From: "H.J. Lu" <hjl.tools@gmail.com>
To: Fangrui Song <i@maskray.me>
Cc: binutils@sourceware.org
Subject: [PATCH] x86: Check static link of dynamic objects
Date: Fri, 13 Mar 2020 05:29:47 -0700 [thread overview]
Message-ID: <20200313122947.GA404470@gmail.com> (raw)
In-Reply-To: <20200312040920.GA43870@gmail.com>
On Wed, Mar 11, 2020 at 09:09:20PM -0700, Fangrui Song wrote:
> > When -static is passed to gcc, gcc passes it to linker before any input
> > files to create static executable. If -Bdynamic is also passed to linker
> > from command-line, linker should issue an error if dynamic object is used.
> >
> > include/
> >
> > PR ld/24920
> > * bfdlink.h (bfd_link_info): Add static_exec.
> >
> > ld/
> >
> > PR ld/24920
> > * ldfile.c (ldfile_try_open_bfd): Also check link_info.static_exec
> > for static link of dynamic object.
> > * lexsup.c (parse_args): Set link_info.static_exec to true if we
> > see -static before any input files.
> > * testsuite/ld-elf/pr24920.err: New file.
> > * testsuite/ld-elf/shared.exp: Run ld/24920 tests.
>
> Does the patch reject valid use case like:
>
> ld -Bstatic a.o -Bdynamic b.so
>
This isn't a valid use case for Linux/x86. At minimum, -dynamic-linker
is needed for Linux/x86 to create non-static executable unless
--no-dynamic-linker is used.
> If the gcc driver detects the input file type, I think such an error should be emitted on its side.?
>
The GCC driver passes everything at command-line to linker without any
checking.
>
> -static = -Bstatic. There is no need to teach it to know that the first -static/-Bstatic is different.
I am testing this patch. I will check it in there are no issues.
H.J.
---
On Linux/x86, when -static is passed to gcc, gcc passes it to linker
before all input files suitable for creating static executable. X86
linker will report error for dynamic input objects if -static is passed
at command-line before all input files without --dynamic-linker unless
--no-dynamic-linker is used.
bfd/
PR ld/24920
* elf-linker-x86.h (elf_linker_x86_params): Add
static_before_all_inputs and has_dynamic_linker.
* elfxx-x86.c (_bfd_x86_elf_link_setup_gnu_properties): Report
dynamic input objects if -static is passed at command-line
before all input files without --dynamic-linker unless
--no-dynamic-linker is used.
ld/
PR ld/24920
* emulparams/elf32_x86_64.sh: Use static.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/static.sh: New file.
* emultempl/elf-x86.em: Include "ldlex.h".
* testsuite/ld-elf/pr24920.err: New file.
* testsuite/ld-elf/linux-x86.exp: Run ld/24920 tests.
---
bfd/elf-linker-x86.h | 6 ++++++
bfd/elfxx-x86.c | 17 ++++++++++++++++
ld/emulparams/elf32_x86_64.sh | 1 +
ld/emulparams/elf_i386.sh | 1 +
ld/emulparams/elf_x86_64.sh | 1 +
ld/emulparams/static.sh | 12 +++++++++++
ld/emultempl/elf-x86.em | 1 +
ld/testsuite/ld-elf/linux-x86.exp | 33 +++++++++++++++++++++++++++----
ld/testsuite/ld-elf/pr24920.err | 1 +
9 files changed, 69 insertions(+), 4 deletions(-)
create mode 100644 ld/emulparams/static.sh
create mode 100644 ld/testsuite/ld-elf/pr24920.err
diff --git a/bfd/elf-linker-x86.h b/bfd/elf-linker-x86.h
index 8ede7299dd..d0cb20dde5 100644
--- a/bfd/elf-linker-x86.h
+++ b/bfd/elf-linker-x86.h
@@ -49,6 +49,12 @@ struct elf_linker_x86_params
/* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
unsigned int call_nop_as_suffix : 1;
+ /* TRUE if -static is passed at command-line before all input files. */
+ unsigned int static_before_all_inputs : 1;
+
+ /* TRUE if --dynamic-linker is passed at command-line. */
+ unsigned int has_dynamic_linker : 1;
+
/* Report missing IBT and SHSTK properties. */
enum elf_x86_cet_report cet_report;
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 2e0e01e31d..108e04a158 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -2998,6 +2998,23 @@ _bfd_x86_elf_link_setup_gnu_properties
: bed->plt_alignment);
}
+ if (bfd_link_executable (info)
+ && !info->nointerp
+ && !htab->params->has_dynamic_linker
+ && htab->params->static_before_all_inputs)
+ {
+ /* Report error for dynamic input objects if -static is passed at
+ command-line before all input files without --dynamic-linker
+ unless --no-dynamic-linker is used. */
