From: Samuel Thibault <samuel.thibault@gnu.org>
To: Sergey Bugaev <bugaevc@gmail.com>
Cc: libc-alpha@sourceware.org, bug-hurd@gnu.org
Subject: Re: [RFC PATCH 07/23] hurd: Pass the data pointer to _hurd_stack_setup explicitly
Date: Thu, 4 Jan 2024 23:47:12 +0100 [thread overview]
Message-ID: <20240104224712.ytpwgdbcpmknivhh@begin> (raw)
In-Reply-To: <20240103171502.1358371-8-bugaevc@gmail.com>
Applied, thanks!
Sergey Bugaev, le mer. 03 janv. 2024 20:14:40 +0300, a ecrit:
> Instead of relying on the stack frame layout to figure out where the stack
> pointer was prior to the _hurd_stack_setup () call, just pass the pointer
> as an argument explicitly. This is less brittle and much more portable.
>
> Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> ---
> sysdeps/mach/hurd/i386/static-start.S | 3 +++
> sysdeps/mach/hurd/x86/init-first.c | 16 +++++++---------
> sysdeps/mach/hurd/x86_64/static-start.S | 1 +
> 3 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/sysdeps/mach/hurd/i386/static-start.S b/sysdeps/mach/hurd/i386/static-start.S
> index d83505b2..3ffcb47d 100644
> --- a/sysdeps/mach/hurd/i386/static-start.S
> +++ b/sysdeps/mach/hurd/i386/static-start.S
> @@ -19,7 +19,10 @@
> .text
> .globl _start
> _start:
> + pushl %esp
> call _hurd_stack_setup
> + /* No need to "addl %4, %esp", since _hurd_stack_setup
> + * returns with an already adjusted stack pointer. */
> xorl %edx, %edx
> jmp _start1
>
> diff --git a/sysdeps/mach/hurd/x86/init-first.c b/sysdeps/mach/hurd/x86/init-first.c
> index bb051418..6f71d71b 100644
> --- a/sysdeps/mach/hurd/x86/init-first.c
> +++ b/sysdeps/mach/hurd/x86/init-first.c
> @@ -197,7 +197,7 @@ strong_alias (posixland_init, __libc_init_first);
> which should not exist at all. */
> void
> inhibit_stack_protector
> -_hurd_stack_setup (void)
> +_hurd_stack_setup (void **argptr)
> {
> /* This is the very first C code that runs in a statically linked
> executable -- calling this function is the first thing that _start in
> @@ -206,14 +206,12 @@ _hurd_stack_setup (void)
>
> _start1 expects the arguments, environment, and a Hurd data block to be
> located at the top of the stack. The data may already be located there,
> - or we may need to receive it from the exec server. */
> - void *caller = __builtin_extract_return_addr (__builtin_return_address (0));
> - /* If the arguments and environment are already located on the stack, this is
> - where they are, just above our call frame. Note that this may not be a
> - valid pointer in case we're supposed to receive the arguments from the exec
> - server, so we can not dereference it yet. */
> - void **p = (void **) __builtin_frame_address (0) + 2;
> + or we may need to receive it from the exec server. If the data is located
> + on the stack (just above our call frame), argptr points to it. Note that
> + this may not be a valid pointer in case we're supposed to receive the
> + arguments from the exec server, so we can not dereference it yet. */
>
> + void *caller = __builtin_extract_return_addr (__builtin_return_address (0));
> /* Init the essential things. */
> first_init ();
>
> @@ -245,7 +243,7 @@ _hurd_stack_setup (void)
> the stack pointer to the data (which is somewhere on the current stack
> anyway). This way, _start1 find the data on the top of the stack, just as
> it expects to. */
> - _hurd_startup (p, &doinit);
> + _hurd_startup (argptr, &doinit);
> __builtin_unreachable ();
> }
> #endif
> diff --git a/sysdeps/mach/hurd/x86_64/static-start.S b/sysdeps/mach/hurd/x86_64/static-start.S
> index 9b9db937..0ec00905 100644
> --- a/sysdeps/mach/hurd/x86_64/static-start.S
> +++ b/sysdeps/mach/hurd/x86_64/static-start.S
> @@ -25,6 +25,7 @@ _start:
> leaq __strlen_sse2(%rip), %rax
> movq %rax, strlen@GOTPCREL(%rip)
>
> + movq %rsp, %rdi
> call _hurd_stack_setup
> xorq %rdx, %rdx
> jmp _start1
> --
> 2.43.0
>
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.
