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From: Ard Biesheuvel <ardb+git@google.com>
To: linux-kernel@vger.kernel.org
Cc: linux-efi@vger.kernel.org, x86@kernel.org,
	 Ard Biesheuvel <ardb@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Ingo Molnar <mingo@kernel.org>,
	 Dionna Amalie Glaze <dionnaglaze@google.com>,
	Kevin Loughlin <kevinloughlin@google.com>,
	 Tom Lendacky <thomas.lendacky@amd.com>
Subject: [RFT PATCH v3 20/21] x86/boot: Revert "Reject absolute references in .head.text"
Date: Mon, 12 May 2025 21:08:55 +0200	[thread overview]
Message-ID: <20250512190834.332684-43-ardb+git@google.com> (raw)
In-Reply-To: <20250512190834.332684-23-ardb+git@google.com>

From: Ard Biesheuvel <ardb@kernel.org>

This reverts commit faf0ed487415f76fe4acf7980ce360901f5e1698.

The startup code is checked directly for the absence of absolute symbol
references, so checking the .head.text section in the relocs tool is no
longer needed.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/x86/tools/relocs.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 5778bc498415..e5a2b9a912d1 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -740,10 +740,10 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
 static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 		      const char *symname)
 {
-	int headtext = !strcmp(sec_name(sec->shdr.sh_info), ".head.text");
 	unsigned r_type = ELF64_R_TYPE(rel->r_info);
 	ElfW(Addr) offset = rel->r_offset;
 	int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
+
 	if (sym->st_shndx == SHN_UNDEF)
 		return 0;
 
@@ -783,12 +783,6 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
 			break;
 		}
 
-		if (headtext) {
-			die("Absolute reference to symbol '%s' not permitted in .head.text\n",
-			    symname);
-			break;
-		}
-
 		/*
 		 * Relocation offsets for 64 bit kernels are output
 		 * as 32 bits and sign extended back to 64 bits when
-- 
2.49.0.1045.g170613ef41-goog


  parent reply	other threads:[~2025-05-12 19:12 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-12 19:08 [RFT PATCH v3 00/21] x86: strict separation of startup code Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 01/21] x86/sev: Separate MSR and GHCB based snp_cpuid() via a callback Ard Biesheuvel
2025-05-15  7:22   ` Ingo Molnar
2025-05-15 10:24     ` Ard Biesheuvel
2025-05-15 15:18       ` Ingo Molnar
2025-05-15 11:10   ` Borislav Petkov
2025-05-15 14:22     ` Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 02/21] x86/sev: Use MSR protocol for remapping SVSM calling area Ard Biesheuvel
2025-05-15 16:43   ` Borislav Petkov
2025-05-12 19:08 ` [RFT PATCH v3 03/21] x86/sev: Use MSR protocol only for early SVSM PVALIDATE call Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 04/21] x86/sev: Run RMPADJUST on SVSM calling area page to test VMPL Ard Biesheuvel
2025-05-20  9:44   ` Borislav Petkov
2025-05-12 19:08 ` [RFT PATCH v3 05/21] x86/sev: Move GHCB page based HV communication out of startup code Ard Biesheuvel
2025-05-20 11:38   ` Borislav Petkov
2025-05-20 11:49     ` Ard Biesheuvel
2025-05-20 13:58       ` Borislav Petkov
2025-05-12 19:08 ` [RFT PATCH v3 06/21] x86/sev: Avoid global variable to store virtual address of SVSM area Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 07/21] x86/sev: Move MSR save/restore out of early page state change helper Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 08/21] x86/sev: Share implementation of MSR-based page state change Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 09/21] x86/sev: Pass SVSM calling area down to early page state change API Ard Biesheuvel
2025-05-13 13:55   ` Ard Biesheuvel
2025-05-13 13:58     ` Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 10/21] x86/sev: Use boot SVSM CA for all startup and init code Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 11/21] x86/boot: Drop redundant RMPADJUST in SEV SVSM presence check Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 12/21] x86/sev: Unify SEV-SNP hypervisor feature check Ard Biesheuvel
2025-05-30 11:16   ` Borislav Petkov
2025-05-30 14:28     ` Ard Biesheuvel
2025-05-30 16:08       ` Borislav Petkov
2025-05-30 16:12         ` Ard Biesheuvel
2025-05-30 16:55           ` Borislav Petkov
2025-05-12 19:08 ` [RFT PATCH v3 13/21] x86/sev: Provide PIC aliases for SEV related data objects Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 14/21] x86/boot: Provide PIC aliases for 5-level paging related constants Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 15/21] x86/sev: Move __sev_[get|put]_ghcb() into separate noinstr object Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 16/21] x86/sev: Export startup routines for later use Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 17/21] x86/boot: Create a confined code area for startup code Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 18/21] x86/boot: Move startup code out of __head section Ard Biesheuvel
2025-05-12 19:08 ` [RFT PATCH v3 19/21] x86/boot: Disallow absolute symbol references in startup code Ard Biesheuvel
2025-05-12 19:08 ` Ard Biesheuvel [this message]
2025-06-01  9:39   ` [RFT PATCH v3 20/21] x86/boot: Revert "Reject absolute references in .head.text" Borislav Petkov
2025-05-12 19:08 ` [RFT PATCH v3 21/21] x86/boot: Get rid of the .head.text section Ard Biesheuvel
2025-05-12 19:17 ` [RFT PATCH v3 00/21] x86: strict separation of startup code Borislav Petkov
2025-05-13 10:02   ` Ingo Molnar
2025-05-13 10:12     ` Borislav Petkov
2025-05-13 11:22       ` Ingo Molnar
2025-05-13 14:16         ` Borislav Petkov
2025-05-13 15:01           ` Ard Biesheuvel
2025-05-13 16:44             ` Borislav Petkov
2025-05-13 21:31               ` Ard Biesheuvel
2025-05-14  6:32             ` Ingo Molnar
2025-05-14  7:41               ` Ard Biesheuvel
2025-05-15  7:17                 ` Ingo Molnar
2025-05-14  6:20           ` Ingo Molnar
2025-05-14  8:17             ` Borislav Petkov
2025-05-14  8:21             ` Borislav Petkov
2025-05-14  9:54             ` Thomas Gleixner
2025-05-14 17:21 ` Borislav Petkov
2025-05-14 17:37   ` Ard Biesheuvel
2025-05-14 18:53     ` Borislav Petkov

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