[PATCH v5 0/1] Makefile: rework u-boot-initial-env target

[PATCH v5 0/1] Makefile: rework u-boot-initial-env target

[Max Krummenacher]

From: Max Krummenacher <max.krummenacher@toradex.com>


With CONFIG_LTO enabled the current way of extracting the
configured environment no longer works, i.e. the object file
content changes due to LTO.

Build a host tool which prints the configured environment instead
of using objcopy and friends to achive the same.

The code and Makefile changes were mostly stolen from tools/env/
i.e. the target userspace tools to access the environment.


Changes in v5:
- don't build the printinitialenv tool unconditionally but build it
  only as part of the u-boot-initial-env target.
  This no longer fails the 'make tools-only_defconfig tools-only'
  use-case which is reported by Tom Rini.
  Adding the $(env_h) dependencies to the tools target might give
  circular dependencies issues with some future tool.
- add Acked-by: Pali Rohár <pali@kernel.org>

Changes in v4:
- add '(objtree)/' when calling the tool. Suggested by Pali Rohár.
- renamed patch, as more than just the Makefile has changes

Changes in v3:
- moved the tool from scripts/ to tools/. Suggested by Tom Rini
- changed the dependencies to '$(env_h)' and 'tools'.
  Suggested by Tom Rini and Pali Rohár.
- removed the sed rule which replaces \x00 with \x0A as this is already
  done by the tool. Suggested by Pali Rohár.

Changes in v2:
- reworked to build a host tool which prints the configured
  environment as proposed by Pali Rohár
  https://lore.kernel.org/u-boot/20221018174827.1393211-1-max.oss.09@gmail.com/
- renamed patch, v1 used "Makefile: fix u-boot-initial-env target if lto is enabled"

Max Krummenacher (1):
  u-boot-initial-env: rework make target

 Makefile                | 10 ++++++----
 tools/.gitignore        |  1 +
 tools/Makefile          |  4 ++++
 tools/printinitialenv.c | 44 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 tools/printinitialenv.c

-- 
2.35.3

[PATCH v5 1/1] u-boot-initial-env: rework make target

[Max Krummenacher]

From: Max Krummenacher <max.krummenacher@toradex.com>

With LTO enabled the U-Boot initial environment is no longer stored
in an easy accessible section in env/common.o. I.e. the section name
changes from build to build, its content maybe compressed and it is
annotated with additional data.

Drop trying to read the initial env with elf tools from the compiler
specific object file in favour of adding and using a host tool with
the only functionality of printing the initial env to stdout.

See also:
https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Acked-by: Pali Rohár <pali@kernel.org>

---

Changes in v5:
- don't build the printinitialenv tool unconditionally but build it
  only as part of the u-boot-initial-env target.
  This no longer fails the 'make tools-only_defconfig tools-only'
  use-case which is reported by Tom Rini.
  Adding the $(env_h) dependencies to the tools target might give
  circular dependencies issues with some future tool.
- add Acked-by: Pali Rohár <pali@kernel.org>

Changes in v4:
- add '(objtree)/' when calling the tool. Suggested by Pali Rohár.
- renamed patch, as more than just the Makefile has changes

Changes in v3:
- moved the tool from scripts/ to tools/. Suggested by Tom Rini
- changed the dependencies to '$(env_h)' and 'tools'.
  Suggested by Tom Rini and Pali Rohár.
- removed the sed rule which replaces \x00 with \x0A as this is already
  done by the tool. Suggested by Pali Rohár.

Changes in v2:
- reworked to build a host tool which prints the configured
  environment as proposed by Pali Rohár
  https://lore.kernel.org/u-boot/20221018174827.1393211-1-max.oss.09@gmail.com/
- renamed patch, v1 used "Makefile: fix u-boot-initial-env target if lto is enabled"

 Makefile                | 10 ++++++----
 tools/.gitignore        |  1 +
 tools/Makefile          |  4 ++++
 tools/printinitialenv.c | 44 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 tools/printinitialenv.c

diff --git a/Makefile b/Makefile
index 2d24ac3959f..32e4bef10f5 100644
--- a/Makefile
+++ b/Makefile
@@ -2439,11 +2439,13 @@ endif
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 quiet_cmd_genenv = GENENV  $@
-cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
-	sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
-	sort --field-separator== -k1,1 --stable $@ -o $@
+cmd_genenv = \
+	$(objtree)/tools/printinitialenv | \
+	sed -e '/^\s*$$/d' | \
+	sort --field-separator== -k1,1 --stable -o $@
 
