| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20241026171441.3047904-4-samuel.holland@sifive.com>
Date: Sat, 26 Oct 2024 10:13:55 -0700
From: Samuel Holland <samuel.holland@...ive.com>
To: Palmer Dabbelt <palmer@...belt.com>,
linux-kernel@...r.kernel.org,
linux-riscv@...ts.infradead.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Arnd Bergmann <arnd@...db.de>,
Alexandre Ghiti <alexghiti@...osinc.com>,
Samuel Holland <samuel.holland@...ive.com>
Subject: [PATCH 3/6] riscv: Support CONFIG_RELOCATABLE on NOMMU
Move relocate_kernel() out of the CONFIG_MMU block so it can be called
from the NOMMU version of setup_vm(). Set some offsets in kernel_map so
relocate_kernel() does not need to be modified. Relocatable NOMMU
kernels can be loaded to any physical memory address; they no longer
depend on CONFIG_PAGE_OFFSET.
Signed-off-by: Samuel Holland <samuel.holland@...ive.com>
---
arch/riscv/Kconfig | 2 +-
arch/riscv/include/asm/pgtable.h | 4 ++
arch/riscv/mm/init.c | 82 +++++++++++++++++---------------
3 files changed, 49 insertions(+), 39 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 62545946ecf4..4420419e7054 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -934,7 +934,7 @@ config PARAVIRT_TIME_ACCOUNTING
config RELOCATABLE
bool "Build a relocatable kernel"
- depends on MMU && 64BIT && !XIP_KERNEL
+ depends on 64BIT && !XIP_KERNEL
select MODULE_SECTIONS if MODULES
help
This builds a kernel as a Position Independent Executable (PIE),
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index e224ac66e635..d0190ee9b2e4 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -12,7 +12,11 @@
#include <asm/pgtable-bits.h>
#ifndef CONFIG_MMU
+#ifdef CONFIG_RELOCATABLE
+#define KERNEL_LINK_ADDR UL(0)
+#else
#define KERNEL_LINK_ADDR _AC(CONFIG_PAGE_OFFSET, UL)
+#endif
#define KERN_VIRT_SIZE (UL(-1))
#else
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 0e8c20adcd98..a74e28367f9f 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -307,6 +307,44 @@ static void __init setup_bootmem(void)
hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
}
+#ifdef CONFIG_RELOCATABLE
+extern unsigned long __rela_dyn_start, __rela_dyn_end;
+
+static void __init relocate_kernel(void)
+{
+ Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
+ /*
+ * This holds the offset between the linked virtual address and the
+ * relocated virtual address.
+ */
+ uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
+ /*
+ * This holds the offset between kernel linked virtual address and
+ * physical address.
+ */
+ uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
+
+ for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
+ Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
+ Elf64_Addr relocated_addr = rela->r_addend;
+
+ if (rela->r_info != R_RISCV_RELATIVE)
+ continue;
+
+ /*
+ * Make sure to not relocate vdso symbols like rt_sigreturn
+ * which are linked from the address 0 in vmlinux since
+ * vdso symbol addresses are actually used as an offset from
+ * mm->context.vdso in VDSO_OFFSET macro.
+ */
+ if (relocated_addr >= KERNEL_LINK_ADDR)
+ relocated_addr += reloc_offset;
+
+ *(Elf64_Addr *)addr = relocated_addr;
+ }
+}
+#endif /* CONFIG_RELOCATABLE */
+
#ifdef CONFIG_MMU
struct pt_alloc_ops pt_ops __meminitdata;
@@ -877,44 +915,6 @@ static __init void set_satp_mode(uintptr_t dtb_pa)
#error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
#endif
-#ifdef CONFIG_RELOCATABLE
-extern unsigned long __rela_dyn_start, __rela_dyn_end;
-
-static void __init relocate_kernel(void)
-{
- Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
- /*
- * This holds the offset between the linked virtual address and the
- * relocated virtual address.
- */
- uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
- /*
- * This holds the offset between kernel linked virtual address and
- * physical address.
- */
- uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
-
- for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
- Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
- Elf64_Addr relocated_addr = rela->r_addend;
-
- if (rela->r_info != R_RISCV_RELATIVE)
- continue;
-
- /*
- * Make sure to not relocate vdso symbols like rt_sigreturn
- * which are linked from the address 0 in vmlinux since
- * vdso symbol addresses are actually used as an offset from
- * mm->context.vdso in VDSO_OFFSET macro.
- */
- if (relocated_addr >= KERNEL_LINK_ADDR)
- relocated_addr += reloc_offset;
-
- *(Elf64_Addr *)addr = relocated_addr;
- }
-}
-#endif /* CONFIG_RELOCATABLE */
-
#ifdef CONFIG_XIP_KERNEL
static void __init create_kernel_page_table(pgd_t *pgdir,
__always_unused bool early)
@@ -1359,6 +1359,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
dtb_early_va = (void *)dtb_pa;
dtb_early_pa = dtb_pa;
+
+#ifdef CONFIG_RELOCATABLE
+ kernel_map.virt_addr = (uintptr_t)_start;
+ kernel_map.phys_addr = (uintptr_t)_start;
+ relocate_kernel();
+#endif
}
static inline void setup_vm_final(void)
--
2.45.1
Powered by blists - more mailing lists