From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org,
ebiederm@xmission.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, corbet@lwn.net,
catalin.marinas@arm.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org, maz@kernel.org,
james.morse@arm.com, vladimir.murzin@arm.com,
matthias.bgg@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com,
steve.capper@arm.com, rfontana@redhat.com, tglx@linutronix.de,
selindag@gmail.com, tyhicks@linux.microsoft.com
Subject: [PATCH v10 14/18] arm64: kexec: use ld script for relocation function
Date: Mon, 25 Jan 2021 14:19:19 -0500 [thread overview]
Message-ID: <20210125191923.1060122-15-pasha.tatashin@soleen.com> (raw)
In-Reply-To: <20210125191923.1060122-1-pasha.tatashin@soleen.com>
Currently, relocation code declares start and end variables
which are used to compute it size.
The better way to do this is to use ld script incited, and put relocation
function in its own section.
Soon, relocation function will share the same page with EL2 vectors. So,
proper marking is needed.
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
---
arch/arm64/include/asm/kexec.h | 4 ++++
arch/arm64/include/asm/sections.h | 1 +
arch/arm64/kernel/machine_kexec.c | 17 ++++++++---------
arch/arm64/kernel/relocate_kernel.S | 15 ++-------------
arch/arm64/kernel/vmlinux.lds.S | 19 +++++++++++++++++++
5 files changed, 34 insertions(+), 22 deletions(-)
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index 990185744148..7f4f9abdf049 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -90,6 +90,10 @@ static inline void crash_prepare_suspend(void) {}
static inline void crash_post_resume(void) {}
#endif
+#if defined(CONFIG_KEXEC_CORE)
+extern const char arm64_relocate_new_kernel[];
+#endif
+
/*
* kern_reloc_arg is passed to kernel relocation function as an argument.
* head kimage->head, allows to traverse through relocation segments.
diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h
index 8ff579361731..ae873eb22205 100644
--- a/arch/arm64/include/asm/sections.h
+++ b/arch/arm64/include/asm/sections.h
@@ -19,5 +19,6 @@ extern char __exittext_begin[], __exittext_end[];
extern char __irqentry_text_start[], __irqentry_text_end[];
extern char __mmuoff_data_start[], __mmuoff_data_end[];
extern char __entry_tramp_text_start[], __entry_tramp_text_end[];
+extern char __relocate_new_kernel_start[], __relocate_new_kernel_end[];
#endif /* __ASM_SECTIONS_H */
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 679db3f1e0c5..361a4d082093 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -20,13 +20,10 @@
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
+#include <asm/sections.h>
#include "cpu-reset.h"
-/* Global variables for the arm64_relocate_new_kernel routine. */
-extern const unsigned char arm64_relocate_new_kernel[];
-extern const unsigned long arm64_relocate_new_kernel_size;
-
/**
* kexec_image_info - For debugging output.
*/
@@ -78,13 +75,15 @@ int machine_kexec_post_load(struct kimage *kimage)
{
void *reloc_code = page_to_virt(kimage->control_code_page);
struct kern_reloc_arg *kern_reloc_arg = kexec_page_alloc(kimage);
+ long func_offset, reloc_size;
if (!kern_reloc_arg)
return -ENOMEM;
- memcpy(reloc_code, arm64_relocate_new_kernel,
- arm64_relocate_new_kernel_size);
- kimage->arch.kern_reloc = __pa(reloc_code);
+ func_offset = arm64_relocate_new_kernel - __relocate_new_kernel_start;
+ reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start;
+ memcpy(reloc_code, __relocate_new_kernel_start, reloc_size);
+ kimage->arch.kern_reloc = __pa(reloc_code) + func_offset;
kimage->arch.kern_reloc_arg = __pa(kern_reloc_arg);
kern_reloc_arg->head = kimage->head;
kern_reloc_arg->entry_addr = kimage->start;
@@ -92,9 +91,9 @@ int machine_kexec_post_load(struct kimage *kimage)
kexec_image_info(kimage);
/* Flush the reloc_code in preparation for its execution. */
- __flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size);
+ __flush_dcache_area(reloc_code, reloc_size);
flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code +
- arm64_relocate_new_kernel_size);
+ reloc_size);
__flush_dcache_area(kern_reloc_arg, sizeof(struct kern_reloc_arg));
return 0;
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index c92228aeddca..d2a4a0b0d76b 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -14,6 +14,7 @@
#include <asm/page.h>
#include <asm/sysreg.h>
+.pushsection ".kexec_relocate.text", "ax"
/*
* arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
*
@@ -75,16 +76,4 @@ SYM_CODE_START(arm64_relocate_new_kernel)
ldr x0, [x0, #KEXEC_KRELOC_KERN_ARG0] /* x0 = dtb address */
br x4
SYM_CODE_END(arm64_relocate_new_kernel)
-
-.align 3 /* To keep the 64-bit values below naturally aligned. */
-
-.Lcopy_end:
-.org KEXEC_CONTROL_PAGE_SIZE
-
-/*
- * arm64_relocate_new_kernel_size - Number of bytes to copy to the
- * control_code_page.
