[PATCH v3 1/5] s390: add variable command line size
Sven Schnelle
svens at linux.ibm.com
Thu Dec 16 03:43:52 PST 2021
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 at linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar at linux.ibm.com>
---
kexec/arch/s390/crashdump-s390.c | 3 +-
kexec/arch/s390/kexec-image.c | 65 +++++++++++++++++++++-----------
kexec/arch/s390/kexec-s390.h | 21 ++++++-----
3 files changed, 55 insertions(+), 34 deletions(-)
diff --git a/kexec/arch/s390/crashdump-s390.c b/kexec/arch/s390/crashdump-s390.c
index 10f4d607bbcc..3bd9efe6dafe 100644
--- a/kexec/arch/s390/crashdump-s390.c
+++ b/kexec/arch/s390/crashdump-s390.c
@@ -52,7 +52,8 @@ static int create_elf_header(struct kexec_info *info, unsigned long crash_base,
elfcorehdr_size = bufsz;
snprintf(str, sizeof(str), " elfcorehdr=%ld@%ldK\n",
elfcorehdr_size, elfcorehdr / 1024);
- command_line_add(str);
+ if (command_line_add(info, str))
+ return -1;
#endif
return 0;
}
diff --git a/kexec/arch/s390/kexec-image.c b/kexec/arch/s390/kexec-image.c
index 3c24fdfe3c7c..a52399eafd2a 100644
--- a/kexec/arch/s390/kexec-image.c
+++ b/kexec/arch/s390/kexec-image.c
@@ -25,7 +25,6 @@
#include <fcntl.h>
static uint64_t crash_base, crash_end;
-static char command_line[COMMAND_LINESIZE];
static void add_segment_check(struct kexec_info *info, const void *buf,
size_t bufsz, unsigned long base, size_t memsz)
@@ -36,13 +35,18 @@ static void add_segment_check(struct kexec_info *info, const void *buf,
add_segment(info, buf, bufsz, crash_base + base, memsz);
}
-int command_line_add(const char *str)
+int command_line_add(struct kexec_info *info, 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(info->command_line, str);
+ if (!tmp) {
+ fprintf(stderr, "out of memory\n");
return -1;
}
- strcat(command_line, str);
+
+ free(info->command_line);
+ info->command_line = tmp;
return 0;
}
@@ -64,7 +68,7 @@ int image_s390_load_file(int argc, char **argv, struct kexec_info *info)
while ((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) {
switch(opt) {
case OPT_APPEND:
- if (command_line_add(optarg))
+ if (command_line_add(info, optarg))
return -1;
break;
case OPT_RAMDISK:
@@ -78,13 +82,16 @@ 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(info->command_line);
+ info->command_line = NULL;
return -1;
}
}
- info->command_line = command_line;
- info->command_line_len = strlen (command_line) + 1;
-
+ if (info->command_line)
+ info->command_line_len = strlen(info->command_line) + 1;
+ else
+ info->command_line_len = 0;
return 0;
}
@@ -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;
@@ -120,7 +126,7 @@ image_s390_load(int argc, char **argv, const char *kernel_buf,
while ((opt = getopt_long(argc,argv,short_options,options,0)) != -1) {
switch(opt) {
case OPT_APPEND:
- if (command_line_add(optarg))
+ if (command_line_add(info, optarg))
return -1;
break;
case OPT_RAMDISK:
@@ -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 (info->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(info->command_line) > maxsize-1) {
+ fprintf(stderr, "command line too long, maximum allowed size %ld\n",
+ maxsize-1);
+ goto out;
+ }
+ strncpy(dest, info->command_line, maxsize-1);
+ dest[maxsize-1] = '\0';
}
- return 0;
+ ret = 0;
+out:
+ free(info->command_line);
+ info->command_line = NULL;
+ return ret;
}
int
diff --git a/kexec/arch/s390/kexec-s390.h b/kexec/arch/s390/kexec-s390.h
index ef53b111e167..6a99518c1c9e 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))
@@ -32,6 +33,6 @@ extern int load_crashdump_segments(struct kexec_info *info,
unsigned long crash_end);
extern int get_memory_ranges_s390(struct memory_range range[], int *ranges,
int with_crashk);
-extern int command_line_add(const char *str);
+extern int command_line_add(struct kexec_info *info, const char *str);
#endif /* KEXEC_S390_H */
--
2.32.0
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