next prev parent reply other threads:[~2024-01-04 22:47 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-03 17:14 [RFC PATCH 00/23] aarch64-gnu port Sergey Bugaev
2024-01-03 17:14 ` [PATCH 01/23] hurd: Add some missing includes Sergey Bugaev
2024-01-03 20:43 ` Samuel Thibault
2024-01-03 21:08 ` Sergey Bugaev
2024-01-03 21:24 ` Sergey Bugaev
2024-01-03 21:35 ` Samuel Thibault
2024-01-03 21:00 ` Samuel Thibault
2024-01-03 17:14 ` [PATCH 02/23] hurd: Declare _hurd_intr_rpc_msg* with protected visibility Sergey Bugaev
2024-01-03 21:00 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 03/23] Allow glibc to be compiled without EXEC_PAGESIZE Sergey Bugaev
2024-03-11 16:13 ` Florian Weimer
2024-03-25 11:58 ` Florian Weimer
2024-03-25 12:24 ` Sergey Bugaev
2024-04-10 11:57 ` Florian Weimer
2024-04-15 12:53 ` Sergey Bugaev
2024-04-22 21:01 ` Samuel Thibault
2024-01-03 17:14 ` [PATCH 04/23] mach: Drop some unnecessary vm_param.h includes Sergey Bugaev
2024-01-03 21:00 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 05/23] hurd: Disable Prefer_MAP_32BIT_EXEC on non-x86_64 for now Sergey Bugaev
2024-01-03 17:14 ` [PATCH 06/23] mach: Drop SNARF_ARGS macro Sergey Bugaev
2024-01-03 21:00 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 07/23] hurd: Pass the data pointer to _hurd_stack_setup explicitly Sergey Bugaev
2024-01-04 22:47 ` Samuel Thibault [this message]
2024-01-03 17:14 ` [RFC PATCH 08/23] hurd: Drop x86-specific assembly from init-first.c Sergey Bugaev
2024-01-04 22:48 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 09/23] hurd: Make init-first.c no longer x86-specific Sergey Bugaev
2024-01-04 22:48 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 10/23] hurd: Only init early static TLS if it's used to store stack or pointer guards Sergey Bugaev
2024-01-04 22:48 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 11/23] hurd: Initializy _dl_pagesize early in static builds Sergey Bugaev
2024-01-04 22:48 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 12/23] aarch64: Make cpu-features definitions not Linux-specific Sergey Bugaev
2024-01-04 22:48 ` Samuel Thibault
2024-01-03 17:14 ` [RFC PATCH 13/23] aarch64: Add dl-procinfo Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 14/23] aarch64: Allow building without kernel support for BTI Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 15/23] mach: Add a basic AArch64 port Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 16/23] hurd: " Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 17/23] hurd: Implement TLS on AArch64 Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 18/23] hurd: Implement longjmp for AArch64 Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 19/23] Add FPE_FLTIDO Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 20/23] hurd: Add an AArch64 signal implementation Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 21/23] htl: Implement some support for TLS_DTV_AT_TP Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 22/23] htl: Add an AArch64 implementation Sergey Bugaev
2024-01-03 17:14 ` [RFC PATCH 23/23] hurd: Add expected aarch64-gnu abistlists Sergey Bugaev
2024-01-03 17:30 ` [RFC PATCH 00/23] aarch64-gnu port Joseph Myers
2024-01-03 17:57 ` Sergey Bugaev
2024-03-11 16:10 ` Florian Weimer
2024-03-11 13:47 ` H.J. Lu
2024-03-11 15:38 ` Sergey Bugaev
2024-03-11 14:14 ` Maxim Kuvyrkov
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