On Thu, Jun 26, 2014 at 04:33:29PM -0400, Vivek Goyal wrote: > Hi, > > This is V4 of the patchset. Previous versions were posted here. > > V1: https://lkml.org/lkml/2013/11/20/540 > V2: https://lkml.org/lkml/2014/1/27/331 > V3: https://lkml.org/lkml/2014/6/3/432 > I used following kexec-tools patch to test my changes. Thanks Vivek kexec-tools: Provide an option to make use of new system call This patch provides and option --kexec-file-syscall, to force use of new system call for kexec. Default is to continue to use old syscall. Signed-off-by: Vivek Goyal <vgoyal at redhat.com> --- kexec/arch/x86_64/kexec-bzImage64.c | 86 +++++++++++++++++++++++ kexec/kexec-syscall.h | 32 ++++++++ kexec/kexec.c | 132 +++++++++++++++++++++++++++++++++++- kexec/kexec.h | 11 ++- 4 files changed, 257 insertions(+), 4 deletions(-) Index: kexec-tools/kexec/kexec.c =================================================================== --- kexec-tools.orig/kexec/kexec.c 2014-06-17 13:15:37.723825990 -0400 +++ kexec-tools/kexec/kexec.c 2014-06-26 15:19:59.064940065 -0400 @@ -51,6 +51,8 @@ unsigned long long mem_min = 0; unsigned long long mem_max = ULONG_MAX; static unsigned long kexec_flags = 0; +/* Flags for kexec file (fd) based syscall */ +static unsigned long kexec_file_flags = 0; int kexec_debug = 0; void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr) @@ -787,6 +789,19 @@ static int my_load(const char *type, int return result; } +static int kexec_file_unload(unsigned long kexec_file_flags) +{ + int ret = 0; + + ret = kexec_file_load(-1, -1, 0, NULL, kexec_file_flags); + if (ret != 0) { + /* The unload failed, print some debugging information */ + fprintf(stderr, "kexec_file_load(unload) failed\n: %s\n", + strerror(errno)); + } + return ret; +} + static int k_unload (unsigned long kexec_flags) { int result; @@ -925,6 +940,7 @@ void usage(void) " (0 means it's not jump back or\n" " preserve context)\n" " to original kernel.\n" + " -s --kexec-file-syscall Use file based syscall for kexec operation\n" " -d, --debug Enable debugging to help spot a failure.\n" "\n" "Supported kernel file types and options: \n"); @@ -1072,6 +1088,82 @@ char *concat_cmdline(const char *base, c return cmdline; } +/* New file based kexec system call related code */ +static int do_kexec_file_load(int fileind, int argc, char **argv, + unsigned long flags) { + + char *kernel; + int kernel_fd, i; + struct kexec_info info; + int ret = 0; + char *kernel_buf; + off_t kernel_size; + + memset(&info, 0, sizeof(info)); + info.segment = NULL; + info.nr_segments = 0; + info.entry = NULL; + info.backup_start = 0; + info.kexec_flags = flags; + + info.file_mode = 1; + info.initrd_fd = -1; + + if (argc - fileind <= 0) { + fprintf(stderr, "No kernel specified\n"); + usage(); + return -1; + } + + kernel = argv[fileind]; + + kernel_fd = open(kernel, O_RDONLY); + if (kernel_fd == -1) { + fprintf(stderr, "Failed to open file %s:%s\n", kernel, + strerror(errno)); + return -1; + } + + /* slurp in the input kernel */ + kernel_buf = slurp_decompress_file(kernel, &kernel_size); + + for (i = 0; i < file_types; i++) { + if (file_type[i].probe(kernel_buf, kernel_size) >= 0) + break; + } + + if (i == file_types) { + fprintf(stderr, "Cannot determine the file type " "of %s\n", + kernel); + return -1; + } + + ret = file_type[i].load(argc, argv, kernel_buf, kernel_size, &info); + if (ret < 0) { + fprintf(stderr, "Cannot load %s\n", kernel); + return ret; + } + + if (!is_kexec_file_load_implemented()) { + fprintf(stderr, "syscall kexec_file_load not available.