[Crash-utility] [PATCH v3 9/9] teach crash to accept live:MEMORY-IMAGE[@ADDRESS]

Now I can run qemu with the memory-backend-file option and use /usr/bin/crash in "live" mode using the file(s) specified by mem-path argument as a RAM dump. For example, $ qemu-kmv ...other-options... \ -object memory-backend-file,id=MEM,size=128m,mem-path=/tmp/MEM,share=on \ -numa node,memdev=MEM -m 128 and $ crash path-to-guests-vmlinux live:/tmp/MEM@0 NOTE: in this particular (and simple) case the offset is always zero. In more complex situations the ram-to-file mapping used by qemu can be nontrivial, but it is very simple to add the support for MEMORY-IMAGE@ADDRESS-LENGTH syntax. Signed-off-by: Oleg Nesterov <oleg(a)redhat.com&gt; --- defs.h | 7 ++++--- main.c | 9 +++++++++ memory.c | 1 + ramdump.c | 12 ++++++++++++ 4 files changed, 26 insertions(+), 3 deletions(-) diff --git a/defs.h b/defs.h index 1c78c38..61497a5 100644 --- a/defs.h +++ b/defs.h @@ -212,6 +212,7 @@ struct number_option { #define DEVMEM (0x2000000ULL) #define REM_LIVE_SYSTEM (0x4000000ULL) #define NAMELIST_LOCAL (0x8000000ULL) +#define LIVE_RAMDUMP (0x10000000ULL) #define NAMELIST_SAVED (0x20000000ULL) #define DUMPFILE_SAVED (0x40000000ULL) #define UNLINK_NAMELIST (0x80000000ULL) @@ -250,11 +251,11 @@ struct number_option { #define PROC_KCORE (0x8000000000000000ULL) #define ACTIVE() (pc->flags & LIVE_SYSTEM) -#define LOCAL_ACTIVE() ACTIVE() +#define LOCAL_ACTIVE() ((pc->flags & (LIVE_SYSTEM|LIVE_RAMDUMP)) == LIVE_SYSTEM) #define DUMPFILE() (!(pc->flags & LIVE_SYSTEM)) #define LIVE() (pc->flags2 & LIVE_DUMP || pc->flags & LIVE_SYSTEM) -#define MEMORY_SOURCES (NETDUMP|KDUMP|MCLXCD|LKCD|DEVMEM|S390D|MEMMOD|DISKDUMP|XENDUMP|CRASHBUILTIN|KVMDUMP|PROC_KCORE|SADUMP|VMWARE_VMSS) -#define DUMPFILE_TYPES (DISKDUMP|NETDUMP|KDUMP|MCLXCD|LKCD|S390D|XENDUMP|KVMDUMP|SADUMP|VMWARE_VMSS) +#define MEMORY_SOURCES (NETDUMP|KDUMP|MCLXCD|LKCD|DEVMEM|S390D|MEMMOD|DISKDUMP|XENDUMP|CRASHBUILTIN|KVMDUMP|PROC_KCORE|SADUMP|VMWARE_VMSS|LIVE_RAMDUMP) +#define DUMPFILE_TYPES (DISKDUMP|NETDUMP|KDUMP|MCLXCD|LKCD|S390D|XENDUMP|KVMDUMP|SADUMP|VMWARE_VMSS|LIVE_RAMDUMP) #define REMOTE() (pc->flags2 & REMOTE_DAEMON) #define REMOTE_ACTIVE() (pc->flags & REM_LIVE_SYSTEM) #define REMOTE_DUMPFILE() \ diff --git a/main.c b/main.c index a4db88d..075a1e8 100644 --- a/main.c +++ b/main.c @@ -428,6 +428,15 @@ main(int argc, char **argv) "too many dumpfile arguments\n"); program_usage(SHORT_FORM); } + + if (ACTIVE()) { + pc->flags |= LIVE_RAMDUMP; + pc->readmem = read_ramdump; + pc->writemem = NULL; + optind++; + continue; + } + pc->dumpfile = ramdump_to_elf(); if (is_kdump(pc->dumpfile, KDUMP_LOCAL)) { pc->flags |= KDUMP; diff --git a/memory.c b/memory.c index 693516e..aa8be87 100644 --- a/memory.c +++ b/memory.c @@ -16463,6 +16463,7 @@ memory_page_size(void) case CRASHBUILTIN: case KVMDUMP: case PROC_KCORE: + case LIVE_RAMDUMP: psz = (uint)getpagesize(); break; diff --git a/ramdump.c b/ramdump.c index 1922c1b..941851c 100644 --- a/ramdump.c +++ b/ramdump.c @@ -232,14 +232,21 @@ char *ramdump_to_elf(void) return e_file; } +#define PREFIX(ptr, pat) \ + (strncmp((ptr), (pat), sizeof(pat)-1) ? 0 : \ + ((ptr) += sizeof(pat)-1, 1)) + int is_ramdump(char *p) { char *x = NULL, *y = NULL, *pat; size_t len; char *pattern; struct stat64 st; + int is_live; int err = 0; + is_live = PREFIX(p, "live:"); + if (nodes || !strchr(p, '@')) return 0; @@ -276,6 +283,11 @@ int is_ramdump(char *p) pat = NULL; } + if (nodes && is_live) { + pc->flags |= LIVE_SYSTEM; + pc->dumpfile = ramdump[0].path; + pc->live_memsrc = pc->dumpfile; + } return nodes; } -- 2.5.0