From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Evgeniy Baskov <baskov@ispras.ru>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Alexey Khoroshilov <khoroshilov@ispras.ru>,
Peter Jones <pjones@redhat.com>,
Gerd Hoffmann <kraxel@redhat.com>, Dave Young <dyoung@redhat.com>,
Mario Limonciello <mario.limonciello@amd.com>,
Kees Cook <keescook@chromium.org>,
Tom Lendacky <thomas.lendacky@amd.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Joerg Roedel <jroedel@suse.de>
Subject: [PATCH v4 18/21] x86/head_64: Store boot_params pointer in callee-preserved register
Date: Fri, 2 Jun 2023 12:13:10 +0200 [thread overview]
Message-ID: <20230602101313.3557775-19-ardb@kernel.org> (raw)
In-Reply-To: <20230602101313.3557775-1-ardb@kernel.org>
Instead of pushing/popping %RSI to/from the stack every time a function
is called from startup_64(), store it in a callee preserved register
and grab it from there when its value is actualled needed.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/kernel/head_64.S | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index a5df3e994f04f10f..95b12fdae10e1dc9 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -60,6 +60,7 @@ SYM_CODE_START_NOALIGN(startup_64)
* compiled to run at we first fixup the physical addresses in our page
* tables and then reload them.
*/
+ mov %rsi, %r15 /* Preserve boot_params pointer */
/* Set up the stack for verify_cpu() */
leaq (__end_init_task - PTREGS_SIZE)(%rip), %rsp
@@ -73,9 +74,7 @@ SYM_CODE_START_NOALIGN(startup_64)
shrq $32, %rdx
wrmsr
- pushq %rsi
call startup_64_setup_env
- popq %rsi
#ifdef CONFIG_AMD_MEM_ENCRYPT
/*
@@ -84,10 +83,8 @@ SYM_CODE_START_NOALIGN(startup_64)
* which needs to be done before any CPUID instructions are executed in
* subsequent code.
*/
- movq %rsi, %rdi
- pushq %rsi
+ movq %r15, %rdi
call sme_enable
- popq %rsi
#endif
/* Now switch to __KERNEL_CS so IRET works reliably */
@@ -109,9 +106,7 @@ SYM_CODE_START_NOALIGN(startup_64)
* programmed into CR3.
*/
leaq _text(%rip), %rdi
- pushq %rsi
call __startup_64
- popq %rsi
/* Form the CR3 value being sure to include the CR3 modifier */
addq $(early_top_pgt - __START_KERNEL_map), %rax
@@ -200,10 +195,8 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
* %rsi carries pointer to realmode data and is callee-clobbered. Save
* and restore it.
*/
- pushq %rsi
movq %rax, %rdi
call sev_verify_cbit
- popq %rsi
/*
* Switch to new page-table
@@ -294,9 +287,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
wrmsr
/* Setup and Load IDT */
- pushq %rsi
call early_setup_idt
- popq %rsi
/* Check if nx is implemented */
movl $0x80000001, %eax
@@ -334,7 +325,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
/* rsi is pointer to real mode structure with interesting info.
pass it to C */
- movq %rsi, %rdi
+ movq %r15, %rdi
.Ljump_to_C_code:
/*
--
2.39.2
next prev parent reply other threads:[~2023-06-02 10:25 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-02 10:12 [PATCH v4 00/21] efi/x86: Avoid bare metal decompressor during EFI boot Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 01/21] x86/efistub: Branch straight to kernel entry point from C code Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 02/21] x86/efistub: Simplify and clean up handover entry code Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 03/21] x86/decompressor: Avoid magic offsets for EFI handover entrypoint Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 04/21] x86/efistub: Clear BSS in EFI handover protocol entrypoint Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 05/21] x86/decompressor: Use proper sequence to take the address of the GOT Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 06/21] x86/decompressor: Store boot_params pointer in callee save register Ard Biesheuvel
2023-06-02 10:12 ` [PATCH v4 07/21] x86/decompressor: Call trampoline as a normal function Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 08/21] x86/decompressor: Use standard calling convention for trampoline Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 09/21] x86/decompressor: Avoid the need for a stack in the 32-bit trampoline Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 10/21] x86/decompressor: Call trampoline directly from C code Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 11/21] x86/decompressor: Only call the trampoline when changing paging levels Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 12/21] x86/decompressor: Merge trampoline cleanup with switching code Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 13/21] x86/efistub: Perform 4/5 level paging switch from the stub Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 14/21] x86/efistub: Prefer EFI memory attributes protocol over DXE services Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 15/21] decompress: Use 8 byte alignment Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 16/21] x86/decompressor: Move global symbol references to C code Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 17/21] x86/decompressor: Factor out kernel decompression and relocation Ard Biesheuvel
2023-06-02 10:13 ` Ard Biesheuvel [this message]
2023-06-02 10:13 ` [PATCH v4 19/21] efi/libstub: Add limit argument to efi_random_alloc() Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 20/21] x86/efistub: Perform SNP feature test while running in the firmware Ard Biesheuvel
2023-06-02 20:38 ` Tom Lendacky
2023-06-02 20:39 ` Tom Lendacky
2023-06-02 21:29 ` Ard Biesheuvel
2023-06-02 22:01 ` Tom Lendacky
2023-06-02 22:22 ` Ard Biesheuvel
2023-06-02 10:13 ` [PATCH v4 21/21] x86/efistub: Avoid legacy decompressor when doing EFI boot Ard Biesheuvel
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