From e63fefd4fc355f29d839ca47484b0f8070e38ccb Mon Sep 17 00:00:00 2001

From: Sourabh Jain <sourabhjain@linux.ibm.com>

Date: Wed, 1 Feb 2023 14:23:31 +0530

Subject: [PATCH 1/6] ppc64: add --reuse-cmdline parameter support

An option to copy the command line arguments from running kernel

to kexec'd kernel. This option works for both kexec and kdump.

In case --append=<args> or --command-line=<args> is provided along

with --reuse-cmdline parameter then args listed against append and

command-line parameter will be combined with command line argument

from running kernel.

Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>

Signed-off-by: Simon Horman <horms@kernel.org>

---

 kexec/arch/ppc64/include/arch/options.h |  4 +++-

 kexec/arch/ppc64/kexec-elf-ppc64.c      | 25 +++++++++++++++++++++++--

 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/kexec/arch/ppc64/include/arch/options.h b/kexec/arch/ppc64/include/arch/options.h

index 71632ec..2bca96a 100644

--- a/kexec/arch/ppc64/include/arch/options.h

+++ b/kexec/arch/ppc64/include/arch/options.h

@@ -10,6 +10,7 @@

 #define OPT_RAMDISK		(OPT_ARCH_MAX+1)

 #define OPT_DEVICETREEBLOB	(OPT_ARCH_MAX+2)

 #define OPT_ARGS_IGNORE		(OPT_ARCH_MAX+3)

+#define OPT_REUSE_CMDLINE	(OPT_ARCH_MAX+4)

 /* Options relevant to the architecture (excluding loader-specific ones): */

 #define KEXEC_ARCH_OPTIONS \

@@ -41,7 +42,8 @@

 	{ "initrd",             1, NULL, OPT_RAMDISK },		\

 	{ "devicetreeblob",     1, NULL, OPT_DEVICETREEBLOB },	\

 	{ "dtb",                1, NULL, OPT_DEVICETREEBLOB },	\

-	{ "args-linux",         0, NULL, OPT_ARGS_IGNORE },

+	{ "args-linux",         0, NULL, OPT_ARGS_IGNORE },	\

+	{ "reuse-cmdline",      0, NULL, OPT_REUSE_CMDLINE },

 #define KEXEC_ALL_OPT_STR KEXEC_OPT_STR

diff --git a/kexec/arch/ppc64/kexec-elf-ppc64.c b/kexec/arch/ppc64/kexec-elf-ppc64.c

index 695b8b0..01d045f 100644

--- a/kexec/arch/ppc64/kexec-elf-ppc64.c

+++ b/kexec/arch/ppc64/kexec-elf-ppc64.c

@@ -95,6 +95,8 @@ static int elf_ppc64_load_file(int argc, char **argv, struct kexec_info *info)

 {

 	int ret = 0;

 	char *cmdline, *dtb;

+	char *append_cmdline = NULL;

+	char *reuse_cmdline = NULL;

 	int opt, cmdline_len = 0;

 	/* See options.h -- add any more there, too. */

@@ -107,6 +109,7 @@ static int elf_ppc64_load_file(int argc, char **argv, struct kexec_info *info)

 		{ "devicetreeblob",     1, NULL, OPT_DEVICETREEBLOB },

 		{ "dtb",                1, NULL, OPT_DEVICETREEBLOB },

 		{ "args-linux",		0, NULL, OPT_ARGS_IGNORE },

+		{ "reuse-cmdline",	0, NULL, OPT_REUSE_CMDLINE},

 		{ 0,                    0, NULL, 0 },

 	};

@@ -125,7 +128,7 @@ static int elf_ppc64_load_file(int argc, char **argv, struct kexec_info *info)

 			if (opt < OPT_ARCH_MAX)

 				break;

 		case OPT_APPEND:

-			cmdline = optarg;

+			append_cmdline = optarg;

 			break;

 		case OPT_RAMDISK:

 			ramdisk = optarg;

@@ -135,6 +138,9 @@ static int elf_ppc64_load_file(int argc, char **argv, struct kexec_info *info)

 			break;

 		case OPT_ARGS_IGNORE:

 			break;

+		case OPT_REUSE_CMDLINE:

+			reuse_cmdline = get_command_line();

+			break;

 		}

 	}

@@ -144,6 +150,10 @@ static int elf_ppc64_load_file(int argc, char **argv, struct kexec_info *info)

 	if (reuse_initrd)

 		die("--reuseinitrd not supported with --kexec-file-syscall.\n");

+	cmdline = concat_cmdline(reuse_cmdline, append_cmdline);

+	if (!reuse_cmdline)

+		free(reuse_cmdline);

+

 	if (cmdline) {

 		cmdline_len = strlen(cmdline) + 1;

 	} else {

@@ -175,6 +185,8 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,

 {

 	struct mem_ehdr ehdr;

 	char *cmdline, *modified_cmdline = NULL;

+	char *reuse_cmdline = NULL;

+	char *append_cmdline = NULL;

 	const char *devicetreeblob;

 	uint64_t max_addr, hole_addr;

 	char *seg_buf = NULL;

@@ -204,6 +216,7 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,

 		{ "devicetreeblob",     1, NULL, OPT_DEVICETREEBLOB },

 		{ "dtb",                1, NULL, OPT_DEVICETREEBLOB },

 		{ "args-linux",		0, NULL, OPT_ARGS_IGNORE },

+		{ "reuse-cmdline",	0, NULL, OPT_REUSE_CMDLINE},

 		{ 0,                    0, NULL, 0 },

 	};

@@ -229,7 +242,7 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,

 			if (opt < OPT_ARCH_MAX)

 				break;

 		case OPT_APPEND:

-			cmdline = optarg;

+			append_cmdline = optarg;

 			break;

 		case OPT_RAMDISK:

 			ramdisk = optarg;

@@ -239,9 +252,16 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,

 			break;

 		case OPT_ARGS_IGNORE:

 			break;

+		case OPT_REUSE_CMDLINE:

+			reuse_cmdline = get_command_line();

+			break;

 		}

 	}

+	cmdline = concat_cmdline(reuse_cmdline, append_cmdline);

+	if (!reuse_cmdline)

+		free(reuse_cmdline);

+

 	if (!cmdline)

 		fprintf(stdout, "Warning: append= option is not passed. Using the first kernel root partition\n");

@@ -469,6 +489,7 @@ void elf_ppc64_usage(void)

 	fprintf(stderr, "     --devicetreeblob=<filename> Specify device tree blob file.\n");

 	fprintf(stderr, "                                 ");

 	fprintf(stderr, "Not applicable while using --kexec-file-syscall.\n");

+	fprintf(stderr, "     --reuse-cmdline Use kernel command line from running system.\n");

 	fprintf(stderr, "     --dtb=<filename> same as --devicetreeblob.\n");

 	fprintf(stderr, "elf support is still broken\n");

-- 

2.33.1