From: Ross Philipson <ross.philipson@oracle.com> To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, kexec@lists.infradead.org, linux-efi@vger.kernel.org Cc: ross.philipson@oracle.com, dpsmith@apertussolutions.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, ardb@kernel.org, mjg59@srcf.ucam.org, James.Bottomley@hansenpartnership.com, peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, luto@amacapital.net, nivedita@alum.mit.edu, herbert@gondor.apana.org.au, davem@davemloft.net, kanth.ghatraju@oracle.com, trenchboot-devel@googlegroups.com Subject: [PATCH v8 01/15] x86/boot: Place kernel_info at a fixed offset Date: Wed, 14 Feb 2024 14:18:33 -0800 [thread overview] Message-ID: <20240214221847.2066632-2-ross.philipson@oracle.com> (raw) In-Reply-To: <20240214221847.2066632-1-ross.philipson@oracle.com> From: Arvind Sankar <nivedita@alum.mit.edu> There are use cases for storing the offset of a symbol in kernel_info. For example, the trenchboot series [0] needs to store the offset of the Measured Launch Environment header in kernel_info. Since commit (note: commit ID from tip/master) commit 527afc212231 ("x86/boot: Check that there are no run-time relocations") run-time relocations are not allowed in the compressed kernel, so simply using the symbol in kernel_info, as .long symbol will cause a linker error because this is not position-independent. With kernel_info being a separate object file and in a different section from startup_32, there is no way to calculate the offset of a symbol from the start of the image in a position-independent way. To enable such use cases, put kernel_info into its own section which is placed at a predetermined offset (KERNEL_INFO_OFFSET) via the linker script. This will allow calculating the symbol offset in a position-independent way, by adding the offset from the start of kernel_info to KERNEL_INFO_OFFSET. Ensure that kernel_info is aligned, and use the SYM_DATA.* macros instead of bare labels. This stores the size of the kernel_info structure in the ELF symbol table. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Cc: Ross Philipson <ross.philipson@oracle.com> Signed-off-by: Ross Philipson <ross.philipson@oracle.com> --- arch/x86/boot/compressed/kernel_info.S | 19 +++++++++++++++---- arch/x86/boot/compressed/kernel_info.h | 12 ++++++++++++ arch/x86/boot/compressed/vmlinux.lds.S | 6 ++++++ 3 files changed, 33 insertions(+), 4 deletions(-) create mode 100644 arch/x86/boot/compressed/kernel_info.h diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S index f818ee8fba38..c18f07181dd5 100644 --- a/arch/x86/boot/compressed/kernel_info.S +++ b/arch/x86/boot/compressed/kernel_info.S @@ -1,12 +1,23 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> #include <asm/bootparam.h> +#include "kernel_info.h" - .section ".rodata.kernel_info", "a" +/* + * If a field needs to hold the offset of a symbol from the start + * of the image, use the macro below, eg + * .long rva(symbol) + * This will avoid creating run-time relocations, which are not + * allowed in the compressed kernel. + */ + +#define rva(X) (((X) - kernel_info) + KERNEL_INFO_OFFSET) - .global kernel_info + .section ".rodata.kernel_info", "a" -kernel_info: + .balign 16 +SYM_DATA_START(kernel_info) /* Header, Linux top (structure). */ .ascii "LToP" /* Size. */ @@ -19,4 +30,4 @@ kernel_info: kernel_info_var_len_data: /* Empty for time being... */ -kernel_info_end: +SYM_DATA_END_LABEL(kernel_info, SYM_L_LOCAL, kernel_info_end) diff --git a/arch/x86/boot/compressed/kernel_info.h b/arch/x86/boot/compressed/kernel_info.h new file mode 100644 index 000000000000..c127f84aec63 --- /dev/null +++ b/arch/x86/boot/compressed/kernel_info.