On Thu, Nov 19, 2015 at 11:50:22AM -0500, Dave Anderson wrote: > > > ----- Original Message ----- > > QEMU can generate both non-makedumpfile (just elf) and makedumpfile > > formatted kdumps. In neither case will crash_notes have prstatus, as > > crash_kexec doesn't run in the kernel, however the elf notes will > > contain the prstatus, and we can dig them out of there. > > Hi Andrew, > > Refresh my memory -- without the patch, what does "bt" do when run > against the active tasks from QEMU generated dumps? On initial loading a couple warnings are output WARNING: invalid note (n_type != NT_PRSTATUS) WARNING: cannot retrieve registers for active tasks When attempting 'bt', crash segfaults PID: 2424 TASK: ffffffc057a46e00 CPU: 1 COMMAND: "bash" bt: WARNING: cannot determine starting stack frame for task ffffffc057a46e00 Segmentation fault Thanks, drew > > Dave > > > > --- > > arm.c | 22 ++++++++++++++++++++++ > > arm64.c | 22 ++++++++++++++++++++++ > > defs.h | 1 + > > netdump.c | 21 +++++++++++++++++++++ > > 4 files changed, 66 insertions(+) > > > > diff --git a/arm.c b/arm.c > > index ffc7c06d0f42c..8fc3d48a8ac89 100644 > > --- a/arm.c > > +++ b/arm.c > > @@ -597,6 +597,28 @@ arm_get_crash_notes(void) > > note = (Elf32_Nhdr *)buf; > > p = buf + sizeof(Elf32_Nhdr); > > > > + /* > > + * dumpfiles created with qemu won't have crash_notes, but there will > > + * be elf notes. > > + */ > > + if (note->n_namesz == 0 && (DISKDUMP_DUMPFILE() || KDUMP_DUMPFILE())) { > > + if (DISKDUMP_DUMPFILE()) > > + note = diskdump_get_prstatus_percpu(i); > > + else if (KDUMP_DUMPFILE()) > > + note = netdump_get_prstatus_percpu(i); > > + if (note) { > > + /* > > + * SIZE(note_buf) accounts for a "final note", which is a > > + * trailing empty elf note header. > > + */ > > + long notesz = SIZE(note_buf) - sizeof(Elf32_Nhdr); > > + > > + if (sizeof(Elf32_Nhdr) + roundup(note->n_namesz, 4) + > > + note->n_descsz == notesz) > > + BCOPY((char *)note, buf, notesz); > > + } > > + } > > + > > if (note->n_type != NT_PRSTATUS) { > > error(WARNING, "invalid note (n_type != NT_PRSTATUS)\n"); > > goto fail; > > diff --git a/arm64.c b/arm64.c > > index 6187b96d25a4d..91b35787e6942 100644 > > --- a/arm64.c > > +++ b/arm64.c > > @@ -1827,6 +1827,28 @@ arm64_get_crash_notes(void) > > note = (Elf64_Nhdr *)buf; > > p = buf + sizeof(Elf64_Nhdr); > > > > + /* > > + * dumpfiles created with qemu won't have crash_notes, but there will > > + * be elf notes. > > + */ > > + if (note->n_namesz == 0 && (DISKDUMP_DUMPFILE() || KDUMP_DUMPFILE())) { > > + if (DISKDUMP_DUMPFILE()) > > + note = diskdump_get_prstatus_percpu(i); > > + else if (KDUMP_DUMPFILE()) > > + note = netdump_get_prstatus_percpu(i); > > + if (note) { > > + /* > > + * SIZE(note_buf) accounts for a "final note", which is a > > + * trailing empty elf note header. > > + */ > > + long notesz = SIZE(note_buf) - sizeof(Elf64_Nhdr); > > + > > + if (sizeof(Elf64_Nhdr) + roundup(note->n_namesz, 4) + > > + note->n_descsz == notesz) > > + BCOPY((char *)note, buf, notesz); > > + } > > + } > > + > > if (note->n_type != NT_PRSTATUS) { > > error(WARNING, "invalid note (n_type != NT_PRSTATUS)\n"); > > goto fail; > > diff --git a/defs.h b/defs.h > > index 1bcd1b3b177db..981b030cc6688 100644 > > --- a/defs.h > > +++ b/defs.h > > @@ -5722,6 +5722,7 @@ void dump_registers_for_qemu_mem_dump(void); > > void kdump_backup_region_init(void); > > void display_regs_from_elf_notes(int, FILE *); > > void display_ELF_note(int, int, void *, FILE *); > > +void *netdump_get_prstatus_percpu(int); > > #define PRSTATUS_NOTE (1) > > #define QEMU_NOTE (2) > > > > diff --git a/netdump.c b/netdump.c > > index bfa818fdef8e1..3ff49f0577c23 100644 > > --- a/netdump.c > > +++ b/netdump.c > > @@ -2345,6 +2345,27 @@ dump_Elf64_Nhdr(Elf64_Off offset, int store) > > return len; > > } > > > > +void * > > +netdump_get_prstatus_percpu(int cpu) > > +{ > > + int online; > > + > > + if ((cpu < 0) || (cpu >= nd->num_prstatus_notes)) > > + return NULL; > > + > > + /* > > + * If no cpu mapping was done, then there must be > > + * a one-to-one relationship between the number > > + * of online cpus and the number of notes. > > + */ > > + if ((online = get_cpus_online()) && > > + (online == kt->cpus) && > > + (online != nd->num_prstatus_notes)) > > + return NULL; > > + > > + return nd->nt_prstatus_percpu[cpu]; > > +} > > + > > /* > > * Send the request to the proper architecture hander. > > */ > > -- > > 2.4.3 > > > > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility