From: Yousong Zhou <yszhou4tech@gmail.com>
Subject: MIPS: kexec: Accept command line parameters from userspace.
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
---
arch/mips/kernel/machine_kexec.c | 153 +++++++++++++++++++++++++++++++-----
arch/mips/kernel/machine_kexec.h | 20 +++++
arch/mips/kernel/relocate_kernel.S | 21 +++--
3 files changed, 167 insertions(+), 27 deletions(-)
create mode 100644 arch/mips/kernel/machine_kexec.h
--- a/arch/mips/kernel/machine_kexec.c
+++ b/arch/mips/kernel/machine_kexec.c
@@ -9,14 +9,11 @@
#include <linux/delay.h>
#include <linux/libfdt.h>
+#include <asm/bootinfo.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
-
-extern const unsigned char relocate_new_kernel[];
-extern const size_t relocate_new_kernel_size;
-
-extern unsigned long kexec_start_address;
-extern unsigned long kexec_indirection_page;
+#include <linux/uaccess.h>
+#include "machine_kexec.h"
static unsigned long reboot_code_buffer;
@@ -30,6 +27,101 @@ void (*_crash_smp_send_stop)(void) = NUL
void (*_machine_kexec_shutdown)(void) = NULL;
void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
+static void machine_kexec_print_args(void)
+{
+ unsigned long argc = (int)kexec_args[0];
+ int i;
+
+ pr_info("kexec_args[0] (argc): %lu\n", argc);
+ pr_info("kexec_args[1] (argv): %p\n", (void *)kexec_args[1]);
+ pr_info("kexec_args[2] (env ): %p\n", (void *)kexec_args[2]);
+ pr_info("kexec_args[3] (desc): %p\n", (void *)kexec_args[3]);
+
+ for (i = 0; i < argc; i++) {
+ pr_info("kexec_argv[%d] = %p, %s\n",
+ i, kexec_argv[i], kexec_argv[i]);
+ }
+}
+
+static void machine_kexec_init_argv(struct kimage *image)
+{
+ void __user *buf = NULL;
+ size_t bufsz;
+ size_t size;
+ int i;
+
+ bufsz = 0;
+ for (i = 0; i < image->nr_segments; i++) {
+ struct kexec_segment *seg;
+
+ seg = &image->segment[i];
+ if (seg->bufsz < 6)
+ continue;
+
+ if (strncmp((char *) seg->buf, "kexec ", 6))
+ continue;
+
+ buf = seg->buf;
+ bufsz = seg->bufsz;
+ break;
+ }
+
+ if (!buf)
+ return;
+
+ size = KEXEC_COMMAND_LINE_SIZE;
+ size = min(size, bufsz);
+ if (size < bufsz)
+ pr_warn("kexec command line truncated to %zd bytes\n", size);
+
+ /* Copy to kernel space */
+ if (copy_from_user(kexec_argv_buf, buf, size))
+ pr_warn("kexec command line copy to kernel space failed\n");
+
+ kexec_argv_buf[size - 1] = 0;
+}
+
+static void machine_kexec_parse_argv(struct kimage *image)
+{
+ char *reboot_code_buffer;
+ int reloc_delta;
+ char *ptr;
+ int argc;
+ int i;
+
+ ptr = kexec_argv_buf;
+ argc = 0;
+
+ /*
+ * convert command line string to array of parameters
+ * (as bootloader does).
+ */
+ while (ptr && *ptr && (KEXEC_MAX_ARGC > argc)) {
+ if (*ptr == ' ') {
+ *ptr++ = '\0';
+ continue;
+ }
+
+ kexec_argv[argc++] = ptr;
+ ptr = strchr(ptr, ' ');
+ }
+
+ if (!argc)
+ return;
+
+ kexec_args[0] = argc;
+ kexec_args[1] = (unsigned long)kexec_argv;
+ kexec_args[2] = 0;
+ kexec_args[3] = 0;
+
+ reboot_code_buffer = page_address(image->control_code_page);
+ reloc_delta = reboot_code_buffer - (char *)kexec_relocate_new_kernel;
+
+ kexec_args[1] += reloc_delta;
+ for (i = 0; i < argc; i++)
+ kexec_argv[i] += reloc_delta;
+}
+
static void kexec_image_info(const struct kimage *kimage)
{
unsigned long i;
@@ -99,6 +191,18 @@ machine_kexec_prepare(struct kimage *kim
#endif
kexec_image_info(kimage);
+ /*
+ * Whenever arguments passed from kexec-tools, Init the arguments as
+ * the original ones to try avoiding booting failure.
+ */
+
+ kexec_args[0] = fw_arg0;
+ kexec_args[1] = fw_arg1;
+ kexec_args[2] = fw_arg2;
+ kexec_args[3] = fw_arg3;
+
+ machine_kexec_init_argv(kimage);
+ machine_kexec_parse_argv(kimage);
if (_machine_kexec_prepare)
return _machine_kexec_prepare(kimage);
@@ -161,7 +265,7 @@ machine_crash_shutdown(struct pt_regs *r
void kexec_nonboot_cpu_jump(void)
{
local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
- reboot_code_buffer + relocate_new_kernel_size);
+ reboot_code_buffer + KEXEC_RELOCATE_NEW_KERNEL_SIZE);
relocated_kexec_smp_wait(NULL);
}
@@ -199,7 +303,7 @@ void kexec_reboot(void)
* machine_kexec() CPU.