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BOOT_COMPRESSED_KERNEL_INFO_H +#define BOOT_COMPRESSED_KERNEL_INFO_H + +#ifdef CONFIG_X86_64 +#define KERNEL_INFO_OFFSET 0x500 +#else /* 32-bit */ +#define KERNEL_INFO_OFFSET 0x100 +#endif + +#endif /* BOOT_COMPRESSED_KERNEL_INFO_H */ diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 083ec6d7722a..718c52f3f1e6 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -7,6 +7,7 @@ OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT) #include <asm/cache.h> #include <asm/page_types.h> +#include "kernel_info.h" #ifdef CONFIG_X86_64 OUTPUT_ARCH(i386:x86-64) @@ -27,6 +28,11 @@ SECTIONS HEAD_TEXT _ehead = . ; } + .rodata.kernel_info KERNEL_INFO_OFFSET : { + *(.rodata.kernel_info) + } + ASSERT(ABSOLUTE(kernel_info) == KERNEL_INFO_OFFSET, "kernel_info at bad address!") + .rodata..compressed : { *(.rodata..compressed) } -- 2.39.3 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
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From: Ross Philipson <ross.philipson@oracle.com> To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, kexec@lists.infradead.org, linux-efi@vger.kernel.org Cc: ross.philipson@oracle.com, dpsmith@apertussolutions.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, ardb@kernel.org, mjg59@srcf.ucam.org, James.Bottomley@hansenpartnership.com, peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, luto@amacapital.net, nivedita@alum.mit.edu, herbert@gondor.apana.org.au, davem@davemloft.net, kanth.ghatraju@oracle.com, trenchboot-devel@googlegroups.com Subject: [PATCH v8 01/15] x86/boot: Place kernel_info at a fixed offset Date: Wed, 14 Feb 2024 14:18:33 -0800 [thread overview] Message-ID: <20240214221847.2066632-2-ross.philipson@oracle.com> (raw) In-Reply-To: <20240214221847.2066632-1-ross.philipson@oracle.com> From: Arvind Sankar <nivedita@alum.mit.edu> There are use cases for storing the offset of a symbol in kernel_info. For example, the trenchboot series [0] needs to store the offset of the Measured Launch Environment header in kernel_info. Since commit (note: commit ID from tip/master) commit 527afc212231 ("x86/boot: Check that there are no run-time relocations") run-time relocations are not allowed in the compressed kernel, so simply using the symbol in kernel_info, as .long symbol will cause a linker error because this is not position-independent. With kernel_info being a separate object file and in a different section from startup_32, there is no way to calculate the offset of a symbol from the start of the image in a position-independent way. To enable such use cases, put kernel_info into its own section which is placed at a predetermined offset (KERNEL_INFO_OFFSET) via the linker script. This will allow calculating the symbol offset in a position-independent way, by adding the offset from the start of kernel_info to KERNEL_INFO_OFFSET. Ensure that kernel_info is aligned, and use the SYM_DATA.* macros instead of bare labels. This stores the size of the kernel_info structure in the ELF symbol table. