From: Michael Neuling <mikey@neuling.org>
To: Bernhard Walle <bwalle@suse.de>
Cc: kexec@lists.infradead.org
Subject: Re: [PATCH] Add --reuse-cmdline
Date: Fri, 09 May 2008 12:13:25 -0500 [thread overview]
Message-ID: <19164.1210353205@neuling.org> (raw)
In-Reply-To: <20080508204943.GA24160@suse.de>
In message <20080508204943.GA24160@suse.de> you wrote:
> This patch adds an option "--reuse-cmdline" for people that are lazy in typin
g
> --append="$(cat /proc/cmdline)". The advantage of "--reuse-cmdline" is also t
hat
> it strips off BOOT_IMAGE (since it may not be correct any more) from lilo and
> other boot loaders, and, more important, the crashkernel option in case a
> panic kernel is loaded.
>
> If you like the option I can also add it for really all architectures. Tested
only
> with x86-bzImage both the kexec and kdump case.
For ppc64, the default is to reuse the command line. We should probably
merge functionality.
Either way, this should probably be a generic option, not x86 specific.
Mikey
>
>
> Signed-off-by: Bernhard Walle <bwalle@suse.de>
>
> ---
> kexec/arch/i386/kexec-bzImage.c | 12 +++-
> kexec/arch/i386/kexec-elf-x86.c | 16 ++++--
> kexec/arch/i386/kexec-multiboot-x86.c | 12 +++-
> kexec/arch/x86_64/kexec-elf-x86_64.c | 16 ++++--
> kexec/kexec.8 | 18 +++++++
> kexec/kexec.c | 85 +++++++++++++++++++++++++++++--
---
> kexec/kexec.h | 1
> 7 files changed, 132 insertions(+), 28 deletions(-)
>
> --- a/kexec/arch/i386/kexec-bzImage.c
> +++ b/kexec/arch/i386/kexec-bzImage.c
> @@ -89,6 +89,7 @@ void bzImage_usage(void)
> " --real-mode Use the kernels real mode entry poin
t.\n"
> " --command-line=STRING Set the kernel command line to STRIN
G.\n"
> " --append=STRING Set the kernel command line to STRIN
G.\n"
> + " --reuse-cmdline Use kernel command line from running
system.\n"
> " --initrd=FILE Use FILE as the kernel's initial ram
disk.\n"
> " --ramdisk=FILE Use FILE as the kernel's initial ram
disk.\n"
> );
> @@ -335,14 +336,16 @@ int bzImage_load(int argc, char **argv,
> int debug, real_mode_entry;
> int opt;
> int result;
> -#define OPT_APPEND (OPT_ARCH_MAX+0)
> -#define OPT_RAMDISK (OPT_ARCH_MAX+1)
> -#define OPT_REAL_MODE (OPT_ARCH_MAX+2)
> +#define OPT_APPEND (OPT_ARCH_MAX+0)
> +#define OPT_REUSE_CMDLINE (OPT_ARCH_MAX+1)
> +#define OPT_RAMDISK (OPT_ARCH_MAX+2)
> +#define OPT_REAL_MODE (OPT_ARCH_MAX+3)
What space updates?
