From: "H.J. Lu" <hjl.tools@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH] x86: Discard .note.gnu.property sections
Date: Mon, 24 Sep 2018 13:14:59 -0700 [thread overview]
Message-ID: <20180924201459.35923-1-hjl.tools@gmail.com> (raw)
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>
---
arch/x86/kernel/vmlinux.lds.S | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 8bde0a419f86..7e1e0ef1578a 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -138,6 +138,10 @@ SECTIONS
_etext = .;
} :text = 0x9090
+ /* .note.gnu.property sections should be discarded */
+ /DISCARD/ : {
+ *(.note.gnu.property)
+ }
NOTES :text :note
EXCEPTION_TABLE(16) :text = 0x9090
@@ -373,7 +377,12 @@ SECTIONS
STABS_DEBUG
DWARF_DEBUG
- /* Sections to be discarded */
+ /* 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
reply other threads:[~2018-09-24 20:15 UTC|newest]
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