Re: [Crash-utility] [PATCH 2/2] memory_driver: Support overriding kernel directory

Hi Lianbo, Thanks for testing! My response is inline below... On 27.09.23 11:14, lijiang wrote: > Hi, Mathias > Thank you for the patchset. > On Tue, Sep 26, 2023 at 10:36 PM <crash-utility-request(a)redhat.com > <mailto:crash-utility-request@redhat.com>> wrote: > > Date: Tue, 26 Sep 2023 12:12:47 +0200 > From: Mathias Krause <minipli(a)grsecurity.net > <mailto:minipli@grsecurity.net>> > To: crash-utility(a)redhat.com <mailto:crash-utility@redhat.com> > Subject: [Crash-utility] [PATCH 2/2] memory_driver: Support overriding > kernel directory > Message-ID: <20230926101247.1237748-3-minipli(a)grsecurity.net > <mailto:20230926101247.1237748-3-minipli@grsecurity.net>> > Content-Type: text/plain; charset="US-ASCII"; x-default=true > > Support compiling the module against a different kernel version than the > currently running one by allowing to set either KVER or KDIR variables > on the make commandline. > > Also modernize the makefile slightly and make use of the kernel's > 'clean' target to ensure to remove all generated files. > > > The [PATCH 1/2] looks good to me. Thanks. > > For the [PATCH 2/2], I only have two questions: > > [1] With the patch 2/2, it always triggers recompiling the gdb like this: > # make lzo > TARGET: PPC64 > CRASH: 8.0.3++ > GDB: 10.2 > > CXX gdb.o > CXX ../../crash_target.o > CXX ada-exp.o > CXX ada-lang.o > CXX ada-tasks.o > CXX ada-typeprint.o > CXX ada-valprint.o > CXX ada-varobj.o > CXX addrmap.o > CXX agent.o > CXX alloc.o > CXX annotate.o > ... Hmm, I cannot reproduce this. If I do 'make lzo' it builds 'crash' only once, not multiple times as you're observing. Can you please provide instructions how to reproduce the issue? Or, maybe, it's related to the second one...

> [2] With the patch 2/2, it always reports the following error "No such > file or directory", if the kernel-devel package is not installed. > # make clean > ... > make -C /lib/modules/xxx/build M=/home/crash SUBDIRS=/home/crash clean > || rm -f *.mod.c *.ko *.o Module.* > make[3]: *** /lib/modules/xxx/build: No such file or directory. Stop. > > Actually, I did not build the crash.ko in the directory memory_driver/. > > Is that expected behavior? Ahh, yes. That's expected, but unfortunate behavior. I'll fix it by testing if the build directory exists first to avoid the error message. The fall-back handling is already there -- simply does the old 'rm *.mod.c *.ko *.o Module.*'. However, there's no need to generate an error message when we know in advance that the kernel build directory is missing.