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From: Sergey Bugaev <bugaevc@gmail.com>
To: libc-alpha@sourceware.org, bug-hurd@gnu.org
Cc: Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>, Luca <luca@orpolo.org>
Subject: [PATCH v2 09/20] aarch64: Move saving user entry into _dl_start_user
Date: Sat, 23 Mar 2024 20:32:50 +0300	[thread overview]
Message-ID: <20240323173301.151066-10-bugaevc@gmail.com> (raw)
In-Reply-To: <20240323173301.151066-1-bugaevc@gmail.com>

In the Hurd ports, _dl_start () does not return the normal way; instead,
_dl_sysdep_start () jumps to _dl_start_user directly using the RETURN_TO
macro.  Unlike in the i386 and x86_64 ports, the instruction that was
saving the returned user entry into a different register (to avoid it
getting clobbered by the _dl_init () call) was not marked as a part of
_dl_start_user, causing it to be skipped when jumping to _dl_start_user
using RETURN_TO, and control subsequently getting transferred to a
random address left in x21.

This should not make any difference for Linux ports, other than the
_dl_start_user label pointing to an earlier instruction.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---
 sysdeps/aarch64/dl-start.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sysdeps/aarch64/dl-start.S b/sysdeps/aarch64/dl-start.S
index d645484e..e35431ca 100644
--- a/sysdeps/aarch64/dl-start.S
+++ b/sysdeps/aarch64/dl-start.S
@@ -29,10 +29,10 @@ ENTRY (_start)
 	PTR_ARG (0)
 	bl	_dl_start
 	/* Returns user entry point in x0.  */
-	mov	PTR_REG (21), PTR_REG (0)
 .globl _dl_start_user
 .type _dl_start_user, %function
 _dl_start_user:
+	mov	PTR_REG (21), PTR_REG (0)
 	/* Get argc.  */
 	ldr	PTR_REG (1), [sp]
 	/* Get argv.  */
-- 
2.44.0


  parent reply	other threads:[~2024-03-23 17:38 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-23 17:32 [PATCH v2 00/20] aarch64-gnu port & GNU/Hurd on AArch64 progress Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 01/20] hurd: Move internal functions to internal header Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 02/20] hurd: Stop relying on VM_MAX_ADDRESS Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 03/20] Allow glibc to be compiled without EXEC_PAGESIZE Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 04/20] hurd: Disable Prefer_MAP_32BIT_EXEC on non-x86_64 for now Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 05/20] hurd: Use the RETURN_ADDRESS macro Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 06/20] htl: Respect GL(dl_stack_flags) when allocating stacks Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 07/20] aarch64: Move pointer_guard.h out of sysdeps/unix/sysv/linux Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 08/20] aarch64: Add dl-procinfo Sergey Bugaev
2024-03-23 17:32 ` Sergey Bugaev [this message]
2024-03-23 17:32 ` [PATCH v2 10/20] aarch64: Allow building without kernel support for BTI Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 11/20] mach: Add a basic AArch64 port Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 12/20] mach: Declare the new thread_set_self_state () trap Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 13/20] hurd: Add a basic AArch64 port Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 14/20] hurd: Implement TLS on AArch64 Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 15/20] hurd: Implement longjmp for AArch64 Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 16/20] Add FPE_FLTIDO Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 17/20] hurd: Add an AArch64 signal implementation Sergey Bugaev
2024-03-23 17:32 ` [PATCH v2 18/20] htl: Implement some support for TLS_DTV_AT_TP Sergey Bugaev
2024-03-23 17:33 ` [PATCH v2 19/20] htl: Add an AArch64 implementation Sergey Bugaev
2024-03-23 17:33 ` [PATCH v2 20/20] hurd: Add expected aarch64-gnu abistlists Sergey Bugaev
2024-03-23 22:16 ` [PATCH v2 00/20] aarch64-gnu port & GNU/Hurd on AArch64 progress Samuel Thibault
2024-03-26  8:29 ` Sergey Bugaev
2024-03-26 10:15   ` Maxim Kuvyrkov

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