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* [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r
@ 2020-12-17 14:41 H.J. Lu
  2020-12-17 15:03 ` Andreas Schwab
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2020-12-17 14:41 UTC (permalink / raw)
  To: binutils

Set ELFOSABI_GNU for SHF_GNU_RETAIN sections only when generating
relocatable output since SHF_GNU_RETAIN has no impact on shared object
nor executable.

I will check it in tomorrow if there are no objections.


H.J.
---
bfd/

	PR ld/27091
	* elf.c (_bfd_elf_final_write_processing): Set ELFOSABI_GNU
	for SHF_GNU_RETAIN sections only when generating ET_REL output.

ld/

	PR ld/27091
	* testsuite/ld-elf/retain7.s: New file.
	* testsuite/ld-elf/retain7a.d: Likewise.
	* testsuite/ld-elf/retain7b.d: Likewise.
---
 bfd/elf.c                      |  8 +++++---
 ld/testsuite/ld-elf/retain7.s  |  5 +++++
 ld/testsuite/ld-elf/retain7a.d | 11 +++++++++++
 ld/testsuite/ld-elf/retain7b.d | 10 ++++++++++
 4 files changed, 31 insertions(+), 3 deletions(-)
 create mode 100644 ld/testsuite/ld-elf/retain7.s
 create mode 100644 ld/testsuite/ld-elf/retain7a.d
 create mode 100644 ld/testsuite/ld-elf/retain7b.d

diff --git a/bfd/elf.c b/bfd/elf.c
index 9c82912aeb..e601bfc1de 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -12466,9 +12466,11 @@ _bfd_elf_final_write_processing (bfd *abfd)
     i_ehdrp->e_ident[EI_OSABI] = get_elf_backend_data (abfd)->elf_osabi;
 
   /* Set the osabi field to ELFOSABI_GNU if the binary contains
-     SHF_GNU_MBIND or SHF_GNU_RETAIN sections or symbols of STT_GNU_IFUNC type
-     or STB_GNU_UNIQUE binding.  */
-  if (elf_tdata (abfd)->has_gnu_osabi != 0)
+     SHF_GNU_MBIND sections or symbols of STT_GNU_IFUNC type or
+     or STB_GNU_UNIQUE binding.  Set the osabi field to ELFOSABI_GNU
+     for SHF_GNU_RETAIN sections only when generating ET_REL output.  */
+  if ((elf_tdata (abfd)->has_gnu_osabi
+      & (i_ehdrp->e_type == ET_REL ? -1 : ~elf_gnu_osabi_retain)) != 0)
     {
       if (i_ehdrp->e_ident[EI_OSABI] == ELFOSABI_NONE)
 	i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_GNU;
diff --git a/ld/testsuite/ld-elf/retain7.s b/ld/testsuite/ld-elf/retain7.s
new file mode 100644
index 0000000000..a6cc86988c
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7.s
@@ -0,0 +1,5 @@
+	.type _start,"function"
+	.section .text,"axR",%progbits
+	.global _start
+_start:
+	.nop
diff --git a/ld/testsuite/ld-elf/retain7a.d b/ld/testsuite/ld-elf/retain7a.d
new file mode 100644
index 0000000000..544ff8a173
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7a.d
@@ -0,0 +1,11 @@
+#name: SHF_GNU_RETAIN 7a
+#source: retain7.s
+#ld: -e _start --gc-sections
+#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
+#readelf: -h
+
+#failif
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
diff --git a/ld/testsuite/ld-elf/retain7b.d b/ld/testsuite/ld-elf/retain7b.d
new file mode 100644
index 0000000000..0e5b12b335
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7b.d
@@ -0,0 +1,10 @@
+#name: SHF_GNU_RETAIN 7a
+#source: retain7.s
+#ld: -r
+#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
+#readelf: -h
+
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
-- 
2.29.2


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r
  2020-12-17 14:41 [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r H.J. Lu
@ 2020-12-17 15:03 ` Andreas Schwab
  2020-12-17 15:21   ` H.J. Lu
  0 siblings, 1 reply; 6+ messages in thread
From: Andreas Schwab @ 2020-12-17 15:03 UTC (permalink / raw)
  To: H.J. Lu via Binutils

On Dez 17 2020, H.J. Lu via Binutils wrote:

> Set ELFOSABI_GNU for SHF_GNU_RETAIN sections only when generating
> relocatable output since SHF_GNU_RETAIN has no impact on shared object
> nor executable.

Then it should not be set in the first place.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r
  2020-12-17 15:03 ` Andreas Schwab
@ 2020-12-17 15:21   ` H.J. Lu
  2020-12-17 15:25     ` Andreas Schwab
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2020-12-17 15:21 UTC (permalink / raw)
  To: Andreas Schwab; +Cc: H.J. Lu via Binutils

On Thu, Dec 17, 2020 at 7:04 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Dez 17 2020, H.J. Lu via Binutils wrote:
>
> > Set ELFOSABI_GNU for SHF_GNU_RETAIN sections only when generating
> > relocatable output since SHF_GNU_RETAIN has no impact on shared object
> > nor executable.
>
> Then it should not be set in the first place.
>

 ELFOSABI_GNU should be set on relocatable output since SHF_GNU_RETAIN
is in OS-specific range.