+ bfd *abfd;
+
+ for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
+ if ((abfd->flags & DYNAMIC))
+ info->callbacks->einfo
+ (_("%X%P: attempted static link of dynamic object `%pB'\n"),
+ abfd);
+ }
+
return pbfd;
}
diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh
index 249553aaac..1f672c6e42 100644
--- a/ld/emulparams/elf32_x86_64.sh
+++ b/ld/emulparams/elf32_x86_64.sh
@@ -4,6 +4,7 @@ source_sh ${srcdir}/emulparams/dynamic_undefined_weak.sh
source_sh ${srcdir}/emulparams/reloc_overflow.sh
source_sh ${srcdir}/emulparams/call_nop.sh
source_sh ${srcdir}/emulparams/cet.sh
+source_sh ${srcdir}/emulparams/static.sh
SCRIPT_NAME=elf
ELFSIZE=32
OUTPUT_FORMAT="elf32-x86-64"
diff --git a/ld/emulparams/elf_i386.sh b/ld/emulparams/elf_i386.sh
index 645707ddbd..c98d5e6600 100644
--- a/ld/emulparams/elf_i386.sh
+++ b/ld/emulparams/elf_i386.sh
@@ -3,6 +3,7 @@ source_sh ${srcdir}/emulparams/extern_protected_data.sh
source_sh ${srcdir}/emulparams/dynamic_undefined_weak.sh
source_sh ${srcdir}/emulparams/call_nop.sh
source_sh ${srcdir}/emulparams/cet.sh
+source_sh ${srcdir}/emulparams/static.sh
SCRIPT_NAME=elf
OUTPUT_FORMAT="elf32-i386"
NO_RELA_RELOCS=yes
diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh
index 2b34941986..be98082982 100644
--- a/ld/emulparams/elf_x86_64.sh
+++ b/ld/emulparams/elf_x86_64.sh
@@ -4,6 +4,7 @@ source_sh ${srcdir}/emulparams/dynamic_undefined_weak.sh
source_sh ${srcdir}/emulparams/reloc_overflow.sh
source_sh ${srcdir}/emulparams/call_nop.sh
source_sh ${srcdir}/emulparams/cet.sh
+source_sh ${srcdir}/emulparams/static.sh
SCRIPT_NAME=elf
ELFSIZE=64
OUTPUT_FORMAT="elf64-x86-64"
diff --git a/ld/emulparams/static.sh b/ld/emulparams/static.sh
new file mode 100644
index 0000000000..410839b8a5
--- /dev/null
+++ b/ld/emulparams/static.sh
@@ -0,0 +1,12 @@
+PARSE_AND_LIST_ARGS_CASES="$PARSE_AND_LIST_ARGS_CASES
+ case OPTION_DYNAMIC_LINKER:
+ params.has_dynamic_linker = TRUE;
+ return FALSE;
+
+ case OPTION_NON_SHARED:
+ /* Check if -static is passed at command-line before all input
+ files. */
+ if (!lang_has_input_file)
+ params.static_before_all_inputs = TRUE;
+ return FALSE;
+"
diff --git a/ld/emultempl/elf-x86.em b/ld/emultempl/elf-x86.em
index 8de4491699..e18caffbb2 100644
--- a/ld/emultempl/elf-x86.em
+++ b/ld/emultempl/elf-x86.em
@@ -22,6 +22,7 @@
#
fragment <<EOF
+#include "ldlex.h"
#include "elf-linker-x86.h"
static struct elf_linker_x86_params params;
diff --git a/ld/testsuite/ld-elf/linux-x86.exp b/ld/testsuite/ld-elf/linux-x86.exp
index d304fb1442..63a321b966 100644
--- a/ld/testsuite/ld-elf/linux-x86.exp
+++ b/ld/testsuite/ld-elf/linux-x86.exp
@@ -19,11 +19,36 @@
# MA 02110-1301, USA.
#
+# Linux/x86 tests.
+if { ![istarget "i?86-*-linux*"] \
+ && ![istarget "x86_64-*-linux*"] \
+ && ![istarget "amd64-*-linux*"] } {
+ return
+}
+
+run_ld_link_tests [list \
+ [list \
+ "Build pr24920.so" \
+ "-shared" \
+ "" \
+ "" \
+ {dummy.s} \
+ {} \
+ "pr24920.so" \
+ ] \
+ [list \
+ "Build pr24920" \
+ "-static " \
+ "-Bdynamic tmpdir/pr24920.so" \
+ "" \
+ {start.s} \
+ {{ld pr24920.err}} \
+ "pr24920" \
+ ] \
+]
+
# Test very simple native Linux/x86 programs with linux-x86.S.
-if { ![isnative] || ![check_compiler_available] \
- || (![istarget "i?86-*-linux*"] \
- && ![istarget "x86_64-*-linux*"] \
- && ![istarget "amd64-*-linux*"]) } {
+if { ![isnative] || ![check_compiler_available] } {
return
}
diff --git a/ld/testsuite/ld-elf/pr24920.err b/ld/testsuite/ld-elf/pr24920.err
new file mode 100644
index 0000000000..8f5cab9167
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr24920.err
@@ -0,0 +1 @@
+.*: attempted static link of dynamic object `tmpdir/pr24920.so'
--
2.24.1
next prev parent reply other threads:[~2020-03-13 12:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 23:57 [PATCH] ld: Properly check static link of dynamic object H.J. Lu
2020-03-12 4:09 ` Fangrui Song
2020-03-13 12:29 ` H.J. Lu [this message]
2020-03-13 23:12 ` [PATCH] x86: Check static link of dynamic objects Alan Modra
2020-03-12 4:19 ` [PATCH] ld: Properly check static link of dynamic object Alan Modra
2020-03-12 9:36 ` H.J. Lu
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