On 2014/5/20 20:51, Dave Anderson wrote: > > > ----- Original Message ----- >> >> On 2014/5/20 3:41, Dave Anderson wrote: >>> >>> >>> ----- Original Message ----- >>>> >>>> Hi Atsushi and Simon, >>>> >>>> I find a problem about VMSPLIT on arm plarform, related to kexec and >>>> makedumpfile. >>>> >>>> When CONFIG_VMSPLIT_1G/2G is selected by kernel, PAGE_OFFSET is actually >>>> 0x40000000 or 0x80000000. However, kexec hard codes PAGE_OFFSET to >>>> 0xc0000000 (in kexec/arch/arm/crashdump-arm.h), which is incorrect in >>>> these situations. For example, on realview-pbx board with 1G/3G VMSPLIT, >>>> PHDRs in generated /proc/vmcore is as follow: >>>> >>>> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align >>>> NOTE 0x001000 0x00000000 0x00000000 0x00690 0x00690 0 >>>> LOAD 0x002000 0xc0000000 0x00000000 0x10000000 0x10000000 RWE >>>> 0 >>>> LOAD 0x10002000 0xe0000000 0x20000000 0x8000000 0x8000000 RWE >>>> 0 >>>> LOAD 0x18002000 0xf0000000 0x30000000 0x10000000 0x10000000 >>>> RWE 0 >>>> LOAD 0x28002000 0x40000000 0x80000000 0x10000000 0x10000000 >>>> RWE 0 >>>> >>>> Which should be: >>>> >>>> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align >>>> ... >>>> LOAD ... 0x40000000 0x00000000 0x10000000 0x10000000 RWE >>>> 0 >>>> LOAD ... 0x60000000 0x20000000 0x8000000 0x8000000 RWE 0 >>>> LOAD ... 0x70000000 0x30000000 0x10000000 0x10000000 RWE >>>> 0 >>>> LOAD ... 0xc0000000 0x80000000 0x10000000 0x10000000 RWE >>>> 0 >>>> >>>> I don't know why crash utility can deal with it without problem, >>> >>> For ARM the crash utility masks the symbol value of "_stext" with 0x1fffffff >>> to determine the PAGE_OFFSET value, which was basically copied from the way >>> it was done for i386. >>> >> >> kexec-tools can do the same thing by reading /proc/kallsyms (crashdump-x86.c has already done this). >> However, KALLSYMS and KALLSYMS_ALL are turned off on some embedded systems with memory limitation, >> which is common on ARM. > > But you could use VMCOREINFO_SYMBOL(_stext), right? > makedumpfile can use it, but not for kexec-tools. > Dave > >
