-----Original Message----- > Previously for x86_64, when memory is randomized, the region addresses > such as vmalloc_start_addr/vmemmap_vaddr/modules_vaddr are firstly set > to a default value before POST_RELOC phase, then get refreshed with the > actual value in POST_GDB phase. > > However for crash mininal mode, POST_GDB phase is not called, which > leaving the region addresses unrefreshed and incorrect. As a consequence, > the x86_64_IS_VMALLOC_ADDR check will give a faulty result when > value_search tries to search a symbol by address. >

> For example, in crash minimal mode we can observe the following issue: > > crash> dis -f panic > dis: cannot resolve address: ffffffffb20e0d30 > > crash> sym panic > ffffffffb20e0d30 (T) panic /usr/src/debug/kernel-4.18.0-290/linux-4.18.0-290/kernel/panic.c: 168 > crash> sym ffffffffb20e0d30 > symbol not found: ffffffffb20e0d30 > > In this patch, we will move the code which update the region addresses into > POST_RELOC phase, so in mininal mode the regions can get the correct > addresses. > > Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; The patch looks good to me, but with fixing the comment for the if block in POST_RELOC like this: /* - * Check for CONFIG_RANDOMIZE_MEMORY, and set page_offset here. - * The remainder of the virtual address range setups will get - * done below in POST_GDB. + * Check for CONFIG_RANDOMIZE_MEMORY, and set page_offset and + * the virtual address ranges. */ if (kernel_symbol_exists("page_offset_base") && Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt;

Thanks, Kazu > --- > x86_64.c | 52 ++++++++++++++++++++++++++-------------------------- > 1 file changed, 26 insertions(+), 26 deletions(-) > > diff --git a/x86_64.c b/x86_64.c > index 552d619..2fb1277 100644 > --- a/x86_64.c > +++ b/x86_64.c > @@ -384,6 +384,31 @@ x86_64_init(int when) > "page_offset_base", QUIET|FAULT_ON_ERROR); > machdep->kvbase = machdep->machspec->page_offset; > machdep->identity_map_base = machdep->machspec->page_offset; > + > + readmem(symbol_value("vmalloc_base"), KVADDR, > + &machdep->machspec->vmalloc_start_addr, > + sizeof(ulong), "vmalloc_base", FAULT_ON_ERROR); > + if (machdep->flags & VM_5LEVEL) > + machdep->machspec->vmalloc_end = > + machdep->machspec->vmalloc_start_addr + TERABYTES(1280) - 1; > + else > + machdep->machspec->vmalloc_end = > + machdep->machspec->vmalloc_start_addr + TERABYTES(32) - 1; > + if (kernel_symbol_exists("vmemmap_base")) { > + readmem(symbol_value("vmemmap_base"), KVADDR, > + &machdep->machspec->vmemmap_vaddr, sizeof(ulong), > + "vmemmap_base", FAULT_ON_ERROR); > + machdep->machspec->vmemmap_end = > + machdep->machspec->vmemmap_vaddr + > + TERABYTES(1) - 1; > + } else { > + machdep->machspec->vmemmap_vaddr = VMEMMAP_VADDR_2_6_31; > + machdep->machspec->vmemmap_end = VMEMMAP_END_2_6_31; > + } > + machdep->machspec->modules_vaddr = __START_KERNEL_map + > + (machdep->machspec->kernel_image_size ? > + machdep->machspec->kernel_image_size : GIGABYTES(1)); > + machdep->machspec->modules_end = MODULES_END_2_6_31; > } > break; > > @@ -414,32 +439,7 @@ x86_64_init(int when) > machdep->machspec->modules_end = MODULES_END_2_6_27; > } > if (THIS_KERNEL_VERSION >= LINUX(2,6,31)) { > - if (machdep->flags & RANDOMIZED) { > - readmem(symbol_value("vmalloc_base"), KVADDR, > - &machdep->machspec->vmalloc_start_addr, > - sizeof(ulong), "vmalloc_base", FAULT_ON_ERROR); > - if (machdep->flags & VM_5LEVEL) > - machdep->machspec->vmalloc_end = > - machdep->machspec->vmalloc_start_addr + TERABYTES(1280) - 1; > - else > - machdep->machspec->vmalloc_end = > - machdep->machspec->vmalloc_start_addr + TERABYTES(32) - 1; > - if (kernel_symbol_exists("vmemmap_base")) { > - readmem(symbol_value("vmemmap_base"), KVADDR, > - &machdep->machspec->vmemmap_vaddr, sizeof(ulong), > - "vmemmap_base", FAULT_ON_ERROR); > - machdep->machspec->vmemmap_end = > - machdep->machspec->vmemmap_vaddr + > - TERABYTES(1) - 1; > - } else { > - machdep->machspec->vmemmap_vaddr = VMEMMAP_VADDR_2_6_31; > - machdep->machspec->vmemmap_end = VMEMMAP_END_2_6_31; > - } > - machdep->machspec->modules_vaddr = __START_KERNEL_map + > - (machdep->machspec->kernel_image_size ? > - machdep->machspec->kernel_image_size : GIGABYTES(1)); > - machdep->machspec->modules_end = MODULES_END_2_6_31; > - } else { > + if (!(machdep->flags & RANDOMIZED)) { > machdep->machspec->vmalloc_start_addr = VMALLOC_START_ADDR_2_6_31; > machdep->machspec->vmalloc_end = VMALLOC_END_2_6_31; > machdep->machspec->vmemmap_vaddr = VMEMMAP_VADDR_2_6_31; > -- > 2.33.1 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://listman.redhat.com/mailman/listinfo/crash-utility