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AJvYcCW9GjQemtVITi4q0UmHngaIqQGjmtrpwXZ8kdDZ7nvD9JkAP5oJFYARLBfDvRUcBgULTqOgo+osoMfBZZE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywq8nlpwYaExEvQyyYiKeSyVz8RxciA4jC9CbB6SuBi+JscLoBl 1uUBRRstXwTe+vf0dJVwv1qoHBkbVY1ABDrEyiLt9v2vxAatVddKmXuBeGtxtAvfUVMlTg== X-Google-Smtp-Source: AGHT+IG8l7xPrwiQoCJNQ/ba3EMloi9V99YK0VEhh/KbnKIqVODzSQX4+kTe9p6XHA3xEE581cvXY/7/ X-Received: from palermo.c.googlers.com ([fda3:e722:ac3:cc00:7b:198d:ac11:8138]) (user=ardb job=sendgmr) by 2002:a25:fc20:0:b0:e25:17cb:352e with SMTP id 3f1490d57ef6-e2517cb37ebmr1573276.9.1727276563646; Wed, 25 Sep 2024 08:02:43 -0700 (PDT) Date: Wed, 25 Sep 2024 17:01:21 +0200 In-Reply-To: <20240925150059.3955569-30-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240925150059.3955569-30-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=2665; i=ardb@kernel.org; h=from:subject; bh=aFznGPhrIJfcYbFW/zJm7PxtyN4XPqpBJvJpRLs7DOQ=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIe2L6smrOU/sUlwy2LTW237rV4pUONJ8T3XtdLO2DQ3bj 80/F1nfUcrCIMbBICumyCIw+++7nacnStU6z5KFmcPKBDKEgYtTACYyyZHhn8LWprti0g+tdKf9 /bStUjGJXy/+qc4H120n962eP03h1yKG/wHHj7aK75zgynumw7x0V1PPmh2muXNy98WcvvZ74cO kJi4A X-Mailer: git-send-email 2.46.0.792.g87dc391469-goog Message-ID: <20240925150059.3955569-51-ardb+git@google.com> Subject: [RFC PATCH 21/28] x86/head: Use PIC-compatible symbol references in startup code From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: Ard Biesheuvel , x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Uros Bizjak , Dennis Zhou , Tejun Heo , Christoph Lameter , Mathieu Desnoyers , Paolo Bonzini , Vitaly Kuznetsov , Juergen Gross , Boris Ostrovsky , Greg Kroah-Hartman , Arnd Bergmann , Masahiro Yamada , Kees Cook , Nathan Chancellor , Keith Packard , Justin Stitt , Josh Poimboeuf , Arnaldo Carvalho de Melo , Namhyung Kim , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , linux-doc@vger.kernel.org, linux-pm@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, linux-efi@vger.kernel.org, linux-arch@vger.kernel.org, linux-sparse@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-perf-users@vger.kernel.org, rust-for-linux@vger.kernel.org, llvm@lists.linux.dev From: Ard Biesheuvel Use RIP-relative symbol references to make them compatible with running the linker in PIE mode. Signed-off-by: Ard Biesheuvel --- arch/x86/kernel/head_64.S | 14 +++++++++----- arch/x86/kernel/relocate_kernel_64.S | 6 ++++-- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index db71cf64204b..cc2fec3de4b7 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -182,8 +182,9 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) xorl %r15d, %r15d /* Derive the runtime physical address of init_top_pgt[] */ - movq phys_base(%rip), %rax - addq $(init_top_pgt - __START_KERNEL_map), %rax + leaq init_top_pgt(%rip), %rax + subq $__START_KERNEL_map, %rax + addq phys_base(%rip), %rax /* * Retrieve the modifier (SME encryption mask if SME is active) to be @@ -314,7 +315,8 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL) .Lsetup_cpu: /* Get the per cpu offset for the given CPU# which is in ECX */ - movq __per_cpu_offset(,%rcx,8), %rdx + leaq __per_cpu_offset(%rip), %rdx + movq (%rdx,%rcx,8), %rdx #else xorl %edx, %edx /* zero-extended to clear all of RDX */ #endif /* CONFIG_SMP */ @@ -325,7 +327,8 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL) * * RDX contains the per-cpu offset */ - movq pcpu_hot + X86_current_task(%rdx), %rax + leaq pcpu_hot + X86_current_task(%rip), %rax + movq (%rax,%rdx), %rax movq TASK_threadsp(%rax), %rsp /* @@ -346,7 +349,8 @@ SYM_INNER_LABEL(common_startup_64, SYM_L_LOCAL) */ subq $16, %rsp movw $(GDT_SIZE-1), (%rsp) - leaq gdt_page(%rdx), %rax + leaq gdt_page(%rip), %rax + addq %rdx, %rax movq %rax, 2(%rsp) lgdt (%rsp) addq $16, %rsp diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index e9e88c342f75..cbfd0227ea3e 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -106,6 +106,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel) /* setup a new stack at the end of the physical control page */ lea PAGE_SIZE(%r8), %rsp + /* take the virtual address of virtual_mapped() before jumping */ + leaq virtual_mapped(%rip), %r14 + /* jump to identity mapped page */ addq $(identity_mapped - relocate_kernel), %r8 pushq %r8 @@ -225,8 +228,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) movq %rax, %cr3 lea PAGE_SIZE(%r8), %rsp call swap_pages - movq $virtual_mapped, %rax - pushq %rax + pushq %r14 ANNOTATE_UNRET_SAFE ret int3