-u-boot-initial-env: u-boot.bin
+u-boot-initial-env: $(env_h) FORCE
+	$(Q)$(MAKE) $(build)=tools $(objtree)/tools/printinitialenv
 	$(call if_changed,genenv)
 
 # Consistency checks
diff --git a/tools/.gitignore b/tools/.gitignore
index d3a93ff294a..28e8ce2a07a 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -28,6 +28,7 @@
 /mxsboot
 /ncb
 /prelink-riscv
+/printinitialenv
 /proftool
 /relocate-rela
 /spl_size_limit
diff --git a/tools/Makefile b/tools/Makefile
index 26be0a7ba2e..80bc62befcb 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -275,6 +275,10 @@ clean-dirs := lib common
 
 always := $(hostprogs-y)
 
+# Host tool to dump the currently configured default environment,
+# build it on demand, i.e. not add it to 'always'.
+hostprogs-y += printinitialenv
+
 # Generated LCD/video logo
 LOGO_H = $(objtree)/include/bmp_logo.h
 LOGO_DATA_H = $(objtree)/include/bmp_logo_data.h
diff --git a/tools/printinitialenv.c b/tools/printinitialenv.c
new file mode 100644
index 00000000000..c58b234d679
--- /dev/null
+++ b/tools/printinitialenv.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2022
+ * Max Krummenacher, Toradex
+ *
+ * Snippets taken from tools/env/fw_env.c
+ *
+ * This prints the list of default environment variables as currently
+ * configured.
+ *
+ */
+
+#include <stdio.h>
+
+/* Pull in the current config to define the default environment */
+#include <linux/kconfig.h>
+
+#ifndef __ASSEMBLY__
+#define __ASSEMBLY__ /* get only #defines from config.h */
+#include <config.h>
+#undef	__ASSEMBLY__
+#else
+#include <config.h>
+#endif
+
+#define DEFAULT_ENV_INSTANCE_STATIC
+#include <generated/environment.h>
+#include <env_default.h>
+
+int main(void)
+{
+	char *env, *nxt;
+
+	for (env = default_environment; *env; env = nxt + 1) {
+		for (nxt = env; *nxt; ++nxt) {
+			if (nxt >= &default_environment[sizeof(default_environment)]) {
+				fprintf(stderr, "## Error: environment not terminated\n");
+				return -1;
+			}
+		}
+		printf("%s\n", env);
+	}
+	return 0;
+}
-- 
2.35.3

Re: [PATCH v5 1/1] u-boot-initial-env: rework make target

[Simon Glass]

Hi Max,

On Mon, 28 Nov 2022 at 21:41, Max Krummenacher <max.oss.09@gmail.com> wrote:
>
> From: Max Krummenacher <max.krummenacher@toradex.com>
>
> With LTO enabled the U-Boot initial environment is no longer stored
> in an easy accessible section in env/common.o. I.e. the section name
> changes from build to build, its content maybe compressed and it is
> annotated with additional data.
>
> Drop trying to read the initial env with elf tools from the compiler
> specific object file in favour of adding and using a host tool with
> the only functionality of printing the initial env to stdout.
>
> See also:
> https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/
>
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> Acked-by: Pali Rohár <pali@kernel.org>
>
> ---
>
> Changes in v5:
> - don't build the printinitialenv tool unconditionally but build it
>   only as part of the u-boot-initial-env target.
>   This no longer fails the 'make tools-only_defconfig tools-only'
>   use-case which is reported by Tom Rini.
>   Adding the $(env_h) dependencies to the tools target might give
>   circular dependencies issues with some future tool.
> - add Acked-by: Pali Rohár <pali@kernel.org>
>
> Changes in v4:
> - add '(objtree)/' when calling the tool. Suggested by Pali Rohár.
> - renamed patch, as more than just the Makefile has changes
>
> Changes in v3:
> - moved the tool from scripts/ to tools/. Suggested by Tom Rini
> - changed the dependencies to '$(env_h)' and 'tools'.
>   Suggested by Tom Rini and Pali Rohár.
> - removed the sed rule which replaces \x00 with \x0A as this is already
>   done by the tool. Suggested by Pali Rohár.
>
> Changes in v2:
> - reworked to build a host tool which prints the configured
>   environment as proposed by Pali Rohár
>   https://lore.kernel.org/u-boot/20221018174827.1393211-1-max.oss.09@gmail.com/
> - renamed patch, v1 used "Makefile: fix u-boot-initial-env target if lto is enabled"
>
>  Makefile                | 10 ++++++----
>  tools/.gitignore        |  1 +
>  tools/Makefile          |  4 ++++
>  tools/printinitialenv.c | 44 +++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 55 insertions(+), 4 deletions(-)
>  create mode 100644 tools/printinitialenv.c

Reviewed-by: Simon Glass <sjg@chromium.org>

It would be nice to have a test for this. It could go in test_env.py
and you can use test_event.py as an example.


