From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Andy Lutomirski <luto@amacapital.net>,
Balbir Singh <bsingharora@gmail.com>,
Borislav Petkov <bp@alien8.de>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eugene Syromiatnikov <esyr@redhat.com>,
Florian Weimer <fweimer@redhat.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v8 13/14] x86: Discard .note.gnu.property sections
Date: Tue, 13 Aug 2019 13:53:58 -0700 [thread overview]
Message-ID: <20190813205359.12196-14-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20190813205359.12196-1-yu-cheng.yu@intel.com>
From: "H.J. Lu" <hjl.tools@gmail.com>
With the command-line option, -mx86-used-note=yes, the x86 assembler
in binutils 2.32 and above generates a program property note in a note
section, .note.gnu.property, to encode used x86 ISAs and features.
To exclude .note.gnu.property sections from NOTE segment in x86 kernel
linker script:
PHDRS {
text PT_LOAD FLAGS(5);
data PT_LOAD FLAGS(6);
percpu PT_LOAD FLAGS(6);
init PT_LOAD FLAGS(7);
note PT_NOTE FLAGS(0);
}
SECTIONS
{
...
.notes : AT(ADDR(.notes) - 0xffffffff80000000) { __start_notes = .; KEEP(*(.not
e.*)) __stop_notes = .; } :text :note
...
}
this patch discards .note.gnu.property sections in kernel linker script
by adding
/DISCARD/ : {
*(.note.gnu.property)
}
before .notes sections. Since .exit.text and .exit.data sections are
discarded at runtime, it undefines EXIT_TEXT and EXIT_DATA to exclude
.exit.text and .exit.data sections from default discarded sections.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
arch/x86/kernel/vmlinux.lds.S | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e2feacf921a0..5ef137493a85 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -146,6 +146,10 @@ SECTIONS
_etext = .;
} :text = 0x9090
+ /* .note.gnu.property sections should be discarded */
+ /DISCARD/ : {
+ *(.note.gnu.property)
+ }
NOTES :text :note
EXCEPTION_TABLE(16) :text = 0x9090
@@ -415,6 +419,12 @@ SECTIONS
STABS_DEBUG
DWARF_DEBUG
+ /* Sections to be discarded. EXIT_TEXT and EXIT_DATA discard at
+ * runtime, not link time. */
+#undef EXIT_TEXT
+#define EXIT_TEXT
+#undef EXIT_DATA
+#define EXIT_DATA
DISCARDS
/DISCARD/ : {
*(.eh_frame)
--
2.17.1
next prev parent reply other threads:[~2019-08-13 20:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 20:53 [PATCH v8 00/14] Control-flow Enforcement: Branch Tracking, PTRACE Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 01/14] x86/cet/ibt: Add Kconfig option for user-mode Indirect Branch Tracking Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 02/14] x86/cet/ibt: User-mode indirect branch tracking support Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 03/14] x86/cet/ibt: Handle signals for end branch Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 04/14] mm/mmap: Add IBT bitmap size to address space limit check Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 05/14] x86/cet/ibt: ELF header parsing for IBT Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 06/14] x86/cet/ibt: Add arch_prctl functions " Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 07/14] x86/cet/ibt: Add ENDBR to op-code-map Yu-cheng Yu
2019-11-08 13:19 ` Adrian Hunter
2019-08-13 20:53 ` [PATCH v8 08/14] x86/vdso: Insert endbr32/endbr64 to vDSO Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 09/14] x86/vdso/32: Add ENDBR32 to __kernel_vsyscall entry point Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 10/14] x86/vsyscall/64: Add ENDBR64 to vsyscall entry points Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 11/14] x86/vsyscall/64: Fixup shadow stack and branch tracking for vsyscall Yu-cheng Yu
2019-08-13 20:53 ` [PATCH v8 12/14] x86/cet: Add PTRACE interface for CET Yu-cheng Yu
2019-08-13 20:53 ` Yu-cheng Yu [this message]
2019-08-13 20:53 ` [PATCH v8 14/14] Introduce arch_prctl(ARCH_X86_CET_MARK_LEGACY_CODE) Yu-cheng Yu
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