Re: [Crash-utility] [PATCH] Fix mount command to appropriately display the mount dumps

On 2022/12/21 14:22, HAGIO KAZUHITO(萩尾 一仁) wrote: I think, it might be more helpful to print the MOUNT and SUPERBLK values in the list even if it's zero or invalid, rather than skip it completely. What do you think? e.g. continue here: @@ -1500,6 +1500,11 @@ show_mounts(ulong one_vfsmount, int flags, struct task_context *namespace_contex mkstring(buf2, VADDR_PRLEN, RJUST|LONG_HEX, MKSTR(sbp))); + if (!IS_KVADDR(sbp)) { + error(INFO, "cannot get super_block\n"); + continue; + } + readmem(sbp, KVADDR, super_block_buf, SIZE(super_block), "super_block buffer", FAULT_ON_ERROR); type = ULONG(super_block_buf + OFFSET(super_block_s_type)); Thanks, Kazu > > Thanks, > Kazu > >> >> The kernel virtual address of the super_block is zero when the mount >> command fails at the address 0xffff97b484753420. And the remaining >> dumping information will be discarded. That is not expected. >> >> Check the address and skip it, if this is an invalid kernel virtual >> address, that can avoid truncating the remaining mount dumps. >> >> Reported-by: Dave Wysochanski <dwysocha(a)redhat.com&gt; >> Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; >> --- >> filesys.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/filesys.c b/filesys.c >> index c2ea78de821d..8c2d4e316208 100644 >> --- a/filesys.c >> +++ b/filesys.c >> @@ -1491,6 +1491,8 @@ show_mounts(ulong one_vfsmount, int flags, struct task_context *namespace_contex >> } >> >> sbp = ULONG(vfsmount_buf + OFFSET(vfsmount_mnt_sb)); >> + if (!IS_KVADDR(sbp)) >> + continue; >> >> if (flags) >> fprintf(fp, "%s", mount_hdr); > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://listman.redhat.com/mailman/listinfo/crash-utility > Contribution Guidelines: https://github.com/crash-utility/crash/wiki