-- 
H.J.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r
  2020-12-17 15:21   ` H.J. Lu
@ 2020-12-17 15:25     ` Andreas Schwab
  2020-12-17 15:59       ` [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link H.J. Lu
  0 siblings, 1 reply; 6+ messages in thread
From: Andreas Schwab @ 2020-12-17 15:25 UTC (permalink / raw)
  To: H.J. Lu; +Cc: H.J. Lu via Binutils

On Dez 17 2020, H.J. Lu wrote:

> since SHF_GNU_RETAIN is in OS-specific range.

Exactly.  Without the marking, the object cannot be properly
interpreted.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link
  2020-12-17 15:25     ` Andreas Schwab
@ 2020-12-17 15:59       ` H.J. Lu
  2020-12-18 11:04         ` Alan Modra
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2020-12-17 15:59 UTC (permalink / raw)
  To: Andreas Schwab; +Cc: H.J. Lu via Binutils

[-- Attachment #1: Type: text/plain, Size: 269 bytes --]

On Thu, Dec 17, 2020 at 7:25 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Dez 17 2020, H.J. Lu wrote:
>
> > since SHF_GNU_RETAIN is in OS-specific range.
>
> Exactly.  Without the marking, the object cannot be properly
> interpreted.
>

Like this.

-- 
H.J.

[-- Attachment #2: 0001-elf-Copy-elf_gnu_osabi_retain-only-for-relocatable-l.patch --]
[-- Type: text/x-patch, Size: 2753 bytes --]

From b64e25f781c1b3ade8a119b350d5b8db114ab514 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 17 Dec 2020 06:34:14 -0800
Subject: [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link

Copy elf_gnu_osabi_retain from input only for relocatable link since
SHF_GNU_RETAIN has no impact on non-relocatable outputs.

bfd/

	PR ld/27091
	* elflink.c (elf_link_input_bfd): Copy elf_gnu_osabi_retain
	from input only for relocatable link.

ld/

	PR ld/27091
	* testsuite/ld-elf/retain7.s: New file.
	* testsuite/ld-elf/retain7a.d: Likewise.
	* testsuite/ld-elf/retain7b.d: Likewise.
---
 bfd/elflink.c                  |  4 +++-
 ld/testsuite/ld-elf/retain7.s  |  5 +++++
 ld/testsuite/ld-elf/retain7a.d | 11 +++++++++++
 ld/testsuite/ld-elf/retain7b.d | 10 ++++++++++
 4 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 ld/testsuite/ld-elf/retain7.s
 create mode 100644 ld/testsuite/ld-elf/retain7a.d
 create mode 100644 ld/testsuite/ld-elf/retain7b.d

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 2489700da7..1b3398126f 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -10806,7 +10806,9 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
       || bed->elf_osabi == ELFOSABI_GNU
       || bed->elf_osabi == ELFOSABI_FREEBSD)
     elf_tdata (output_bfd)->has_gnu_osabi
-      |= elf_tdata (input_bfd)->has_gnu_osabi;
+      |= (elf_tdata (input_bfd)->has_gnu_osabi
+	  & (bfd_link_relocatable (flinfo->info)
+	     ? -1 : ~elf_gnu_osabi_retain));
 
   /* Read the local symbols.  */
   isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
diff --git a/ld/testsuite/ld-elf/retain7.s b/ld/testsuite/ld-elf/retain7.s
new file mode 100644
index 0000000000..a6cc86988c
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7.s
@@ -0,0 +1,5 @@
+	.type _start,"function"
+	.section .text,"axR",%progbits
+	.global _start
+_start:
+	.nop
diff --git a/ld/testsuite/ld-elf/retain7a.d b/ld/testsuite/ld-elf/retain7a.d
new file mode 100644
index 0000000000..544ff8a173
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7a.d
@@ -0,0 +1,11 @@
+#name: SHF_GNU_RETAIN 7a
+#source: retain7.s
+#ld: -e _start --gc-sections
+#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
+#readelf: -h
+
+#failif
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
diff --git a/ld/testsuite/ld-elf/retain7b.d b/ld/testsuite/ld-elf/retain7b.d
new file mode 100644
index 0000000000..0e5b12b335
--- /dev/null
+++ b/ld/testsuite/ld-elf/retain7b.d
@@ -0,0 +1,10 @@
+#name: SHF_GNU_RETAIN 7a
+#source: retain7.s
+#ld: -r
+#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
+#readelf: -h
+
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
-- 
2.29.2


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link
  2020-12-17 15:59       ` [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link H.J. Lu
@ 2020-12-18 11:04         ` Alan Modra
  0 siblings, 0 replies; 6+ messages in thread
From: Alan Modra @ 2020-12-18 11:04 UTC (permalink / raw)
  To: H.J. Lu; +Cc: Andreas Schwab, H.J. Lu via Binutils

On Thu, Dec 17, 2020 at 07:59:45AM -0800, H.J. Lu via Binutils wrote:
> On Thu, Dec 17, 2020 at 7:25 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
> >
> > On Dez 17 2020, H.J. Lu wrote:
> >
> > > since SHF_GNU_RETAIN is in OS-specific range.
> >
> > Exactly.  Without the marking, the object cannot be properly
> > interpreted.
> >
> 
> Like this.

