diff mbox series

reproducible builds: strip embedded file paths

Message ID 874k89kl8o.fsf@ponder
State Superseded
Headers show
Series reproducible builds: strip embedded file paths | expand

Commit Message

Vagrant Cascadian Nov. 19, 2021, 1:05 a.m. UTC 
A recent commit 12753d22563f7d2d01f2c6644c7b66b06eb5c90f introduced a
use of __FILE__ to display the file in some debugging output.

Unfortunately, the use of __FILE__ can embed the absolute build path in
the resulting binary, resulting in different binaries depending on which
path the build was performed in.

All previous versions tested in Debian built reproducibly:

  https://tests.reproducible-builds.org/debian/history/amd64/opensbi.html

The attached patch passes -ffile-prefix-map to CFLAGS in the top-level
Makefile, which should strip the top-level build path from the resulting
build. This should be supported in both gcc 8 and clang 10.

This patch was also submitted as a pull request:

  https://github.com/riscv-software-src/opensbi/pull/229


Please CC me with any concerns or questions.


Thanks!


live well,
  vagrant

Comments

Xiang W Nov. 21, 2021, 4:40 p.m. UTC | #1 
在 2021-11-18星期四的 17:05 -0800，Vagrant Cascadian写道：
> 
> Unfortunately, the use of __FILE__ can embed the absolute build path
> in
> the resulting binary, resulting in different binaries depending on
> which
> path the build was performed in.

Under what scenarios will absolute paths be embed.

Regards,
Xiang W
Jessica Clarke Nov. 21, 2021, 4:45 p.m. UTC | #2 
On 21 Nov 2021, at 16:40, Xiang W <wxjstz@126.com> wrote:
> 
> 在 2021-11-18星期四的 17:05 -0800，Vagrant Cascadian写道：
>> 
>> Unfortunately, the use of __FILE__ can embed the absolute build path
>> in
>> the resulting binary, resulting in different binaries depending on
>> which
>> path the build was performed in.
> 
> Under what scenarios will absolute paths be embed.

As Vagrant said:

"A recent commit 12753d22563f7d2d01f2c6644c7b66b06eb5c90f introduced a
use of __FILE__ to display the file in some debugging output.”

The lazy BUG macro, added in that commit, uses __FILE__.

Jess
Vagrant Cascadian Nov. 21, 2021, 7:20 p.m. UTC | #3 
On 2021-11-22, Xiang W. wrote:
> 在 2021-11-18星期四的 17:05 -0800，Vagrant Cascadian写道：
>> 
>> Unfortunately, the use of __FILE__ can embed the absolute build path
>> in
>> the resulting binary, resulting in different binaries depending on
>> which
>> path the build was performed in.
>
> Under what scenarios will absolute paths be embed.

In each of the directories below, I built using the same toolchain from
the same git commit...

$ cd /home/vagrant/src/opensbi/opensbi1
$ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n PLATFORM=generic
...
$ strings build/platform/generic/firmware/fw_dynamic.bin | grep /home/vagrant
/home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c

$ cd /home/vagrant/src/opensbi/opensbi2
$ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n PLATFORM=generic
...
$ strings build/platform/generic/firmware/fw_dynamic.bin | grep /home/vagrant
/home/vagrant/src/opensbi/opensbi2/lib/sbi/riscv_asm.c


With the patch applied:

$ cd /home/vagrant/src/opensbi/opensbi3
$ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n PLATFORM=generic
...
$ strings build/platform/generic/firmware/fw_dynamic.bin  | grep /home/vagrant
$ strings build/platform/generic/firmware/fw_dynamic.bin  | grep riscv_asm.c
./lib/sbi/riscv_asm.c

A relative path within the source should be sufficient for the debug
message to properly identify the relevent source files...


An alternate approach would be to not use __FILE__ at all, but that
would probably take more code than passing -ffile-prefix-map at compile
time.


Thanks!


live well,
  vagrant
Xiang W Nov. 22, 2021, 1:45 a.m. UTC | #4 
在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
> of the directories below, I built using the same toolchain from
> the same git commit...
> 
> $ cd /home/vagrant/src/opensbi/opensbi1
> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> PLATFORM=generic
> ...
> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> /home/vagrant
> /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
> 
> $ cd /home/vagrant/src/opensbi/opensbi2
> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> PLATFORM=generic
> ...
> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> /home/vagrant
> /home/vagrant/src/opensbi/opensbi2/lib/sbi/riscv_asm.c
> 
> 
> With the patch applied:
> 
> $ cd /home/vagrant/src/opensbi/opensbi3
This is because the source file uses the absolute path when compiling,
you can use the relative path by modifying the Makefile

diff --git a/Makefile b/Makefile
index 8623c1c..d017534 100644
--- a/Makefile
+++ b/Makefile
@@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p `dirname
$(1)`; \
 	       -MM $(2) >> $(1) || rm -f $(1)
 compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 	     echo " CC        $(subst $(build_dir)/,,$(1))"; \
-	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c $(2) -
o $(1)
+	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
$(subst $(src_dir)/,,$(2)) -o $(1)
 compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 	     echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
 	     printf %s `dirname $(1)`/ > $(1) && \