> static const struct option options[] = {
> KEXEC_ARCH_OPTIONS
> { "debug", 0, 0, OPT_DEBUG },
> { "command-line", 1, 0, OPT_APPEND },
> { "append", 1, 0, OPT_APPEND },
> + { "reuse-cmdline", 1, 0, OPT_REUSE_CMDLINE },
> { "initrd", 1, 0, OPT_RAMDISK },
> { "ramdisk", 1, 0, OPT_RAMDISK },
> { "real-mode", 0, 0, OPT_REAL_MODE },
> @@ -374,6 +377,9 @@ int bzImage_load(int argc, char **argv,
> case OPT_APPEND:
> command_line = optarg;
> break;
> + case OPT_REUSE_CMDLINE:
> + command_line = get_command_line();
> + break;
> case OPT_RAMDISK:
> ramdisk = optarg;
> break;
> --- a/kexec/arch/i386/kexec-elf-x86.c
> +++ b/kexec/arch/i386/kexec-elf-x86.c
> @@ -73,6 +73,7 @@ void elf_x86_usage(void)
> {
> printf( " --command-line=STRING Set the kernel command line to STRIN
G\n"
> " --append=STRING Set the kernel command line to STRIN
G\n"
> + " --reuse-cmdline Use kernel command line from running
system.\n"
> " --initrd=FILE Use FILE as the kernel's initial ram
disk.\n"
> " --ramdisk=FILE Use FILE as the kernel's initial ram
disk.\n"
> " --args-linux Pass linux kernel style options\n"
> @@ -97,16 +98,18 @@ int elf_x86_load(int argc, char **argv,
> #define ARG_STYLE_LINUX 1
> #define ARG_STYLE_NONE 2
> int opt;
> -#define OPT_APPEND (OPT_ARCH_MAX+0)
> -#define OPT_RAMDISK (OPT_ARCH_MAX+1)
> -#define OPT_ARGS_ELF (OPT_ARCH_MAX+2)
> -#define OPT_ARGS_LINUX (OPT_ARCH_MAX+3)
> -#define OPT_ARGS_NONE (OPT_ARCH_MAX+4)
> +#define OPT_APPEND (OPT_ARCH_MAX+0)
> +#define OPT_REUSE_CMDLINE (OPT_ARCH_MAX+1)
> +#define OPT_RAMDISK (OPT_ARCH_MAX+2)
> +#define OPT_ARGS_ELF (OPT_ARCH_MAX+3)
> +#define OPT_ARGS_LINUX (OPT_ARCH_MAX+4)
> +#define OPT_ARGS_NONE (OPT_ARCH_MAX+5)
>
> static const struct option options[] = {
> KEXEC_ARCH_OPTIONS
> { "command-line", 1, NULL, OPT_APPEND },
> { "append", 1, NULL, OPT_APPEND },
> + { "reuse-cmdline", 1, NULL, OPT_REUSE_CMDLINE },
> { "initrd", 1, NULL, OPT_RAMDISK },
> { "ramdisk", 1, NULL, OPT_RAMDISK },
> { "args-elf", 0, NULL, OPT_ARGS_ELF },
> @@ -138,6 +141,9 @@ int elf_x86_load(int argc, char **argv,
> case OPT_APPEND:
> command_line = optarg;
> break;
> + case OPT_REUSE_CMDLINE:
> + command_line = get_command_line();
> + break;
> case OPT_RAMDISK:
> ramdisk = optarg;
> break;
> --- a/kexec/arch/i386/kexec-multiboot-x86.c
> +++ b/kexec/arch/i386/kexec-multiboot-x86.c
> @@ -129,6 +129,7 @@ void multiboot_x86_usage(void)
> /* Multiboot-specific options */
> {
> printf(" --command-line=STRING Set the kernel command line to
STRING.\n");
> + printf(" --reuse-cmdline Use kernel command line from r
unning system.\n");
> printf(" --module=\"MOD arg1 arg2...\" Load module MOD with command
-line \"arg1...\"\n");
> printf(" (can be used multiple times).\
n");
> }
> @@ -155,13 +156,15 @@ int multiboot_x86_load(int argc, char **
> int i;
> int opt;
> int modules, mod_command_line_space;
> -#define OPT_CL (OPT_ARCH_MAX+0)
> -#define OPT_MOD (OPT_ARCH_MAX+1)
> -#define OPT_VGA (OPT_ARCH_MAX+2)
> +#define OPT_CL (OPT_ARCH_MAX+0)
> +#define OPT_REUSE_CMDLINE (OPT_ARCH_MAX+1)
> +#define OPT_MOD (OPT_ARCH_MAX+2)
> +#define OPT_VGA (OPT_ARCH_MAX+3)
> static const struct option options[] = {
> KEXEC_ARCH_OPTIONS
> { "command-line", 1, 0, OPT_CL },
> { "append", 1, 0, OPT_CL },
