Hi Marcus,

applied, tested and pushed.

best regards Waldemar

Marcus Hähnel wrote,

Hello devs,

The _start symbol does not necessarily have to be on the first page of the application. But the __ehdr_start symbol is always at address zero for PIE binaries.

So now we know how it works ;)

Best regards,

• Marcus

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From 6bff37e29b34740e2ff0d2b6b8ab57e54c0580ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jan=20Kl=C3=B6tzke?= jan.kloetzke@kernkonzept.com Date: Wed, 19 Mar 2025 08:04:44 +0100 Subject: [PATCH] Use __ehdr_start as known zero link address symbol

The _start symbol does not necessarily have to be on the first page of the application. But the __ehdr_start symbol is always at address zero for PIE binaries.

Signed-off-by: Marcus Haehnel marcus.haehnel@kernkonzept.com

libc/sysdeps/linux/aarch64/crt1.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libc/sysdeps/linux/aarch64/crt1.S b/libc/sysdeps/linux/aarch64/crt1.S index e9f946894..965d3265d 100644 --- a/libc/sysdeps/linux/aarch64/crt1.S +++ b/libc/sysdeps/linux/aarch64/crt1.S @@ -52,8 +52,8 @@ _start: /* Save off the atexit pointer */ mov x19, x0

• /* Calculate load address... idk how this works, but it does */
• adrp x0, _start

• /* "Calculate" load address. The link address of __ehdr_start is 0. */

• adrp x0, __ehdr_start

  /* Do relocations */ bl reloc_static_pie

-- 2.47.1

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