*/
local_flush_icache_range(reboot_code_buffer,
- reboot_code_buffer + relocate_new_kernel_size);
+ reboot_code_buffer + KEXEC_RELOCATE_NEW_KERNEL_SIZE);
do_kexec = (void *)reboot_code_buffer;
do_kexec();
@@ -212,10 +316,12 @@ machine_kexec(struct kimage *image)
unsigned long *ptr;
reboot_code_buffer =
- (unsigned long)page_address(image->control_code_page);
+ (unsigned long)page_address(image->control_code_page);
+ pr_info("reboot_code_buffer = %p\n", (void *)reboot_code_buffer);
kexec_start_address =
(unsigned long) phys_to_virt(image->start);
+ pr_info("kexec_start_address = %p\n", (void *)kexec_start_address);
if (image->type == KEXEC_TYPE_DEFAULT) {
kexec_indirection_page =
@@ -223,9 +329,19 @@ machine_kexec(struct kimage *image)
} else {
kexec_indirection_page = (unsigned long)&image->head;
}
+ pr_info("kexec_indirection_page = %p\n", (void *)kexec_indirection_page);
- memcpy((void*)reboot_code_buffer, relocate_new_kernel,
- relocate_new_kernel_size);
+ pr_info("Where is memcpy: %p\n", memcpy);
+ pr_info("kexec_relocate_new_kernel = %p, kexec_relocate_new_kernel_end = %p\n",
+ (void *)kexec_relocate_new_kernel, &kexec_relocate_new_kernel_end);
+ pr_info("Copy %lu bytes from %p to %p\n", KEXEC_RELOCATE_NEW_KERNEL_SIZE,
+ (void *)kexec_relocate_new_kernel, (void *)reboot_code_buffer);
+ memcpy((void*)reboot_code_buffer, kexec_relocate_new_kernel,
+ KEXEC_RELOCATE_NEW_KERNEL_SIZE);
+
+ pr_info("Before _print_args().\n");
+ machine_kexec_print_args();
+ pr_info("Before eval loop.\n");
/*
* The generic kexec code builds a page list with physical
@@ -256,7 +372,7 @@ machine_kexec(struct kimage *image)
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer +
- (void *)(kexec_smp_wait - relocate_new_kernel);
+ (void *)(kexec_smp_wait - kexec_relocate_new_kernel);
smp_wmb();
atomic_set(&kexec_ready_to_reboot, 1);
#endif
--- /dev/null
+++ b/arch/mips/kernel/machine_kexec.h
@@ -0,0 +1,20 @@
+#ifndef _MACHINE_KEXEC_H
+#define _MACHINE_KEXEC_H
+
+#ifndef __ASSEMBLY__
+extern const unsigned char kexec_relocate_new_kernel[];
+extern unsigned long kexec_relocate_new_kernel_end;
+extern unsigned long kexec_start_address;
+extern unsigned long kexec_indirection_page;
+
+extern char kexec_argv_buf[];
+extern char *kexec_argv[];
+
+#define KEXEC_RELOCATE_NEW_KERNEL_SIZE ((unsigned long)&kexec_relocate_new_kernel_end - (unsigned long)kexec_relocate_new_kernel)
+#endif /* !__ASSEMBLY__ */
+
+#define KEXEC_COMMAND_LINE_SIZE 256
+#define KEXEC_ARGV_SIZE (KEXEC_COMMAND_LINE_SIZE / 16)
+#define KEXEC_MAX_ARGC (KEXEC_ARGV_SIZE / sizeof(long))
+
+#endif
--- a/arch/mips/kernel/relocate_kernel.S
+++ b/arch/mips/kernel/relocate_kernel.S
@@ -10,10 +10,11 @@
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/addrspace.h>
+#include "machine_kexec.h"
#include <kernel-entry-init.h>
-LEAF(relocate_new_kernel)
+LEAF(kexec_relocate_new_kernel)
PTR_L a0, arg0
PTR_L a1, arg1
PTR_L a2, arg2
@@ -98,7 +99,7 @@ done:
#endif
/* jump to kexec_start_address */
j s1
- END(relocate_new_kernel)
+ END(kexec_relocate_new_kernel)
#ifdef CONFIG_SMP
/*
@@ -177,8 +178,15 @@ EXPORT(kexec_indirection_page)
PTR_WD 0
.size kexec_indirection_page, PTRSIZE
-relocate_new_kernel_end:
+kexec_argv_buf:
+ EXPORT(kexec_argv_buf)
+ .skip KEXEC_COMMAND_LINE_SIZE
+ .size kexec_argv_buf, KEXEC_COMMAND_LINE_SIZE
+
+kexec_argv:
+ EXPORT(kexec_argv)
+ .skip KEXEC_ARGV_SIZE
+ .size kexec_argv, KEXEC_ARGV_SIZE
-EXPORT(relocate_new_kernel_size)
- PTR_WD relocate_new_kernel_end - relocate_new_kernel
- .size relocate_new_kernel_size, PTRSIZE
+kexec_relocate_new_kernel_end:
+ EXPORT(kexec_relocate_new_kernel_end)