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Cc: Ross Philipson <ross.philipson@oracle.com> Signed-off-by: Ross Philipson <ross.philipson@oracle.com> --- arch/x86/boot/compressed/kernel_info.S | 19 +++++++++++++++---- arch/x86/boot/compressed/kernel_info.h | 12 ++++++++++++ arch/x86/boot/compressed/vmlinux.lds.S | 6 ++++++ 3 files changed, 33 insertions(+), 4 deletions(-) create mode 100644 arch/x86/boot/compressed/kernel_info.h diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S index f818ee8fba38..c18f07181dd5 100644 --- a/arch/x86/boot/compressed/kernel_info.S +++ b/arch/x86/boot/compressed/kernel_info.S @@ -1,12 +1,23 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> #include <asm/bootparam.h> +#include "kernel_info.h" - .section ".rodata.kernel_info", "a" +/* + * If a field needs to hold the offset of a symbol from the start + * of the image, use the macro below, eg + * .long rva(symbol) + * This will avoid creating run-time relocations, which are not + * allowed in the compressed kernel. + */ + +#define rva(X) (((X) - kernel_info) + KERNEL_INFO_OFFSET) - .global kernel_info + .section ".rodata.kernel_info", "a" -kernel_info: + .balign 16 +SYM_DATA_START(kernel_info) /* Header, Linux top (structure). */ .ascii "LToP" /* Size. */ @@ -19,4 +30,4 @@ kernel_info: kernel_info_var_len_data: /* Empty for time being... */ -kernel_info_end: +SYM_DATA_END_LABEL(kernel_info, SYM_L_LOCAL, kernel_info_end) diff --git a/arch/x86/boot/compressed/kernel_info.h b/arch/x86/boot/compressed/kernel_info.h new file mode 100644 index 000000000000..c127f84aec63 --- /dev/null +++ b/arch/x86/boot/compressed/kernel_info.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BOOT_COMPRESSED_KERNEL_INFO_H +#define BOOT_COMPRESSED_KERNEL_INFO_H + +#ifdef CONFIG_X86_64 +#define KERNEL_INFO_OFFSET 0x500 +#else /* 32-bit */ +#define KERNEL_INFO_OFFSET 0x100 +#endif + +#endif /* BOOT_COMPRESSED_KERNEL_INFO_H */ diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 083ec6d7722a..718c52f3f1e6 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -7,6 +7,7 @@ OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT) #include <asm/cache.h> #include <asm/page_types.h> +#include "kernel_info.h" #ifdef CONFIG_X86_64 OUTPUT_ARCH(i386:x86-64) @@ -27,6 +28,11 @@ SECTIONS HEAD_TEXT _ehead = . ; } + .rodata.kernel_info KERNEL_INFO_OFFSET : { + *(.rodata.kernel_info) + } + ASSERT(ABSOLUTE(kernel_info) == KERNEL_INFO_OFFSET, "kernel_info at bad address!") + .rodata..compressed : { *(.rodata..compressed) } -- 2.39.3
next prev parent reply other threads:[~2024-02-14 22:32 UTC|newest] Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-14 22:18 [PATCH v8 00/15] x86: Trenchboot secure dynamic launch Linux kernel support Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` Ross Philipson [this message] 2024-02-14 22:18 ` [PATCH v8 01/15] x86/boot: Place kernel_info at a fixed offset Ross Philipson 2024-02-15 7:56 ` Ard Biesheuvel 2024-02-15 7:56 ` Ard Biesheuvel 2024-02-15 10:56 ` Daniel Kiper 2024-02-15 10:56 ` Daniel Kiper 2024-03-21 13:45 ` Daniel P. Smith 2024-03-21 13:45 ` Daniel P. Smith 2024-03-22 14:18 ` H. Peter Anvin 2024-03-22 14:18 ` H. Peter Anvin 2024-03-23 1:33 ` Daniel P. Smith 2024-03-23 1:33 ` Daniel P. Smith 2024-02-14 22:18 ` [PATCH v8 02/15] Documentation/x86: Secure Launch kernel documentation Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 03/15] x86: Secure Launch Kconfig Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 7:59 ` Ard Biesheuvel 2024-02-15 7:59 ` Ard Biesheuvel 2024-02-15 22:20 ` ross.philipson 2024-02-15 22:20 ` ross.philipson 2024-02-14 22:18 ` [PATCH v8 04/15] x86: Secure Launch Resource Table header file Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 8:08 ` Ard Biesheuvel 2024-02-15 8:08 ` Ard Biesheuvel 2024-02-22 2:03 ` Andrew Cooper 2024-02-22 2:03 ` Andrew Cooper 2024-02-22 2:10 ` ross.philipson 