> + { "reuse-cmdline", 1, 0, OPT_REUSE_CMDLINE },
> { "module", 1, 0, OPT_MOD },
> { 0, 0, 0, 0 },
> };
> @@ -194,6 +197,9 @@ int multiboot_x86_load(int argc, char **
> case OPT_CL:
> command_line = optarg;
> break;
> + case OPT_REUSE_CMDLINE:
> + command_line = get_command_line();
> + break;
> case OPT_MOD:
> modules++;
> mod_command_line_space += strlen(optarg) + 1;
> --- a/kexec/arch/x86_64/kexec-elf-x86_64.c
> +++ b/kexec/arch/x86_64/kexec-elf-x86_64.c
> @@ -73,6 +73,7 @@ void elf_x86_64_usage(void)
> {
> printf( " --command-line=STRING Set the kernel command line to STRIN
G\n"
> " --append=STRING Set the kernel command line to STRIN
G\n"
> + " --reuse-cmdline Use kernel command line from running
system.\n"
> " --initrd=FILE Use FILE as the kernel's initial ram
disk.\n"
> " --ramdisk=FILE Use FILE as the kernel's initial ram
disk.\n"
> " --args-linux Pass linux kernel style options\n"
> @@ -96,16 +97,18 @@ int elf_x86_64_load(int argc, char **arg
> #define ARG_STYLE_LINUX 1
> #define ARG_STYLE_NONE 2
> int opt;
> -#define OPT_APPEND (OPT_ARCH_MAX+0)
> -#define OPT_RAMDISK (OPT_ARCH_MAX+1)
> -#define OPT_ARGS_ELF (OPT_ARCH_MAX+2)
> -#define OPT_ARGS_LINUX (OPT_ARCH_MAX+3)
> -#define OPT_ARGS_NONE (OPT_ARCH_MAX+4)
> +#define OPT_APPEND (OPT_ARCH_MAX+0)
> +#define OPT_REUSE_CMDLINE (OPT_ARCH_MAX+1)
> +#define OPT_RAMDISK (OPT_ARCH_MAX+2)
> +#define OPT_ARGS_ELF (OPT_ARCH_MAX+3)
> +#define OPT_ARGS_LINUX (OPT_ARCH_MAX+4)
> +#define OPT_ARGS_NONE (OPT_ARCH_MAX+5)
>
> static const struct option options[] = {
> KEXEC_ARCH_OPTIONS
> { "command-line", 1, NULL, OPT_APPEND },
> { "append", 1, NULL, OPT_APPEND },
> + { "reuse-cmdline", 1, NULL, OPT_REUSE_CMDLINE },
> { "initrd", 1, NULL, OPT_RAMDISK },
> { "ramdisk", 1, NULL, OPT_RAMDISK },
> { "args-elf", 0, NULL, OPT_ARGS_ELF },
> @@ -138,6 +141,9 @@ int elf_x86_64_load(int argc, char **arg
> case OPT_APPEND:
> command_line = optarg;
> break;
> + case OPT_REUSE_CMDLINE:
> + command_line = get_command_line();
> + break;
> case OPT_RAMDISK:
> ramdisk = optarg;
> break;
> --- a/kexec/kexec.8
> +++ b/kexec/kexec.8
> @@ -186,6 +186,15 @@ to the kernel command line.
> Set the kernel command line to
> .IR string .
> .TP
> +.BI \-\-reuse-cmdline
> +Use the command line from the running system. When a panic kernel is loaded,
it
> +strips the
> +.I
> +crashkernel
> +parameter automatically. The
> +.I BOOT_IMAGE
> +parameter is also stripped.
> +.TP
> .BI \-\-initrd= file
> Use
> .I file
> @@ -204,6 +213,15 @@ as the kernel's initial ramdisk.
> Set the kernel command line to
> .IR string .
> .TP
> +.BI \-\-reuse-cmdline
> +Use the command line from the running system. When a panic kernel is loaded,
it
> +strips the
> +.I
> +crashkernel
> +parameter automatically. The
> +.I BOOT_IMAGE
> +parameter is also stripped.
> +.TP
> .BI \-\-module= "mod arg1 arg2 ..."
> Load module
> .I mod
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -31,6 +31,7 @@
> #include <unistd.h>
> #include <fcntl.h>
> #include <getopt.h>
> +#include <ctype.h>
>
> #include "config.h"
>
> @@ -46,6 +47,7 @@
>
> unsigned long long mem_min = 0;
> unsigned long long mem_max = ULONG_MAX;
> +unsigned long kexec_flags = 0;
>
> void die(char *fmt, ...)
