From: Fangrui Song <maskray@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, Bill Wendling <morbo@google.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Ard Biesheuvel <ardb@kernel.org>,
Fangrui Song <maskray@google.com>
Subject: [PATCH] arm64: lds: move .got section out of .text
Date: Fri, 28 Apr 2023 05:04:42 +0000 [thread overview]
Message-ID: <20230428050442.180913-1-maskray@google.com> (raw)
Currently, the .got section is placed within the output section .text.
However, when .got is non-empty, the SHF_WRITE flag is set when linked
by lld. GNU ld recognizes .text as a special section and ignores the
SHF_WRITE flag. By renaming .text, we can also get the SHF_WRITE flag.
Conventionally, the .got section is placed just before .got.plt (which
should be empty and omitted in the kernel). Therefore, we move the .got
section to a conventional location (between .text and .data) and remove
the unneeded `. = ALIGN(16)`.
Signed-off-by: Fangrui Song <maskray@google.com>
---
arch/arm64/kernel/vmlinux.lds.S | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index b9202c2ee18e..2bcb3b30db41 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -181,18 +181,8 @@ SECTIONS
KPROBES_TEXT
HYPERVISOR_TEXT
*(.gnu.warning)
- . = ALIGN(16);
- *(.got) /* Global offset table */
}
- /*
- * Make sure that the .got.plt is either completely empty or it
- * contains only the lazy dispatch entries.
- */
- .got.plt : { *(.got.plt) }
- ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18,
- "Unexpected GOT/PLT entries detected!")
-
. = ALIGN(SEGMENT_ALIGN);
_etext = .; /* End of text section */
@@ -247,6 +237,16 @@ SECTIONS
. = ALIGN(SEGMENT_ALIGN);
__inittext_end = .;
+
+ .got : { *(.got) }
+ /*
+ * Make sure that the .got.plt is either completely empty or it
+ * contains only the lazy dispatch entries.
+ */
+ .got.plt : { *(.got.plt) }
+ ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18,
+ "Unexpected GOT/PLT entries detected!")
+
__initdata_begin = .;
init_idmap_pg_dir = .;
--
2.40.1.495.gc816e09b53d-goog
next reply other threads:[~2023-04-28 5:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-28 5:04 Fangrui Song [this message]
2023-04-28 7:29 ` Ard Biesheuvel
2023-04-28 18:58 ` Fangrui Song
2023-04-28 19:11 ` Ard Biesheuvel
2023-04-28 21:06 ` Fangrui Song
2023-04-28 21:25 ` Ard Biesheuvel
2023-04-28 22:29 ` Fangrui Song
2023-04-29 6:13 ` Ard Biesheuvel
2023-04-29 7:51 ` Fangrui Song
2023-04-29 8:14 ` Ard Biesheuvel
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