[PATCH] powerpc/64: place .text immediately following .head.text

[PATCH] powerpc/64: place .text immediately following .head.text

[Nicholas Piggin]

Do not introduce any additional alignment. Placement of text section
will be set by fixed section macros. Without this, output section
alignment defaults to 4096, which makes BookE text section start at
0x1000 when it is expected to start at 0x100.

This was introduced by 57f266497d81 ("powerpc: Use gas sections for
arranging exception vectors") and was caught with the scripted head
section checker (not yet merged).

Fixes: 57f266497d81
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/vmlinux.lds.S | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 8295f51..7394b77 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -94,8 +94,17 @@ SECTIONS
 	 * detected, and will result in a crash at boot due to offsets being
 	 * wrong.
 	 */
+#ifdef CONFIG_PPC64
+	/*
+	 * BLOCK(0) overrides the default output section alignment because
+	 * this needs to start right after .head.text in order for fixed
+	 * section placement to work.
+	 */
+	.text BLOCK(0) : AT(ADDR(.text) - LOAD_OFFSET) {
+#else
 	.text : AT(ADDR(.text) - LOAD_OFFSET) {
 		ALIGN_FUNCTION();
+#endif
 		/* careful! __ftr_alt_* sections need to be close to .text */
 		*(.text .fixup __ftr_alt_* .ref.text)
 		SCHED_TEXT
-- 
2.10.2

Re: powerpc/64: place .text immediately following .head.text

[Michael Ellerman]

On Sat, 2016-11-26 at 03:20:31 UTC, Nicholas Piggin wrote:
> Do not introduce any additional alignment. Placement of text section
> will be set by fixed section macros. Without this, output section
> alignment defaults to 4096, which makes BookE text section start at
> 0x1000 when it is expected to start at 0x100.
> 
> This was introduced by 57f266497d81 ("powerpc: Use gas sections for
> arranging exception vectors") and was caught with the scripted head
> section checker (not yet merged).
> 
> Fixes: 57f266497d81
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/dadc4a1bb9f0095343ed9dd4f1d9f3

cheers