- Simon


>
> diff --git a/Makefile b/Makefile
> index 2d24ac3959f..32e4bef10f5 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -2439,11 +2439,13 @@ endif
>         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
>
>  quiet_cmd_genenv = GENENV  $@
> -cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
> -       sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
> -       sort --field-separator== -k1,1 --stable $@ -o $@
> +cmd_genenv = \
> +       $(objtree)/tools/printinitialenv | \
> +       sed -e '/^\s*$$/d' | \
> +       sort --field-separator== -k1,1 --stable -o $@
>
> -u-boot-initial-env: u-boot.bin
> +u-boot-initial-env: $(env_h) FORCE
> +       $(Q)$(MAKE) $(build)=tools $(objtree)/tools/printinitialenv
>         $(call if_changed,genenv)
>
>  # Consistency checks
> diff --git a/tools/.gitignore b/tools/.gitignore
> index d3a93ff294a..28e8ce2a07a 100644
> --- a/tools/.gitignore
> +++ b/tools/.gitignore
> @@ -28,6 +28,7 @@
>  /mxsboot
>  /ncb
>  /prelink-riscv
> +/printinitialenv
>  /proftool
>  /relocate-rela
>  /spl_size_limit
> diff --git a/tools/Makefile b/tools/Makefile
> index 26be0a7ba2e..80bc62befcb 100644
> --- a/tools/Makefile
> +++ b/tools/Makefile
> @@ -275,6 +275,10 @@ clean-dirs := lib common
>
>  always := $(hostprogs-y)
>
> +# Host tool to dump the currently configured default environment,
> +# build it on demand, i.e. not add it to 'always'.
> +hostprogs-y += printinitialenv
> +
>  # Generated LCD/video logo
>  LOGO_H = $(objtree)/include/bmp_logo.h
>  LOGO_DATA_H = $(objtree)/include/bmp_logo_data.h
> diff --git a/tools/printinitialenv.c b/tools/printinitialenv.c
> new file mode 100644
> index 00000000000..c58b234d679
> --- /dev/null
> +++ b/tools/printinitialenv.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * (C) Copyright 2022
> + * Max Krummenacher, Toradex
> + *
> + * Snippets taken from tools/env/fw_env.c
> + *
> + * This prints the list of default environment variables as currently
> + * configured.
> + *
> + */
> +
> +#include <stdio.h>
> +
> +/* Pull in the current config to define the default environment */
> +#include <linux/kconfig.h>
> +
> +#ifndef __ASSEMBLY__
> +#define __ASSEMBLY__ /* get only #defines from config.h */
> +#include <config.h>
> +#undef __ASSEMBLY__
> +#else
> +#include <config.h>
> +#endif
> +
> +#define DEFAULT_ENV_INSTANCE_STATIC
> +#include <generated/environment.h>
> +#include <env_default.h>
> +
> +int main(void)
> +{
> +       char *env, *nxt;
> +
> +       for (env = default_environment; *env; env = nxt + 1) {
> +               for (nxt = env; *nxt; ++nxt) {
> +                       if (nxt >= &default_environment[sizeof(default_environment)]) {
> +                               fprintf(stderr, "## Error: environment not terminated\n");
> +                               return -1;
> +                       }
> +               }
> +               printf("%s\n", env);
> +       }
> +       return 0;
> +}
> --
> 2.35.3
>

Re: [PATCH v5 1/1] u-boot-initial-env: rework make target

[Tom Rini]

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On Mon, Nov 28, 2022 at 09:41:22AM +0100, Max Krummenacher wrote:

> From: Max Krummenacher <max.krummenacher@toradex.com>
> 
> With LTO enabled the U-Boot initial environment is no longer stored
> in an easy accessible section in env/common.o. I.e. the section name
> changes from build to build, its content maybe compressed and it is
> annotated with additional data.
> 
> Drop trying to read the initial env with elf tools from the compiler
> specific object file in favour of adding and using a host tool with
> the only functionality of printing the initial env to stdout.
> 
> See also:
> https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/
> 
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> Acked-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Simon Glass <sjg@chromium.org>

Applied to u-boot/next, thanks!

