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x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]

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GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
levels:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250

and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
GNU_PROPERTY_X86_ISA_1_V[234] marker:

https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13

Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by

commit b0ab06937385e0ae25cebf1991787d64f439bf12
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Oct 30 06:49:57 2020 -0700

    x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker

and

commit 32930e4edbc06bc6f10c435dbcc63131715df678
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Oct 9 05:05:57 2020 -0700

    x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker

GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
micro-architecture ISA level required to execute the binary.  The marker
must be added by programmers explicitly in one of 3 ways:

1. Pass -mneeded to GCC.
2. Add the marker in the linker inputs as this patch does.
3. Pass -z x86-64-v[234] to the linker.

Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker support to ld.so if binutils 2.32 or newer is used to build glibc:

1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
markers to elf.h.
2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker to abi-note.o based on the ISA level used to compile abi-note.o,
assuming that the same ISA level is used to compile the whole glibc.
3. Add isa_1 to cpu_features to record the supported x86 ISA level.
4. Rename _dl_process_cet_property_note to _dl_process_property_note and
add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
5. Update _rtld_main_check and _dl_open_check to check loaded objects
with the incompatible ISA level.
6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
on lesser platforms.
7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.

Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
x86-64-v4 machines.

Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
and got:

[hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
./elf/tst-isa-level-1: CPU ISA level is lower than required
[hjl@gnu-cfl-2 build-x86_64-linux]$
This commit is contained in:
H.J. Lu
2020-10-09 06:06:56 -07:00
parent 9e97f239ea
commit ecce11aa07
21 changed files with 642 additions and 111 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
sysdeps/x86/dl-cet.c
View File

@ -76,10 +76,12 @@ dl_cet_check (struct link_map *m, const char *program)
*/
enable_ibt &= (HAS_CPU_FEATURE (IBT)
&& (enable_ibt_type == cet_always_on
|| (m->l_cet & lc_ibt) != 0));
|| (m->l_x86_feature_1_and
& GNU_PROPERTY_X86_FEATURE_1_IBT) != 0));
enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
&& (enable_shstk_type == cet_always_on
|| (m->l_cet & lc_shstk) != 0));
|| (m->l_x86_feature_1_and
& GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0));
}
/* ld.so is CET-enabled by kernel. But shared objects may not
@ -111,7 +113,8 @@ dl_cet_check (struct link_map *m, const char *program)
/* IBT is enabled only if it is enabled in executable as
well as all shared objects. */
enable_ibt &= (enable_ibt_type == cet_always_on
|| (l->l_cet & lc_ibt) != 0);
|| (l->l_x86_feature_1_and
& GNU_PROPERTY_X86_FEATURE_1_IBT) != 0);
if (!found_ibt_legacy && enable_ibt != ibt_enabled)
{
found_ibt_legacy = true;
@ -121,7 +124,8 @@ dl_cet_check (struct link_map *m, const char *program)
/* SHSTK is enabled only if it is enabled in executable as
well as all shared objects. */
enable_shstk &= (enable_shstk_type == cet_always_on
|| (l->l_cet & lc_shstk) != 0);
|| (l->l_x86_feature_1_and
& GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0);
if (enable_shstk != shstk_enabled)
{
found_shstk_legacy = true;