- */
-.globl arm64_relocate_new_kernel_size
-arm64_relocate_new_kernel_size:
- .quad .Lcopy_end - arm64_relocate_new_kernel
+.popsection
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 4c0b0c89ad59..33b0d3c9fd3b 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -12,6 +12,7 @@
#include <asm/cache.h>
#include <asm/hyp_image.h>
#include <asm/kernel-pgtable.h>
+#include <asm/kexec.h>
#include <asm/memory.h>
#include <asm/page.h>
@@ -82,6 +83,16 @@ jiffies = jiffies_64;
#define HIBERNATE_TEXT
#endif
+#ifdef CONFIG_KEXEC_CORE
+#define KEXEC_TEXT \
+ . = ALIGN(SZ_4K); \
+ __relocate_new_kernel_start = .; \
+ *(.kexec_relocate.text) \
+ __relocate_new_kernel_end = .;
+#else
+#define KEXEC_TEXT
+#endif
+
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
#define TRAMP_TEXT \
. = ALIGN(PAGE_SIZE); \
@@ -142,6 +153,7 @@ SECTIONS
HYPERVISOR_TEXT
IDMAP_TEXT
HIBERNATE_TEXT
+ KEXEC_TEXT
TRAMP_TEXT
*(.fixup)
*(.gnu.warning)
@@ -316,3 +328,10 @@ ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE,
* If padding is applied before .head.text, virt<->phys conversions will fail.
*/
ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned")
+
+#ifdef CONFIG_KEXEC_CORE
+/* kexec relocation code should fit into one KEXEC_CONTROL_PAGE_SIZE */
+ASSERT(__relocate_new_kernel_end - (__relocate_new_kernel_start & ~(SZ_4K - 1))
+ <= SZ_4K, "kexec relocation code is too big or misaligned")
+ASSERT(KEXEC_CONTROL_PAGE_SIZE >= SZ_4K, "KEXEC_CONTROL_PAGE_SIZE is brokern")
+#endif
--
2.25.1
next prev parent reply other threads:[~2021-01-25 19:20 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 19:19 [PATCH v10 00/18] arm64: MMU enabled kexec relocation Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 01/18] arm64: kexec: make dtb_mem always enabled Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 02/18] arm64: hibernate: variable pudp is used instead of pd4dp Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 03/18] arm64: hibernate: move page handling function to new trans_pgd.c Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 04/18] arm64: trans_pgd: make trans_pgd_map_page generic Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 05/18] arm64: trans_pgd: pass allocator trans_pgd_create_copy Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 06/18] arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 07/18] arm64: mm: Always update TCR_EL1 from __cpu_set_tcr_t0sz() Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 08/18] arm64: trans_pgd: hibernate: idmap the single page that holds the copy page routines Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 09/18] arm64: kexec: move relocation function setup Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 10/18] arm64: kexec: call kexec_image_info only once Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 11/18] arm64: kexec: arm64_relocate_new_kernel clean-ups and optimizations Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 12/18] arm64: kexec: arm64_relocate_new_kernel don't use x0 as temp Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 13/18] arm64: kexec: add expandable argument to relocation function Pavel Tatashin
2021-01-25 19:19 ` Pavel Tatashin [this message]
2021-01-25 19:19 ` [PATCH v10 15/18] arm64: kexec: kexec may require EL2 vectors Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 16/18] arm64: kexec: configure trans_pgd page table for kexec Pavel Tatashin
2021-01-26 0:21 ` Pavel Tatashin
2021-01-27 16:42 ` Tyler Hicks
2021-01-27 16:47 ` Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 17/18] arm64: kexec: enable MMU during kexec relocation Pavel Tatashin
2021-01-25 19:19 ` [PATCH v10 18/18] arm64: kexec: remove head from relocation argument Pavel Tatashin
2021-01-26 22:58 ` [PATCH v10 00/18] arm64: MMU enabled kexec relocation Will Deacon
2021-01-26 23:05 ` Pavel Tatashin
2021-01-26 23:11 ` Will Deacon
2021-01-27 15:59 ` (subset) " Will Deacon
2021-01-27 16:12 ` Pavel Tatashin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210125191923.1060122-15-pasha.tatashin@soleen.com \
--to=pasha.tatashin@soleen.com \
--cc=catalin.marinas@arm.com \
--cc=corbet@lwn.net \
--cc=ebiederm@xmission.com \
--cc=james.morse@arm.com \
--cc=jmorris@namei.org \
--cc=kexec@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mark.rutland@arm.com \
--cc=matthias.bgg@gmail.com \
--cc=maz@kernel.org \
--cc=rfontana@redhat.com \
--cc=sashal@kernel.org \
--cc=selindag@gmail.com \
--cc=steve.capper@arm.com \
--cc=tglx@linutronix.de \
--cc=tyhicks@linux.microsoft.com \
--cc=vladimir.murzin@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox