LinuxLists.cc - [PATCH 1/3] hexagon: Handle {,SOFT}IRQENTRY

2021-05-21 09:02:12

Subject: [PATCH 1/3] hexagon: Handle {,SOFT}IRQENTRY_TEXT in linker script

Patch "mm/slub: use stackdepot to save stack trace in objects" in -mm
selects CONFIG_STACKDEPOT when CONFIG_STACKTRACE_SUPPORT is selected and
CONFIG_STACKDEPOT requires IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to be
handled after commit 505a0ef15f96 ("kasan: stackdepot: move
filter_irq_stacks() to stackdepot.c") due to the use of the
__{,soft}irqentry_text_{start,end} section symbols. If those sections
are not handled, the build is broken.

$ make ARCH=hexagon CROSS_COMPILE=hexagon-linux- LLVM=1 LLVM_IAS=1 defconfig all
...
ld.lld: error: undefined symbol: __irqentry_text_start
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a

ld.lld: error: undefined symbol: __irqentry_text_end
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a

ld.lld: error: undefined symbol: __softirqentry_text_start
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a

ld.lld: error: undefined symbol: __softirqentry_text_end
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>>> referenced by stackdepot.c
>>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
...

Add these sections to the Hexagon linker script so the build continues
to work. ld.lld's orphan section warning would have caught this prior to
the -mm commit mentioned above:

ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'

Fixes: 505a0ef15f96 ("kasan: stackdepot: move filter_irq_stacks() to stackdepot.c")
Link: https://github.com/ClangBuiltLinux/linux/issues/1381
Signed-off-by: Nathan Chancellor <[email protected]>
---
arch/hexagon/kernel/vmlinux.lds.S | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 35b18e55eae8..20f19539c5fc 100644
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -38,6 +38,8 @@ SECTIONS
.text : AT(ADDR(.text)) {
_text = .;
TEXT_TEXT
+ IRQENTRY_TEXT
+ SOFTIRQENTRY_TEXT
SCHED_TEXT
CPUIDLE_TEXT
LOCK_TEXT
--
2.32.0.rc0

2021-06-01 19:18:36

by Nick Desaulniers

[permalink] [raw]

Subject: Re: [PATCH 1/3] hexagon: Handle {,SOFT}IRQENTRY_TEXT in linker script

On Thu, May 20, 2021 at 6:13 PM Nathan Chancellor <[email protected]> wrote:
>
> Patch "mm/slub: use stackdepot to save stack trace in objects" in -mm
> selects CONFIG_STACKDEPOT when CONFIG_STACKTRACE_SUPPORT is selected and
> CONFIG_STACKDEPOT requires IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to be
> handled after commit 505a0ef15f96 ("kasan: stackdepot: move
> filter_irq_stacks() to stackdepot.c") due to the use of the
> __{,soft}irqentry_text_{start,end} section symbols. If those sections
> are not handled, the build is broken.
>
> $ make ARCH=hexagon CROSS_COMPILE=hexagon-linux- LLVM=1 LLVM_IAS=1 defconfig all
> ...
> ld.lld: error: undefined symbol: __irqentry_text_start
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>
> ld.lld: error: undefined symbol: __irqentry_text_end
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>
> ld.lld: error: undefined symbol: __softirqentry_text_start
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
>
> ld.lld: error: undefined symbol: __softirqentry_text_end
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
> ...
>
> Add these sections to the Hexagon linker script so the build continues
> to work. ld.lld's orphan section warning would have caught this prior to
> the -mm commit mentioned above:
>
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
>
> Fixes: 505a0ef15f96 ("kasan: stackdepot: move filter_irq_stacks() to stackdepot.c")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1381
> Signed-off-by: Nathan Chancellor <[email protected]>

Thanks for the series, and sorry I didn't get around to reviewing
before I took time off last week.

Reviewed-by: Nick Desaulniers <[email protected]>

> ---
> arch/hexagon/kernel/vmlinux.lds.S | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
> index 35b18e55eae8..20f19539c5fc 100644
> --- a/arch/hexagon/kernel/vmlinux.lds.S
> +++ b/arch/hexagon/kernel/vmlinux.lds.S
> @@ -38,6 +38,8 @@ SECTIONS
> .text : AT(ADDR(.text)) {
> _text = .;
> TEXT_TEXT
> + IRQENTRY_TEXT
> + SOFTIRQENTRY_TEXT
> SCHED_TEXT
> CPUIDLE_TEXT
> LOCK_TEXT
> --
> 2.32.0.rc0
>

--
Thanks,
~Nick Desaulniers

2021-06-03 17:03:46

by Brian Cain

[permalink] [raw]

Subject: RE: [PATCH 1/3] hexagon: Handle {,SOFT}IRQENTRY_TEXT in linker script

> -----Original Message-----
> From: Nathan Chancellor <[email protected]>
> Sent: Thursday, May 20, 2021 8:13 PM
> To: Brian Cain <[email protected]>; Andrew Morton <akpm@linux-
> foundation.org>
> Cc: Nick Desaulniers <[email protected]>; linux-
> [email protected]; [email protected]; clang-built-
> [email protected]; Nathan Chancellor <[email protected]>
> Subject: [PATCH 1/3] hexagon: Handle {,SOFT}IRQENTRY_TEXT in linker script
>
> Patch "mm/slub: use stackdepot to save stack trace in objects" in -mm
> selects CONFIG_STACKDEPOT when CONFIG_STACKTRACE_SUPPORT is
> selected and
> CONFIG_STACKDEPOT requires IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to
> be
> handled after commit 505a0ef15f96 ("kasan: stackdepot: move
> filter_irq_stacks() to stackdepot.c") due to the use of the
> __{,soft}irqentry_text_{start,end} section symbols. If those sections
> are not handled, the build is broken.
>
> $ make ARCH=hexagon CROSS_COMPILE=hexagon-linux- LLVM=1 LLVM_IAS=1
> defconfig all
> ...
> ld.lld: error: undefined symbol: __irqentry_text_start
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
>
> ld.lld: error: undefined symbol: __irqentry_text_end
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
>
> ld.lld: error: undefined symbol: __softirqentry_text_start
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
>
> ld.lld: error: undefined symbol: __softirqentry_text_end
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
> >>> referenced by stackdepot.c
> >>> stackdepot.o:(filter_irq_stacks) in archive
lib/built-in.a
> ...
>
> Add these sections to the Hexagon linker script so the build continues
> to work. ld.lld's orphan section warning would have caught this prior to
> the -mm commit mentioned above:
>
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is
being placed in
> '.softirqentry.text'
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is
being placed in
> '.softirqentry.text'
> ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is
being placed in
> '.softirqentry.text'
>
> Fixes: 505a0ef15f96 ("kasan: stackdepot: move filter_irq_stacks() to
> stackdepot.c")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1381
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---
> arch/hexagon/kernel/vmlinux.lds.S | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/hexagon/kernel/vmlinux.lds.S
> b/arch/hexagon/kernel/vmlinux.lds.S
> index 35b18e55eae8..20f19539c5fc 100644
> --- a/arch/hexagon/kernel/vmlinux.lds.S
> +++ b/arch/hexagon/kernel/vmlinux.lds.S
> @@ -38,6 +38,8 @@ SECTIONS
> .text : AT(ADDR(.text)) {
> _text = .;
> TEXT_TEXT
> + IRQENTRY_TEXT
> + SOFTIRQENTRY_TEXT
> SCHED_TEXT
> CPUIDLE_TEXT
> LOCK_TEXT
> --
> 2.32.0.rc0

Acked-by: Brian Cain <[email protected]>