Regards,
Xiang W
Vagrant Cascadian Nov. 22, 2021, 3:59 a.m. UTC | #5 
On 2021-11-22, Xiang W. wrote:
> 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
>> of the directories below, I built using the same toolchain from
>> the same git commit...
>> 
>> $ cd /home/vagrant/src/opensbi/opensbi1
>> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
>> PLATFORM=generic
>> ...
>> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
>> /home/vagrant
>> /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
...
> This is because the source file uses the absolute path when compiling,
> you can use the relative path by modifying the Makefile
>
> diff --git a/Makefile b/Makefile
> index 8623c1c..d017534 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p `dirname
> $(1)`; \
>  	       -MM $(2) >> $(1) || rm -f $(1)
>  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
>  	     echo " CC        $(subst $(build_dir)/,,$(1))"; \
> -	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c $(2) -
> o $(1)
> +	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> $(subst $(src_dir)/,,$(2)) -o $(1)
>  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
>  	     echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
>  	     printf %s `dirname $(1)`/ > $(1) && \

That solves the issue and is probably better than passing more compiler
arguments, thanks!


live well,
  vagrant
Anup Patel Nov. 22, 2021, 4:43 a.m. UTC | #6 
On Mon, Nov 22, 2021 at 10:02 AM Vagrant Cascadian
<vagrant@reproducible-builds.org> wrote:
>
> On 2021-11-22, Xiang W. wrote:
> > 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
> >> of the directories below, I built using the same toolchain from
> >> the same git commit...
> >>
> >> $ cd /home/vagrant/src/opensbi/opensbi1
> >> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> >> PLATFORM=generic
> >> ...
> >> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> >> /home/vagrant
> >> /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
> ...
> > This is because the source file uses the absolute path when compiling,
> > you can use the relative path by modifying the Makefile
> >
> > diff --git a/Makefile b/Makefile
> > index 8623c1c..d017534 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p `dirname
> > $(1)`; \
> >              -MM $(2) >> $(1) || rm -f $(1)
> >  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> >            echo " CC        $(subst $(build_dir)/,,$(1))"; \
> > -          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c $(2) -
> > o $(1)
> > +          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> > $(subst $(src_dir)/,,$(2)) -o $(1)
> >  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> >            echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
> >            printf %s `dirname $(1)`/ > $(1) && \
>
> That solves the issue and is probably better than passing more compiler
> arguments, thanks!

This will only work if we are compiling from the OpenSBI source directory
itself. What if users compile OpenSBI with a different current directory
using "make -C <opensbi_source_path>". I guess passing compiler
argument will allow "make -C <opensbi_source_path>".

Regards,
Anup

>
>
> live well,
>   vagrant
> --
> opensbi mailing list
> opensbi@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi
Xiang W Nov. 22, 2021, 5:44 a.m. UTC | #7 
在 2021-11-22星期一的 10:13 +0530，Anup Patel写道：
> On Mon, Nov 22, 2021 at 10:02 AM Vagrant Cascadian
> <vagrant@reproducible-builds.org> wrote:
> > 
> > On 2021-11-22, Xiang W. wrote:
> > > 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
> > > > of the directories below, I built using the same toolchain from
> > > > the same git commit...
> > > > 
> > > > $ cd /home/vagrant/src/opensbi/opensbi1
> > > > $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> > > > PLATFORM=generic
> > > > ...
> > > > $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> > > > /home/vagrant
> > > > /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
> > ...
> > > This is because the source file uses the absolute path when
> > > compiling,
> > > you can use the relative path by modifying the Makefile
> > > 
> > > diff --git a/Makefile b/Makefile
> > > index 8623c1c..d017534 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p
> > > `dirname
> > > $(1)`; \
> > >              -MM $(2) >> $(1) || rm -f $(1)
> > >  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > >            echo " CC        $(subst $(build_dir)/,,$(1))"; \
> > > -          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> > > $(2) -
> > > o $(1)
> > > +          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> > > $(subst $(src_dir)/,,$(2)) -o $(1)
> > >  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > >            echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
> > >            printf %s `dirname $(1)`/ > $(1) && \
> > 
> > That solves the issue and is probably better than passing more
> > compiler
> > arguments, thanks!
> 
> This will only work if we are compiling from the OpenSBI source
> directory
> itself. What if users compile OpenSBI with a different current
> directory
> using "make -C <opensbi_source_path>". I guess passing compiler
> argument will allow "make -C <opensbi_source_path>".

make -C <directory> will switch the path to <directory> first, so the
result is the same.