-- 
Tom

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Re: [PATCH v5 1/1] u-boot-initial-env: rework make target

[Max Krummenacher]

Hi Tom

On Thu, Dec 8, 2022 at 9:24 PM Tom Rini <trini@konsulko.com> wrote:
>
> On Mon, Nov 28, 2022 at 09:41:22AM +0100, Max Krummenacher wrote:
>
> > From: Max Krummenacher <max.krummenacher@toradex.com>
> >
> > With LTO enabled the U-Boot initial environment is no longer stored
> > in an easy accessible section in env/common.o. I.e. the section name
> > changes from build to build, its content maybe compressed and it is
> > annotated with additional data.
> >
> > Drop trying to read the initial env with elf tools from the compiler
> > specific object file in favour of adding and using a host tool with
> > the only functionality of printing the initial env to stdout.
> >
> > See also:
> > https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/
> >
> > Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> > Acked-by: Pali Rohár <pali@kernel.org>
> > Reviewed-by: Simon Glass <sjg@chromium.org>
>
> Applied to u-boot/next, thanks!

The commit not only fixes the use case on arm64 with LTO enabled, it also
fixes sandbox for x86-64. For me on Fedora with a `gcc (GCC) 11.3.1 20220421`
both `make sandbox_defconfig; make u-boot-initial-env` and
`make sandbox_defconfig; <unselect LTO>; make u-boot-initial-env` fail with
```
  GENENV  u-boot-initial-env
objcopy: env/common.o: can't dump section
'.rodata.default_environment' - it does not exist: file format not
recognized
sed: can't read u-boot-initial-env: No such file or directory
```

Wouldn't that merit applying the commit to master, i.e. include it in v2023.01?

Regards
Max

P.S.:
The test in [1] catches this failure, so [1] should go in after this commit
to have CI tests not failing.
[1] https://lore.kernel.org/all/20221209120956.2286619-1-max.oss.09@gmail.com/

>
> --
> Tom

Re: [PATCH v5 1/1] u-boot-initial-env: rework make target

[Tom Rini]

[-- Attachment #1: Type: text/plain, Size: 1954 bytes --]

On Mon, Dec 12, 2022 at 02:39:09PM +0100, Max Krummenacher wrote:
> Hi Tom
> 
> On Thu, Dec 8, 2022 at 9:24 PM Tom Rini <trini@konsulko.com> wrote:
> >
> > On Mon, Nov 28, 2022 at 09:41:22AM +0100, Max Krummenacher wrote:
> >
> > > From: Max Krummenacher <max.krummenacher@toradex.com>
> > >
> > > With LTO enabled the U-Boot initial environment is no longer stored
> > > in an easy accessible section in env/common.o. I.e. the section name
> > > changes from build to build, its content maybe compressed and it is
> > > annotated with additional data.
> > >
> > > Drop trying to read the initial env with elf tools from the compiler
> > > specific object file in favour of adding and using a host tool with
> > > the only functionality of printing the initial env to stdout.
> > >
> > > See also:
> > > https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com/
> > >
> > > Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> > > Acked-by: Pali Rohár <pali@kernel.org>
> > > Reviewed-by: Simon Glass <sjg@chromium.org>
> >
> > Applied to u-boot/next, thanks!
> 
> The commit not only fixes the use case on arm64 with LTO enabled, it also
> fixes sandbox for x86-64. For me on Fedora with a `gcc (GCC) 11.3.1 20220421`
> both `make sandbox_defconfig; make u-boot-initial-env` and
> `make sandbox_defconfig; <unselect LTO>; make u-boot-initial-env` fail with
> ```
>   GENENV  u-boot-initial-env
> objcopy: env/common.o: can't dump section
> '.rodata.default_environment' - it does not exist: file format not
> recognized
> sed: can't read u-boot-initial-env: No such file or directory
> ```
> 
> Wouldn't that merit applying the commit to master, i.e. include it in v2023.01?

You can just disable LTO, and it's been an issue for a while now. It's
also easy enough to cherry-pick if there's cases out there that can't
wait.  Thanks again for addressing the problem!

-- 
Tom

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