> {
> @@ -792,26 +794,86 @@ static int kexec_loaded(void)
> return ret;
> }
>
> +/*
> + * Remove parameter from a kernel command line. Helper function by get_comma
nd_line().
> + */
> +static void remove_parameter(char *line, const char *param_name)
> +{
> + char *start, *end;
> +
> + start = strstr(line, param_name);
> +
> + /* parameter not found */
> + if (!start)
> + return;
> +
> + /*
> + * check if that's really the start of a parameter and not in
> + * the middle of the word
> + */
> + if (start != line && !isspace(*(start-1)))
> + return;
> +
> + end = strstr(start, " ");
> + if (!end)
> + *start = 0;
> + else {
> + memmove(start, end+1, strlen(end));
> + *(end + strlen(end)) = 0;
> + }
> +}
> +
> +/*
> + * Returns the contents of the current command line to be used with
> + * --reuse-cmdline option. The function gets called from architecture speci
fic
> + * code. If we load a panic kernel, that function will strip the
> + * "crashkernel=" option because it does not make sense that the crashkernel
> + * reserves memory for a crashkernel (well, it would not boot since the
> + * amount is exactly the same as the crashkernel has overall memory). Also,
> + * remove the BOOT_IMAGE from lilo (and others) since that doesn't make
> + * sense here any more. The kernel could be different even if we reuse the
> + * commandline.
> + *
> + * The function returns dynamically allocated memory.
> + */
> +char *get_command_line(void)
> +{
> + FILE *fp;
> + size_t len;
> + char *line = NULL;
> +
> + fp = fopen("/proc/cmdline", "r");
> + if (!fp)
> + die("Could not read /proc/cmdline.");
> + getline(&line, &len, fp);
> + fclose(fp);
> +
> + if (line) {
> + /* strip newline */
> + *(line + strlen(line) - 1) = 0;
> +
> + remove_parameter(line, "crashkernel");
> + if (kexec_flags & KEXEC_ON_CRASH)
> + remove_parameter(line, "BOOT_IMAGE");
> + } else
> + line = strdup("");
> +
> + return line;
> +}
> +
> /* check we retained the initrd */
> void check_reuse_initrd(void)
> {
> - FILE * fp;
> - char * line = NULL;
> - size_t len = 0;
> - ssize_t read;
> + char *line = get_command_line();
>
> - fp = fopen("/proc/cmdline", "r");
> - if (fp == NULL)
> - die("unable to open /proc/cmdline\n");
> - read = getline(&line, &len, fp);
> if (strstr(line, "retain_initrd") == NULL)
> die("unrecoverable error: current boot didn't "
> "retain the initrd for reuse.\n");
> - if (line)
> - free(line);
> - fclose(fp);
> +
> + free(line);
> }
>
> +
> int main(int argc, char *argv[])
> {
> int do_load = 1;
> @@ -821,7 +883,6 @@ int main(int argc, char *argv[])
> int do_ifdown = 0;
> int do_unload = 0;
> int do_reuse_initrd = 0;
> - unsigned long kexec_flags = 0;
> char *type = 0;
> char *endptr;
> int opt;
> --- a/kexec/kexec.h
> +++ b/kexec/kexec.h
> @@ -220,6 +220,7 @@ int arch_process_options(int argc, char
> int arch_compat_trampoline(struct kexec_info *info);
> void arch_update_purgatory(struct kexec_info *info);
> int is_crashkernel_mem_reserved(void);
> +char *get_command_line(void);
>
> int kexec_iomem_for_each_line(char *match,
> int (*callback)(void *data,
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>
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next prev parent reply other threads:[~2008-05-09 17:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-08 20:49 [PATCH] Add --reuse-cmdline Bernhard Walle
2008-05-08 22:02 ` Ben Woodard
2008-05-09 17:13 ` Michael Neuling [this message]
2008-05-12 13:38 ` Bernhard Walle
2008-05-12 19:43 ` Michael Neuling
2008-05-13 18:24 ` Lombard, David N
2008-05-21 11:30 ` Bernhard Walle
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