Regards,
Xiang W

> 
> Regards,
> Anup
> 
> > 
> > 
> > live well,
> >   vagrant
> > --
> > opensbi mailing list
> > opensbi@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi
Vagrant Cascadian Nov. 27, 2021, 1:48 a.m. UTC | #8 
On 2021-11-22, Xiang W. wrote:
> 在 2021-11-22星期一的 10:13 +0530，Anup Patel写道：
>> On Mon, Nov 22, 2021 at 10:02 AM Vagrant Cascadian
>> <vagrant@reproducible-builds.org> wrote:
>> > 
>> > On 2021-11-22, Xiang W. wrote:
>> > > 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
>> > > > of the directories below, I built using the same toolchain from
>> > > > the same git commit...
>> > > > 
>> > > > $ cd /home/vagrant/src/opensbi/opensbi1
>> > > > $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
>> > > > PLATFORM=generic
>> > > > ...
>> > > > $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
>> > > > /home/vagrant
>> > > > /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
>> > ...
>> > > This is because the source file uses the absolute path when
>> > > compiling,
>> > > you can use the relative path by modifying the Makefile
>> > > 
>> > > diff --git a/Makefile b/Makefile
>> > > index 8623c1c..d017534 100644
>> > > --- a/Makefile
>> > > +++ b/Makefile
>> > > @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p
>> > > `dirname
>> > > $(1)`; \
>> > >              -MM $(2) >> $(1) || rm -f $(1)
>> > >  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
>> > >            echo " CC        $(subst $(build_dir)/,,$(1))"; \
>> > > -          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
>> > > $(2) -
>> > > o $(1)
>> > > +          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
>> > > $(subst $(src_dir)/,,$(2)) -o $(1)
>> > >  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
>> > >            echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
>> > >            printf %s `dirname $(1)`/ > $(1) && \
>> > 
>> > That solves the issue and is probably better than passing more
>> > compiler
>> > arguments, thanks!
>> 
>> This will only work if we are compiling from the OpenSBI source
>> directory
>> itself. What if users compile OpenSBI with a different current
>> directory
>> using "make -C <opensbi_source_path>". I guess passing compiler
>> argument will allow "make -C <opensbi_source_path>".
>
> make -C <directory> will switch the path to <directory> first, so the
> result is the same.

Any outstanding concerns with proposing the patch by Xiang W to pass
relative directories instead of the original patch I submitted?

Should it be submitted by Xiang W or should I merge the commit message
from the original patch and submit it myself?

Thanks!


live well,
  vagrant
Anup Patel Nov. 27, 2021, 4:20 a.m. UTC | #9 
On 27/11/21, 8:24 AM, "opensbi on behalf of Vagrant Cascadian" <opensbi-bounces@lists.infradead.org on behalf of vagrant@reproducible-builds.org> wrote:

    On 2021-11-22, Xiang W. wrote:
    > 在 2021-11-22星期一的 10:13 +0530，Anup Patel写道：
    >> On Mon, Nov 22, 2021 at 10:02 AM Vagrant Cascadian
    >> <vagrant@reproducible-builds.org> wrote:
    >> > 
    >> > On 2021-11-22, Xiang W. wrote:
    >> > > 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
    >> > > > of the directories below, I built using the same toolchain from
    >> > > > the same git commit...
    >> > > > 
    >> > > > $ cd /home/vagrant/src/opensbi/opensbi1
    >> > > > $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
    >> > > > PLATFORM=generic
    >> > > > ...
    >> > > > $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
    >> > > > /home/vagrant
    >> > > > /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
    >> > ...
    >> > > This is because the source file uses the absolute path when
    >> > > compiling,
    >> > > you can use the relative path by modifying the Makefile
    >> > > 
    >> > > diff --git a/Makefile b/Makefile
    >> > > index 8623c1c..d017534 100644
    >> > > --- a/Makefile
    >> > > +++ b/Makefile
    >> > > @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p
    >> > > `dirname
    >> > > $(1)`; \
    >> > >              -MM $(2) >> $(1) || rm -f $(1)
    >> > >  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
    >> > >            echo " CC        $(subst $(build_dir)/,,$(1))"; \
    >> > > -          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
    >> > > $(2) -
    >> > > o $(1)
    >> > > +          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
    >> > > $(subst $(src_dir)/,,$(2)) -o $(1)
    >> > >  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
    >> > >            echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
    >> > >            printf %s `dirname $(1)`/ > $(1) && \
    >> > 
    >> > That solves the issue and is probably better than passing more
    >> > compiler
    >> > arguments, thanks!
    >> 
    >> This will only work if we are compiling from the OpenSBI source
    >> directory
    >> itself. What if users compile OpenSBI with a different current
    >> directory
    >> using "make -C <opensbi_source_path>". I guess passing compiler
    >> argument will allow "make -C <opensbi_source_path>".
    >
    > make -C <directory> will switch the path to <directory> first, so the
    > result is the same.