\n"); + return -1; + } + + /* + * If there is no initramfs, set KEXEC_FILE_NO_INITRAMFS flag so that + * kernel does not return error with negative initrd_fd. + */ + if (info.initrd_fd == -1) + info.kexec_flags |= KEXEC_FILE_NO_INITRAMFS; + + ret = kexec_file_load(kernel_fd, info.initrd_fd, info.command_line_len, + info.command_line, info.kexec_flags); + if (ret != 0) + fprintf(stderr, "kexec_file_load failed: %s\n", + strerror(errno)); + return ret; +} + int main(int argc, char *argv[]) { @@ -1083,6 +1175,7 @@ int main(int argc, char *argv[]) int do_ifdown = 0; int do_unload = 0; int do_reuse_initrd = 0; + int do_kexec_file_syscall = 0; void *entry = 0; char *type = 0; char *endptr; @@ -1095,6 +1188,23 @@ int main(int argc, char *argv[]) }; static const char short_options[] = KEXEC_ALL_OPT_STR; + /* + * First check if --use-kexec-file-syscall is set. That changes lot of + * things + */ + while ((opt = getopt_long(argc, argv, short_options, + options, 0)) != -1) { + switch(opt) { + case OPT_KEXEC_FILE_SYSCALL: + do_kexec_file_syscall = 1; + break; + } + } + + /* Reset getopt for the next pass. */ + opterr = 1; + optind = 1; + while ((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) { switch(opt) { @@ -1127,6 +1237,8 @@ int main(int argc, char *argv[]) do_shutdown = 0; do_sync = 0; do_unload = 1; + if (do_kexec_file_syscall) + kexec_file_flags |= KEXEC_FILE_UNLOAD; break; case OPT_EXEC: do_load = 0; @@ -1169,7 +1281,10 @@ int main(int argc, char *argv[]) do_exec = 0; do_shutdown = 0; do_sync = 0; - kexec_flags = KEXEC_ON_CRASH; + if (do_kexec_file_syscall) + kexec_file_flags |= KEXEC_FILE_ON_CRASH; + else + kexec_flags = KEXEC_ON_CRASH; break; case OPT_MEM_MIN: mem_min = strtoul(optarg, &endptr, 0); @@ -1194,6 +1309,9 @@ int main(int argc, char *argv[]) case OPT_REUSE_INITRD: do_reuse_initrd = 1; break; + case OPT_KEXEC_FILE_SYSCALL: + /* We already parsed it. Nothing to do. */ + break; default: break; } @@ -1238,10 +1356,18 @@ int main(int argc, char *argv[]) } if (do_unload) { - result = k_unload(kexec_flags); + if (do_kexec_file_syscall) + result = kexec_file_unload(kexec_file_flags); + else + result = k_unload(kexec_flags); } if (do_load && (result == 0)) { - result = my_load(type, fileind, argc, argv, kexec_flags, entry); + if (do_kexec_file_syscall) + result = do_kexec_file_load(fileind, argc, argv, + kexec_file_flags); + else + result = my_load(type, fileind, argc, argv, + kexec_flags, entry); } /* Don't shutdown unless there is something to reboot to! */ if ((result == 0) && (do_shutdown || do_exec) && !kexec_loaded()) { Index: kexec-tools/kexec/kexec.h =================================================================== --- kexec-tools.orig/kexec/kexec.h 2014-06-17 13:15:37.723825990 -0400 +++ kexec-tools/kexec/kexec.h 2014-06-17 13:44:14.634927130 -0400 @@ -156,6 +156,13 @@ struct kexec_info { unsigned long kexec_flags; unsigned long backup_src_start; unsigned long backup_src_size; + /* Set to 1 if we are using kexec file syscall */ + unsigned long file_mode :1; + + /* Filled by kernel image processing code */ + int initrd_fd; + char *command_line; + int command_line_len; }; struct arch_map_entry { @@ -207,6 +214,7 @@ extern int file_types; #define OPT_UNLOAD 'u' #define OPT_TYPE 't' #define OPT_PANIC 'p' +#define OPT_KEXEC_FILE_SYSCALL 's' #define OPT_MEM_MIN 256 #define OPT_MEM_MAX 257 #define OPT_REUSE_INITRD 258 @@ -230,9 +238,10 @@ extern int file_types; { "mem-min", 1, 0, OPT_MEM_MIN }, \ { "mem-max", 1, 0, OPT_MEM_MAX }, \ { "reuseinitrd", 0, 0, OPT_REUSE_INITRD }, \ + { "kexec-file-syscall", 0, 0, OPT_KEXEC_FILE_SYSCALL }, \ { "debug", 0, 0, OPT_DEBUG }, \ -#define KEXEC_OPT_STR "h?vdfxluet:p" +#define KEXEC_OPT_STR "h?vdfxluet:ps" extern void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr); extern void die(const char *fmt, ...) Index: kexec-tools/kexec/arch/x86_64/kexec-bzImage64.c =================================================================== --- kexec-tools.orig/kexec/arch/x86_64/kexec-bzImage64.c 2014-06-17 13:15:37.723825990 -0400 +++ kexec-tools/kexec/arch/x86_64/kexec-bzImage64.c 2014-06-17 13:17:39.916833188 -0400 @@ -235,6 +235,89 @@ static int do_bzImage64_load(struct kexe return 0; } +/* This assumes file is being loaded using file based kexec2 syscall */ +int bzImage64_load_file(int