@ ENTRY(_cpu_resume)
>  	mov	x0, #0
>  	ret
>  ENDPROC(_cpu_resume)
> +
> +	asm_stack_frame_non_standard cpu_resume
> +	asm_stack_frame_non_standard _cpu_resume

We usually put these annotations immediately after the functions they're
annotating.  And they should resemble the C macros like

  STACK_FRAME_NON_STANDARD(cpu_resume)

-- 
Josh

WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Raphael Gault <raphael.gault@arm.com>
Cc: raph.gault+kdev@gmail.com, peterz@infradead.org,
	catalin.marinas@arm.com, will.deacon@arm.com,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	julien.thierry.kdev@gmail.com
Subject: Re: [RFC v4 13/18] arm64: sleep: Prevent stack frame warnings from objtool
Date: Thu, 22 Aug 2019 15:16:20 -0500	[thread overview]
Message-ID: <20190822201620.z7eto2cfjo4uaozb@treble> (raw)
In-Reply-To: <20190816122403.14994-14-raphael.gault@arm.com>

On Fri, Aug 16, 2019 at 01:23:58PM +0100, Raphael Gault wrote:
> This code doesn't respect the Arm PCS but it is intended this
> way. Adapting it to respect the PCS would result in altering the
> behaviour.
> 
> In order to suppress objtool's warnings, we setup a stack frame
> for __cpu_suspend_enter and annotate cpu_resume and _cpu_resume
> as having non-standard stack frames.
> 
> Signed-off-by: Raphael Gault <raphael.gault@arm.com>
> ---
>  arch/arm64/kernel/sleep.S | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
> index f5b04dd8a710..55c7c099d32c 100644
> --- a/arch/arm64/kernel/sleep.S
> +++ b/arch/arm64/kernel/sleep.S
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
>  #include <linux/errno.h>
> +#include <linux/frame.h>
>  #include <linux/linkage.h>
>  #include <asm/asm-offsets.h>
>  #include <asm/assembler.h>
> @@ -90,6 +91,7 @@ ENTRY(__cpu_suspend_enter)
>  	str	x0, [x1]
>  	add	x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS
>  	stp	x29, lr, [sp, #-16]!
> +	mov	x29, sp
>  	bl	cpu_do_suspend
>  	ldp	x29, lr, [sp], #16
>  	mov	x0, #1
> @@ -146,3 +148,6 @@ ENTRY(_cpu_resume)
>  	mov	x0, #0
>  	ret
>  ENDPROC(_cpu_resume)
> +
> +	asm_stack_frame_non_standard cpu_resume
> +	asm_stack_frame_non_standard _cpu_resume

We usually put these annotations immediately after the functions they're
annotating.  And they should resemble the C macros like

  STACK_FRAME_NON_STANDARD(cpu_resume)

-- 
Josh

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-08-22 20:16 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16 12:23 [RFC v4 00/18] objtool: Add support for arm64 Raphael Gault
2019-08-16 12:23 ` Raphael Gault
2019-08-16 12:23 ` [RFC v4 01/18] objtool: Add abstraction for computation of symbols offsets Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 16:30   ` Julien
2019-08-22 16:30     ` Julien
2019-08-22 19:57   ` Josh Poimboeuf
2019-08-22 19:57     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 02/18] objtool: orc: Refactor ORC API for other architectures to implement Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 19:59   ` Josh Poimboeuf
2019-08-22 19:59     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 03/18] objtool: Move registers and control flow to arch-dependent code Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:00   ` Josh Poimboeuf
2019-08-22 20:00     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 04/18] objtool: arm64: Add required implementation for supporting the aarch64 architecture in objtool Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:00   ` Josh Poimboeuf
2019-08-22 20:00     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 05/18] objtool: special: Adapt special section handling Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:02   ` Josh Poimboeuf
2019-08-22 20:02     ` Josh Poimboeuf
2019-08-22 20:18   ` Julien
2019-08-22 20:18     ` Julien
2019-08-16 12:23 ` [RFC v4 06/18] objtool: arm64: Adapt the stack frame checks for arm architecture Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:03   ` Josh Poimboeuf
2019-08-22 20:03     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 07/18] objtool: Introduce INSN_UNKNOWN type Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:04   ` Josh Poimboeuf
2019-08-22 20:04     ` Josh Poimboeuf
2019-08-22 20:45     ` Julien
2019-08-22 20:45       ` Julien
2019-08-22 21:51       ` Josh Poimboeuf
2019-08-22 21:51         ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 08/18] objtool: Refactor switch-tables code to support other architectures Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:04   ` Josh Poimboeuf
2019-08-22 20:04     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 09/18] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:05   ` Josh Poimboeuf
2019-08-22 20:05     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 10/18] objtool: arm64: Implement functions to add switch tables alternatives Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-23 16:35   ` Julien
2019-08-23 16:35     ` Julien
2019-08-16 12:23 ` [RFC v4 11/18] arm64: alternative: Mark .altinstr_replacement as containing executable instructions Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-16 12:23 ` [RFC v4 12/18] arm64: assembler: Add macro to annotate asm function having non standard stack-frame Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:10   ` Josh Poimboeuf
2019-08-22 20:10     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 13/18] arm64: sleep: Prevent stack frame warnings from objtool Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-22 20:16   ` Josh Poimboeuf [this message]
2019-08-22 20:16     ` Josh Poimboeuf
2019-08-16 12:23 ` [RFC v4 14/18] arm64: kvm: Annotate non-standard stack frame functions Raphael Gault
2019-08-16 12:23   ` Raphael Gault
2019-08-16 12:24 ` [RFC v4 15/18] arm64: kernel: Add exception on kuser32 to prevent stack analysis Raphael Gault
2019-08-16 12:24   ` Raphael Gault
2019-08-16 12:24 ` [RFC v4 16/18] arm64: crypto: Add exceptions for crypto object " Raphael Gault
2019-08-16 12:24   ` Raphael Gault
2019-08-22 20:19   ` Josh Poimboeuf
2019-08-22 20:19     ` Josh Poimboeuf
2019-08-16 12:24 ` [RFC v4 17/18] arm64: kernel: Annotate non-standard stack frame functions Raphael Gault
2019-08-16 12:24   ` Raphael Gault
2019-08-16 12:24 ` [RFC v4 18/18] objtool: arm64: Enable stack validation for arm64 Raphael Gault
2019-08-16 12:24   ` Raphael Gault
2019-08-22 19:56 ` [RFC v4 00/18] objtool: Add support " Josh Poimboeuf
2019-08-22 19:56   ` Josh Poimboeuf
2019-08-23 12:00   ` Raphael Gault
2019-08-23 12:00     ` Raphael Gault
2019-10-14  8:37 ` Julien Thierry
2019-10-14  8:37   ` Julien Thierry
2019-10-14 13:27   ` Raphaël Gault
2019-10-14 13:27     ` Raphaël Gault

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190822201620.z7eto2cfjo4uaozb@treble \
    --to=jpoimboe@redhat.com \
    --cc=catalin.marinas@arm.com \
    --cc=julien.thierry.kdev@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=raph.gault+kdev@gmail.com \
    --cc=raphael.gault@arm.com \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.