From: Borislav Petkov <bp@alien8.de>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Michael Roth <michael.roth@amd.com>
Subject: Re: [PATCH v2 02/16] x86/compressed: efi-mixed: move 32-bit entrypoint code into .text section
Date: Thu, 6 Oct 2022 12:42:13 +0200 [thread overview]
Message-ID: <Yz6xBROUBPyaUSoB@zn.tnic> (raw)
In-Reply-To: <20220921145422.437618-3-ardb@kernel.org>
On Wed, Sep 21, 2022 at 04:54:08PM +0200, Ard Biesheuvel wrote:
> Move the code that stores the arguments passed to the EFI entrypoint
> into the .text section, so that it can be moved into a separate
> compilation unit in a subsequent patch.
>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
> arch/x86/boot/compressed/head_64.S | 34 ++++++++++++--------
> 1 file changed, 20 insertions(+), 14 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index d33f060900d2..1ba2fc2357e6 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -303,24 +303,28 @@ SYM_FUNC_START(efi32_stub_entry)
> popl %ecx
> popl %edx
> popl %esi
> + jmp efi32_entry
> +SYM_FUNC_END(efi32_stub_entry)
>
> + .text
> +SYM_FUNC_START_LOCAL(efi32_entry)
> call 1f
> -1: pop %ebp
> - subl $ rva(1b), %ebp
> -
> - movl %esi, rva(efi32_boot_args+8)(%ebp)
> -SYM_INNER_LABEL(efi32_pe_stub_entry, SYM_L_LOCAL)
> - movl %ecx, rva(efi32_boot_args)(%ebp)
> - movl %edx, rva(efi32_boot_args+4)(%ebp)
> - movb $0, rva(efi_is64)(%ebp)
> +1: pop %ebx
I'm guessing according to the EFI mixed mode calling convention, %ebx is
not a live register which gets overwritten here...?
Looking at efi32_pe_entry() from where this is called, %ebx looks live.
What am I missing?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-10-06 10:42 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-21 14:54 [PATCH v2 00/16] x86: head_64.S spring cleaning Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 01/16] x86/compressed: efi-mixed: rename efi_thunk_64.S to efi-mixed.S Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 02/16] x86/compressed: efi-mixed: move 32-bit entrypoint code into .text section Ard Biesheuvel
2022-10-06 10:42 ` Borislav Petkov [this message]
2022-10-06 10:56 ` Ard Biesheuvel
2022-10-06 11:13 ` Borislav Petkov
2022-10-06 11:19 ` Ard Biesheuvel
2022-10-06 12:27 ` Ard Biesheuvel
2022-10-07 8:56 ` Borislav Petkov
2022-09-21 14:54 ` [PATCH v2 03/16] x86/compressed: efi-mixed: move bootargs parsing out of 32-bit startup code Ard Biesheuvel
2022-10-06 11:03 ` Borislav Petkov
2022-10-06 11:29 ` Ard Biesheuvel
2022-10-07 9:30 ` Borislav Petkov
2022-09-21 14:54 ` [PATCH v2 04/16] x86/compressed: efi-mixed: move efi32_pe_entry into .text section Ard Biesheuvel
2022-11-17 15:57 ` Borislav Petkov
2022-11-17 16:06 ` Ard Biesheuvel
2022-11-17 17:08 ` Borislav Petkov
2022-09-21 14:54 ` [PATCH v2 05/16] x86/compressed: efi-mixed: move efi32_entry out of head_64.S Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 06/16] x86/compressed: efi-mixed: move efi32_pe_entry() " Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 07/16] x86/compressed: efi: merge multiple definitions of image_offset into one Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 08/16] x86/compressed: efi-mixed: simplify IDT/GDT preserve/restore Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 09/16] x86/compressed: avoid touching ECX in startup32_set_idt_entry() Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 10/16] x86/compressed: pull global variable ref up into startup32_load_idt() Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 11/16] x86/compressed: move startup32_load_idt() into .text section Ard Biesheuvel
2022-11-18 16:44 ` Borislav Petkov
2022-09-21 14:54 ` [PATCH v2 12/16] x86/compressed: move startup32_load_idt() out of head_64.S Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 13/16] x86/compressed: move startup32_check_sev_cbit() into .text Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 14/16] x86/compressed: move startup32_check_sev_cbit() out of head_64.S Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 15/16] x86/compressed: adhere to calling convention in get_sev_encryption_bit() Ard Biesheuvel
2022-09-21 14:54 ` [PATCH v2 16/16] x86/compressed: only build mem_encrypt.S if AMD_MEM_ENCRYPT=y Ard Biesheuvel
2022-11-18 18:26 ` [PATCH v2 00/16] x86: head_64.S spring cleaning Borislav Petkov
2022-11-18 23:31 ` Ard Biesheuvel
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