    Any outstanding concerns with proposing the patch by Xiang W to pass
    relative directories instead of the original patch I submitted?

    Should it be submitted by Xiang W or should I merge the commit message
    from the original patch and submit it myself?

[Anup] Change the patch subject to "Makefile: strip embedded file paths"
and send v2 patch.
[Anup] Please use "git send-email" to send patch to opensbi mailing list.
You will have to join the mailing list before posting because it allows
posting by mailing list members only.

Regards,
Anup

    Thanks!


    live well,
      vagrant
Xiang W Nov. 27, 2021, 11:46 a.m. UTC | #10 
在 2021-11-26星期五的 17:48 -0800，Vagrant Cascadian写道：
> On 2021-11-22, Xiang W. wrote:
> > 在 2021-11-22星期一的 10:13 +0530，Anup Patel写道：
> > > On Mon, Nov 22, 2021 at 10:02 AM Vagrant Cascadian
> > > <vagrant@reproducible-builds.org> wrote:
> > > > 
> > > > On 2021-11-22, Xiang W. wrote:
> > > > > 在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
> > > > > > of the directories below, I built using the same toolchain
> > > > > > from
> > > > > > the same git commit...
> > > > > > 
> > > > > > $ cd /home/vagrant/src/opensbi/opensbi1
> > > > > > $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> > > > > > PLATFORM=generic
> > > > > > ...
> > > > > > $ strings build/platform/generic/firmware/fw_dynamic.bin |
> > > > > > grep
> > > > > > /home/vagrant
> > > > > > /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
> > > > ...
> > > > > This is because the source file uses the absolute path when
> > > > > compiling,
> > > > > you can use the relative path by modifying the Makefile
> > > > > 
> > > > > diff --git a/Makefile b/Makefile
> > > > > index 8623c1c..d017534 100644
> > > > > --- a/Makefile
> > > > > +++ b/Makefile
> > > > > @@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p
> > > > > `dirname
> > > > > $(1)`; \
> > > > >              -MM $(2) >> $(1) || rm -f $(1)
> > > > >  compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > > > >            echo " CC        $(subst $(build_dir)/,,$(1))"; \
> > > > > -          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> > > > > $(2) -
> > > > > o $(1)
> > > > > +          $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
> > > > > $(subst $(src_dir)/,,$(2)) -o $(1)
> > > > >  compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > > > >            echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
> > > > >            printf %s `dirname $(1)`/ > $(1) && \
> > > > 
> > > > That solves the issue and is probably better than passing more
> > > > compiler
> > > > arguments, thanks!
> > > 
> > > This will only work if we are compiling from the OpenSBI source
> > > directory
> > > itself. What if users compile OpenSBI with a different current
> > > directory
> > > using "make -C <opensbi_source_path>". I guess passing compiler
> > > argument will allow "make -C <opensbi_source_path>".
> > 
> > make -C <directory> will switch the path to <directory> first, so
> > the
> > result is the same.
> 
> Any outstanding concerns with proposing the patch by Xiang W to pass
> relative directories instead of the original patch I submitted?
> 
> Should it be submitted by Xiang W or should I merge the commit
> message
> from the original patch and submit it myself?
I just made a suggestion, you can submit it.

Regards,
Xiang W
> 
> Thanks!
> 
> 
> live well,
>   vagrant
diff mbox series

Patch

From cf8aaf3ecc0b3b78a62a15839fa1d90263a2f5bb Mon Sep 17 00:00:00 2001
From: Vagrant Cascadian <vagrant@reproducible-builds.org>
Date: Thu, 18 Nov 2021 16:33:06 -0800
Subject: [PATCH] Pass -ffile-prefix-map to ensure reproducible builds
 regardless of build path.

Upstream commit 12753d22563f7d2d01f2c6644c7b66b06eb5c90f introduced
uses of __FILE__ which may result in the build path getting embedded
into the resulting binary.

https://reproducible-builds.org/docs/build-path/

Signed-off-by: Vagrant Cascadian <vagrant@reproducible-builds.org>
---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index 8623c1c..c597088 100644
--- a/Makefile
+++ b/Makefile
@@ -284,6 +284,7 @@  CFLAGS		+=	$(GENFLAGS)
 CFLAGS		+=	$(platform-cflags-y)
 CFLAGS		+=	-fno-pie -no-pie
 CFLAGS		+=	$(firmware-cflags-y)
+CFLAGS		+=	-ffile-prefix-map=$(CURDIR)=.
 
 CPPFLAGS	+=	$(GENFLAGS)
 CPPFLAGS	+=	$(platform-cppflags-y)
-- 
2.30.2