Looks good.

> 
> -- 
> H.J.

> From b64e25f781c1b3ade8a119b350d5b8db114ab514 Mon Sep 17 00:00:00 2001
> From: "H.J. Lu" <hjl.tools@gmail.com>
> Date: Thu, 17 Dec 2020 06:34:14 -0800
> Subject: [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link
> 
> Copy elf_gnu_osabi_retain from input only for relocatable link since
> SHF_GNU_RETAIN has no impact on non-relocatable outputs.
> 
> bfd/
> 
> 	PR ld/27091
> 	* elflink.c (elf_link_input_bfd): Copy elf_gnu_osabi_retain
> 	from input only for relocatable link.
> 
> ld/
> 
> 	PR ld/27091
> 	* testsuite/ld-elf/retain7.s: New file.
> 	* testsuite/ld-elf/retain7a.d: Likewise.
> 	* testsuite/ld-elf/retain7b.d: Likewise.
> ---
>  bfd/elflink.c                  |  4 +++-
>  ld/testsuite/ld-elf/retain7.s  |  5 +++++
>  ld/testsuite/ld-elf/retain7a.d | 11 +++++++++++
>  ld/testsuite/ld-elf/retain7b.d | 10 ++++++++++
>  4 files changed, 29 insertions(+), 1 deletion(-)
>  create mode 100644 ld/testsuite/ld-elf/retain7.s
>  create mode 100644 ld/testsuite/ld-elf/retain7a.d
>  create mode 100644 ld/testsuite/ld-elf/retain7b.d
> 
> diff --git a/bfd/elflink.c b/bfd/elflink.c
> index 2489700da7..1b3398126f 100644
> --- a/bfd/elflink.c
> +++ b/bfd/elflink.c
> @@ -10806,7 +10806,9 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
>        || bed->elf_osabi == ELFOSABI_GNU
>        || bed->elf_osabi == ELFOSABI_FREEBSD)
>      elf_tdata (output_bfd)->has_gnu_osabi
> -      |= elf_tdata (input_bfd)->has_gnu_osabi;
> +      |= (elf_tdata (input_bfd)->has_gnu_osabi
> +	  & (bfd_link_relocatable (flinfo->info)
> +	     ? -1 : ~elf_gnu_osabi_retain));
>  
>    /* Read the local symbols.  */
>    isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
> diff --git a/ld/testsuite/ld-elf/retain7.s b/ld/testsuite/ld-elf/retain7.s
> new file mode 100644
> index 0000000000..a6cc86988c
> --- /dev/null
> +++ b/ld/testsuite/ld-elf/retain7.s
> @@ -0,0 +1,5 @@
> +	.type _start,"function"
> +	.section .text,"axR",%progbits
> +	.global _start
> +_start:
> +	.nop
> diff --git a/ld/testsuite/ld-elf/retain7a.d b/ld/testsuite/ld-elf/retain7a.d
> new file mode 100644
> index 0000000000..544ff8a173
> --- /dev/null
> +++ b/ld/testsuite/ld-elf/retain7a.d
> @@ -0,0 +1,11 @@
> +#name: SHF_GNU_RETAIN 7a
> +#source: retain7.s
> +#ld: -e _start --gc-sections
> +#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
> +#readelf: -h
> +
> +#failif
> +ELF Header:
> +#...
> +  OS/ABI:                            UNIX - GNU
> +#pass
> diff --git a/ld/testsuite/ld-elf/retain7b.d b/ld/testsuite/ld-elf/retain7b.d
> new file mode 100644
> index 0000000000..0e5b12b335
> --- /dev/null
> +++ b/ld/testsuite/ld-elf/retain7b.d
> @@ -0,0 +1,10 @@
> +#name: SHF_GNU_RETAIN 7a
> +#source: retain7.s
> +#ld: -r
> +#notarget: ![supports_gnu_osabi] ![check_gc_sections_available]
> +#readelf: -h
> +
> +ELF Header:
> +#...
> +  OS/ABI:                            UNIX - GNU
> +#pass
> -- 
> 2.29.2
> 


-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-12-18 11:04 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-17 14:41 [PATCH] elf: Set ELFOSABI_GNU for SHF_GNU_RETAIN only for ld -r H.J. Lu
2020-12-17 15:03 ` Andreas Schwab
2020-12-17 15:21   ` H.J. Lu
2020-12-17 15:25     ` Andreas Schwab
2020-12-17 15:59       ` [PATCH] elf: Copy elf_gnu_osabi_retain only for relocatable link H.J. Lu
2020-12-18 11:04         ` Alan Modra

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