2024-02-22 2:10 ` ross.philipson 2024-02-22 17:49 ` ross.philipson 2024-02-22 17:49 ` ross.philipson 2024-03-29 22:38 ` Kim Phillips 2024-03-29 22:38 ` Kim Phillips 2024-03-29 22:38 ` Kim Phillips 2024-03-29 22:38 ` Kim Phillips 2024-03-29 22:38 ` Kim Phillips 2024-03-29 22:38 ` Kim Phillips 2024-04-01 18:25 ` ross.philipson 2024-04-01 18:25 ` ross.philipson 2024-02-14 22:18 ` [PATCH v8 05/15] x86: Secure Launch main " Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 06/15] x86: Add early SHA support for Secure Launch early measurements Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 8:17 ` Ard Biesheuvel 2024-02-15 8:17 ` Ard Biesheuvel 2024-02-22 3:04 ` Andrew Cooper 2024-02-22 3:04 ` Andrew Cooper 2024-02-22 9:34 ` Ard Biesheuvel 2024-02-22 9:34 ` Ard Biesheuvel 2024-02-22 12:30 ` Andrew Cooper 2024-02-22 12:30 ` Andrew Cooper 2024-02-23 9:27 ` Ard Biesheuvel 2024-02-23 9:27 ` Ard Biesheuvel 2024-02-23 16:42 ` Andrew Cooper 2024-02-23 16:42 ` Andrew Cooper 2024-02-23 17:54 ` Eric Biggers 2024-02-23 17:54 ` Eric Biggers 2024-02-23 18:20 ` Andrew Cooper 2024-02-23 18:20 ` Andrew Cooper 2024-02-23 18:30 ` Eric Biggers 2024-02-23 18:30 ` Eric Biggers 2024-04-03 16:32 ` Andy Lutomirski 2024-04-03 16:32 ` Andy Lutomirski 2024-04-03 23:56 ` Eric Biggers 2024-04-03 23:56 ` Eric Biggers 2024-04-04 4:55 ` ross.philipson 2024-04-04 4:55 ` ross.philipson 2024-04-04 14:55 ` Jarkko Sakkinen 2024-04-04 14:55 ` Jarkko Sakkinen 2024-02-14 22:18 ` [PATCH v8 07/15] x86: Secure Launch kernel early boot stub Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 8:29 ` Ard Biesheuvel 2024-02-15 8:29 ` Ard Biesheuvel 2024-02-15 22:26 ` ross.philipson 2024-02-15 22:26 ` ross.philipson 2024-02-14 22:18 ` [PATCH v8 08/15] x86: Secure Launch kernel late " Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 09/15] x86: Secure Launch SMP bringup support Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 10/15] kexec: Secure Launch kexec SEXIT support Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 11/15] reboot: Secure Launch SEXIT support on reboot paths Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 12/15] tpm: Add ability to set the preferred locality the TPM chip uses Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 13/15] tpm: Add sysfs interface to allow setting and querying the preferred locality Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-14 22:18 ` [PATCH v8 14/15] x86: Secure Launch late initcall platform module Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 8:40 ` Ard Biesheuvel 2024-02-15 8:40 ` Ard Biesheuvel 2024-02-22 13:57 ` Daniel P. Smith 2024-02-22 13:57 ` Daniel P. Smith 2024-02-23 9:36 ` Ard Biesheuvel 2024-02-23 9:36 ` Ard Biesheuvel 2024-03-21 14:11 ` Daniel P. Smith 2024-03-21 14:11 ` Daniel P. Smith 2024-02-16 1:53 ` kernel test robot 2024-02-16 1:53 ` kernel test robot 2024-02-17 7:53 ` kernel test robot 2024-02-17 7:53 ` kernel test robot 2024-02-14 22:18 ` [PATCH v8 15/15] x86: EFI stub DRTM launch support for Secure Launch Ross Philipson 2024-02-14 22:18 ` Ross Philipson 2024-02-15 9:01 ` Ard Biesheuvel 2024-02-15 9:01 ` Ard Biesheuvel 2024-02-21 20:17 ` ross.philipson 2024-02-21 20:17 ` ross.philipson 2024-02-21 20:37 ` H. Peter Anvin 2024-02-21 20:37 ` H. Peter Anvin 2024-02-21 23:24 ` Ard Biesheuvel 2024-02-21 23:24 ` Ard Biesheuvel 2024-02-17 7:31 ` kernel test robot 2024-02-17 7:31 ` kernel test robot 2024-02-17 20:06 ` kernel test robot 2024-02-17 20:06 ` kernel test robot
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