argc, char **argv, struct kexec_info *info) +{ + int ret = 0; + char *command_line = NULL, *tmp_cmdline = NULL; + const char *ramdisk = NULL, *append = NULL; + int entry_16bit = 0, entry_32bit = 0; + int opt; + int command_line_len; + + /* See options.h -- add any more there, too. */ + static const struct option options[] = { + KEXEC_ARCH_OPTIONS + { "command-line", 1, 0, OPT_APPEND }, + { "append", 1, 0, OPT_APPEND }, + { "reuse-cmdline", 0, 0, OPT_REUSE_CMDLINE }, + { "initrd", 1, 0, OPT_RAMDISK }, + { "ramdisk", 1, 0, OPT_RAMDISK }, + { "real-mode", 0, 0, OPT_REAL_MODE }, + { "entry-32bit", 0, 0, OPT_ENTRY_32BIT }, + { 0, 0, 0, 0 }, + }; + static const char short_options[] = KEXEC_ARCH_OPT_STR "d"; + + while ((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) { + switch (opt) { + default: + /* Ignore core options */ + if (opt < OPT_ARCH_MAX) + break; + case OPT_APPEND: + append = optarg; + break; + case OPT_REUSE_CMDLINE: + tmp_cmdline = get_command_line(); + break; + case OPT_RAMDISK: + ramdisk = optarg; + break; + case OPT_REAL_MODE: + entry_16bit = 1; + break; + case OPT_ENTRY_32BIT: + entry_32bit = 1; + break; + } + } + command_line = concat_cmdline(tmp_cmdline, append); + if (tmp_cmdline) + free(tmp_cmdline); + command_line_len = 0; + if (command_line) { + command_line_len = strlen(command_line) + 1; + } else { + command_line = strdup("\0"); + command_line_len = 1; + } + + if (entry_16bit || entry_32bit) { + fprintf(stderr, "Kexec2 syscall does not support 16bit" + " or 32bit entry yet\n"); + ret = -1; + goto out; + } + + if (ramdisk) { + info->initrd_fd = open(ramdisk, O_RDONLY); + if (info->initrd_fd == -1) { + fprintf(stderr, "Could not open initrd file %s:%s\n", + ramdisk, strerror(errno)); + ret = -1; + goto out; + } + } + + info->command_line = command_line; + info->command_line_len = command_line_len; + return ret; +out: + free(command_line); + return ret; +} + int bzImage64_load(int argc, char **argv, const char *buf, off_t len, struct kexec_info *info) { @@ -247,6 +330,9 @@ int bzImage64_load(int argc, char **argv int opt; int result; + if (info->file_mode) + return bzImage64_load_file(argc, argv, info); + /* See options.h -- add any more there, too. */ static const struct option options[] = { KEXEC_ARCH_OPTIONS Index: kexec-tools/kexec/kexec-syscall.h =================================================================== --- kexec-tools.orig/kexec/kexec-syscall.h 2014-06-17 13:15:37.723825990 -0400 +++ kexec-tools/kexec/kexec-syscall.h 2014-06-26 15:19:59.063940065 -0400 @@ -53,6 +53,19 @@ #endif #endif /*ifndef __NR_kexec_load*/ +#ifndef __NR_kexec_file_load + +#ifdef __x86_64__ +#define __NR_kexec_file_load 317 +#endif + +#ifndef __NR_kexec_file_load +/* system call not available for the arch */ +#define __NR_kexec_file_load 0xffffffff /* system call not available */ +#endif + +#endif /*ifndef __NR_kexec_file_load*/ + struct kexec_segment; static inline long kexec_load(void *entry, unsigned long nr_segments, @@ -61,10 +74,29 @@ static inline long kexec_load(void *entr return (long) syscall(__NR_kexec_load, entry, nr_segments, segments, flags); } +static inline int is_kexec_file_load_implemented(void) { + if (__NR_kexec_file_load != 0xffffffff) + return 1; + return 0; +} + +static inline long kexec_file_load(int kernel_fd, int initrd_fd, + unsigned long cmdline_len, const char *cmdline_ptr, + unsigned long flags) +{ + return (long) syscall(__NR_kexec_file_load, kernel_fd, initrd_fd, + cmdline_len, cmdline_ptr, flags); +} + #define KEXEC_ON_CRASH 0x00000001 #define KEXEC_PRESERVE_CONTEXT 0x00000002 #define KEXEC_ARCH_MASK 0xffff0000 +/* Flags for kexec file based system call */ +#define KEXEC_FILE_UNLOAD 0x00000001 +#define KEXEC_FILE_ON_CRASH 0x00000002 +#define KEXEC_FILE_NO_INITRAMFS 0x00000004 + /* These values match the ELF architecture values. * Unless there is a good reason that should continue to be the case. */
