Newer s390 kernels support a command line size longer than 896
bytes. Such kernels contain a new member in the parameter area,
which might be utilized by tools like kexec. Older kernels have
the location initialized to zero, so we check whether there's a
non-zero number present and use that. If there isn't, we fallback
to the legacy command line size of 896 bytes.
Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Reviewed-by: Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
---
kexec/arch/s390/kexec-image.c | 53 ++++++++++++++++++++++++-----------
kexec/arch/s390/kexec-s390.h | 19 +++++++------
2 files changed, 46 insertions(+), 26 deletions(-)
diff --git a/kexec/arch/s390/kexec-image.c b/kexec/arch/s390/kexec-image.c
index 3c24fdfe3c7c..7747d02399db 100644
--- a/kexec/arch/s390/kexec-image.c
+++ b/kexec/arch/s390/kexec-image.c
@@ -25,7 +25,7 @@
#include <fcntl.h>
static uint64_t crash_base, crash_end;
-static char command_line[COMMAND_LINESIZE];
+static char *command_line;
static void add_segment_check(struct kexec_info *info, const void *buf,
size_t bufsz, unsigned long base, size_t memsz)
@@ -38,11 +38,16 @@ static void add_segment_check(struct kexec_info *info, const void *buf,
int command_line_add(const char *str)
{
- if (strlen(command_line) + strlen(str) + 1 > COMMAND_LINESIZE) {
- fprintf(stderr, "Command line too long.\n");
+ char *tmp = NULL;
+
+ tmp = concat_cmdline(command_line, str);
+ if (!tmp) {
+ fprintf(stderr, "out of memory\n");
return -1;
}
- strcat(command_line, str);
+
+ free(command_line);
+ command_line = tmp;
return 0;
}
@@ -78,6 +83,8 @@ int image_s390_load_file(int argc, char **argv, struct kexec_info *info)
if (info->initrd_fd == -1) {
fprintf(stderr, "Could not open initrd file %s:%s\n",
ramdisk, strerror(errno));
+ free(command_line);
+ command_line = NULL;
return -1;
}
}
@@ -97,7 +104,7 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
const char *ramdisk;
off_t ramdisk_len;
unsigned int ramdisk_origin;
- int opt;
+ int opt, ret = -1;
if (info->file_mode)
return image_s390_load_file(argc, argv, info);
@@ -112,7 +119,6 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
};
static const char short_options[] = KEXEC_OPT_STR "";
- command_line[0] = 0;
ramdisk = NULL;
ramdisk_len = 0;
ramdisk_origin = 0;
@@ -132,7 +138,7 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
if (info->kexec_flags & KEXEC_ON_CRASH) {
if (parse_iomem_single("Crash kernel\n", &crash_base,
&crash_end))
- return -1;
+ goto out;
}
/* Add kernel segment */
@@ -151,7 +157,7 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
rd_buffer = slurp_file_mmap(ramdisk, &ramdisk_len);
if (rd_buffer == NULL) {
fprintf(stderr, "Could not read ramdisk.\n");
- return -1;
+ goto out;
}
ramdisk_origin = MAX(RAMDISK_ORIGIN_ADDR, kernel_size);
ramdisk_origin = _ALIGN_UP(ramdisk_origin, 0x100000);
@@ -160,7 +166,7 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
}
if (info->kexec_flags & KEXEC_ON_CRASH) {
if (load_crashdump_segments(info, crash_base, crash_end))
- return -1;
+ goto out;
} else {
info->entry = (void *) IMAGE_READ_OFFSET;
}
@@ -183,15 +189,28 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
*tmp = crash_end - crash_base + 1;
}
}
- /*
- * We will write a probably given command line.
- * First, erase the old area, then setup the new parameters:
- */
- if (strlen(command_line) != 0) {
- memset(krnl_buffer + COMMAND_LINE_OFFS, 0, COMMAND_LINESIZE);
- memcpy(krnl_buffer + COMMAND_LINE_OFFS, command_line, strlen(command_line));
+
+ if (command_line) {
+ unsigned long maxsize;
+ char *dest = krnl_buffer + COMMAND_LINE_OFFS;
+
+ maxsize = *(unsigned long *)(krnl_buffer + MAX_COMMAND_LINESIZE_OFFS);
+ if (!maxsize)
+ maxsize = LEGACY_COMMAND_LINESIZE;
+
+ if (strlen(command_line) > maxsize-1) {
+ fprintf(stderr, "command line too long, maximum allowed size %ld\n",
+ maxsize-1);
+ goto out;
+ }
+ strncpy(dest, command_line, maxsize-1);
+ dest[maxsize-1] = '\0';
}
- return 0;
+ ret = 0;
+out:
+ free(command_line);
+ command_line = NULL;
+ return ret;
}
int
diff --git a/kexec/arch/s390/kexec-s390.h b/kexec/arch/s390/kexec-s390.h
index ef53b111e167..1b0e04848460 100644
--- a/kexec/arch/s390/kexec-s390.h
+++ b/kexec/arch/s390/kexec-s390.h
@@ -10,16 +10,17 @@
#ifndef KEXEC_S390_H
#define KEXEC_S390_H
-#define IMAGE_READ_OFFSET 0x10000
+#define IMAGE_READ_OFFSET 0x10000
-#define RAMDISK_ORIGIN_ADDR 0x800000
-#define INITRD_START_OFFS 0x408
-#define INITRD_SIZE_OFFS 0x410
-#define OLDMEM_BASE_OFFS 0x418
-#define OLDMEM_SIZE_OFFS 0x420
-#define COMMAND_LINE_OFFS 0x480
-#define COMMAND_LINESIZE 896
-#define MAX_MEMORY_RANGES 1024
+#define RAMDISK_ORIGIN_ADDR 0x800000
+#define INITRD_START_OFFS 0x408
+#define INITRD_SIZE_OFFS 0x410
+#define OLDMEM_BASE_OFFS 0x418
+#define OLDMEM_SIZE_OFFS 0x420
+#define MAX_COMMAND_LINESIZE_OFFS 0x430
+#define COMMAND_LINE_OFFS 0x480
+#define LEGACY_COMMAND_LINESIZE 896
+#define MAX_MEMORY_RANGES 1024
#define MAX(x, y) ((x) > (y) ? (x) : (y))
#define MIN(x, y) ((x) < (y) ? (x) : (y))
--
2.25.1
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