From: Ard Biesheuvel <ardb+git@google.com>
To: linux-kernel@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>,
Kevin Loughlin <kevinloughlin@google.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Dionna Glaze <dionnaglaze@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Justin Stitt <justinstitt@google.com>,
Brian Gerst <brgerst@gmail.com>,
linux-arch@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH v2 15/17] x86/sev: Use PIC codegen for early SEV startup code
Date: Thu, 25 Jan 2024 12:28:34 +0100 [thread overview]
Message-ID: <20240125112818.2016733-34-ardb+git@google.com> (raw)
In-Reply-To: <20240125112818.2016733-19-ardb+git@google.com>
From: Ard Biesheuvel <ardb@kernel.org>
Use PIC codegen for the compilation units containing code that may be
called very early during the boot, at which point the CPU still runs
from the 1:1 mapping of memory. This is necessary to prevent the
compiler from emitting absolute symbol references to addresses that are
not mapped yet.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/vmlinux.lds.S | 1 +
arch/x86/lib/Makefile | 2 +-
arch/x86/mm/Makefile | 3 ++-
4 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 65194ca79b5c..65677b25d803 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -24,6 +24,7 @@ endif
# head64.c contains C code that may execute from a different virtual address
# than it was linked at, so we always build it using PIE codegen
CFLAGS_head64.o += $(PIE_CFLAGS)
+CFLAGS_sev.o += $(PIE_CFLAGS)
KASAN_SANITIZE_head$(BITS).o := n
KASAN_SANITIZE_dumpstack.o := n
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 77262e804250..bbdccb6362a9 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -182,6 +182,7 @@ SECTIONS
DATA_DATA
CONSTRUCTORS
+ *(.data.rel .data.rel.*)
/* rarely changed data like cpu maps */
READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES)
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index ea3a28e7b613..87c79bb8d386 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -24,7 +24,7 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_cmdline.o = -pg
endif
-CFLAGS_cmdline.o := -fno-stack-protector -fno-jump-tables
+CFLAGS_cmdline.o := $(PIE_CFLAGS)
endif
inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index c80febc44cd2..b412009ae588 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -31,7 +31,8 @@ obj-y += pat/
# Make sure __phys_addr has no stackprotector
CFLAGS_physaddr.o := -fno-stack-protector
-CFLAGS_mem_encrypt_identity.o := -fno-stack-protector
+CFLAGS_mem_encrypt_identity.o := $(PIE_CFLAGS)
+CFLAGS_pti.o := $(PIE_CFLAGS)
CFLAGS_fault.o := -I $(srctree)/$(src)/../include/asm/trace
--
2.43.0.429.g432eaa2c6b-goog
next prev parent reply other threads:[~2024-01-25 11:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-25 11:28 [PATCH v2 00/17] x86: Confine early 1:1 mapped startup code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 01/17] x86/startup_64: Drop long return to initial_code pointer Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 02/17] x86/startup_64: Simplify calculation of initial page table address Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 03/17] x86/startup_64: Simplify CR4 handling in startup code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 04/17] x86/startup_64: Drop global variables to keep track of LA57 state Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 05/17] x86/startup_64: Simplify virtual switch on primary boot Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 06/17] x86/head64: Replace pointer fixups with PIE codegen Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 07/17] x86/head64: Simplify GDT/IDT initialization code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 08/17] asm-generic: Add special .pi.text section for position independent code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 09/17] x86: Move return_thunk to __pitext section Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 10/17] x86/head64: Move early startup code into __pitext Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 11/17] modpost: Warn about calls from __pitext into other text sections Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 12/17] x86/coco: Make cc_set_mask() static inline Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 13/17] x86/sev: Make all code reachable from 1:1 mapping __pitext Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 14/17] x86/sev: Avoid WARN() in early code Ard Biesheuvel
2024-01-25 11:28 ` Ard Biesheuvel [this message]
2024-01-25 11:28 ` [PATCH v2 16/17] x86/sev: Drop inline asm LEA instructions for RIP-relative references Ard Biesheuvel
2024-01-25 20:46 ` Kevin Loughlin
2024-01-25 23:24 ` Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 17/17] x86/startup_64: Don't bother setting up GS before the kernel is mapped Ard Biesheuvel
2024-01-25 22:23 ` [PATCH v2 00/17] x86: Confine early 1:1 mapped startup code Nathan Chancellor
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