[PATCH v2 1/7] riscv: Add kexec trampoline text section to vmlinux.lds.S
| Newsgroups | org.infradead.lists.kvm-riscv,org.infradead.lists.kexec,org.infradead.lists.linux-riscv,org.kernel.vger.kvm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Fangyu Yu <[email protected]> When CONFIG_KEXEC_CORE is enabled, add a dedicated .kexec.tramp.text area to the RISC-V kernel linker script. This introduces a KEXEC_TRAMP_TEXT linker snippet in image-vars.h and uses it from vmlinux.lds.S to: - align both the start and the end to PAGE_SIZE - define __kexec_tramp_text_start/__kexec_tramp_text_end - KEEP all .kexec.tramp.text* input sections - ASSERT the trampoline text fits within one page The end-of-section page alignment guarantees that the trampoline page, which is later identity-mapped as PAGE_KERNEL_EXEC, contains nothing but the trampoline code and padding (no shared neighbour data). When kexec is disabled, KEXEC_TRAMP_TEXT expands to nothing. Signed-off-by: Fangyu Yu <[email protected]> --- arch/riscv/kernel/image-vars.h | 14 ++++++++++++++ arch/riscv/kernel/vmlinux.lds.S | 1 + 2 files changed, 15 insertions(+) diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h index 3bd9d06a8b8f..35ee3f059afa 100644 --- a/arch/riscv/kernel/image-vars.h +++ b/arch/riscv/kernel/image-vars.h @@ -34,4 +34,18 @@ __efistub_sysfb_primary_display = sysfb_primary_display; #endif +#ifdef CONFIG_KEXEC_CORE +#define KEXEC_TRAMP_TEXT \ + . = ALIGN(PAGE_SIZE); \ + __kexec_tramp_text_start = .; \ + KEEP(*(.kexec.tramp.text)) \ + KEEP(*(.kexec.tramp.text.*)) \ + __kexec_tramp_text_end = .; \ + ASSERT((__kexec_tramp_text_end - __kexec_tramp_text_start) <= PAGE_SIZE, \ + ".kexec.tramp.text exceeds 4K"); \ + . = ALIGN(PAGE_SIZE); +#else +#define KEXEC_TRAMP_TEXT /* nothing */ +#endif + #endif /* __RISCV_KERNEL_IMAGE_VARS_H */ diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 1f4f8496941a..fc7758e5b819 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -41,6 +41,7 @@ SECTIONS ENTRY_TEXT IRQENTRY_TEXT SOFTIRQENTRY_TEXT + KEXEC_TRAMP_TEXT _etext = .; } -- 2.50.1 -- kvm-riscv mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kvm-riscv