kpatch:use vmlinux from first build #1313
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We can use the first compiled vmlinux file from origin source code, and get the gcc version from the config file ，so we don't have to download kernel debuginfo(it's too big),and use kpatch-build command without '-v' Signed-off-by: yinbinbin <yinbinbin001@linux.alibaba.com>
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This is an interesting approach. If the original vmlinux isn't needed for the --sourcedir option, then it shouldn't be needed for any of the distro-specific options, and maybe we can just get rid of the --vmlinux option altogether, as well as the need for the debuginfo RPM.
Also, I think this highlights an existing bug in kpatch-build for the --sourcedir case where the vmlinux is in $USERSRCDIR. It reads the symbol table from the patched version of vmlinux, which could be dangerous if the patch altered the symbol table.
kernel_version < 4.18 get version from vmlinux(debuginfo) kernel_version >= 4.18 get version from config file Signed-off-by: yinbinbin <yinbinbin001@linux.alibaba.com>
if "$VMLINUX" equal "$KERNEL_SRCDIR"/vmlinux file ， kpatch-build will save original vmlinux before it gets overwritten |
But it's not restored before |
Never mind, I now see that VMLINUX gets changed to the original vmlinux in |
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I'm actually thinking we should try a slightly different approach. There have been occasional bugs that caused the original vmlinux and the first compiled vmlinux to differ. See for example the commit log for commit 2e99d6b. Or, they could differ because the user made a mistake by using the wrong version of code or toolchain. Not having the old vmlinux would remove our ability to detect such cases. In fact, I'd like to improve that detection by doing an explicit comparison of their symbol tables. Though, in addition we could add a I'll open another PR with the proposed approach. |
So it turns out that on powerpc and s390 the symbol tables can get shuffled around when you add |
We can use the first compiled vmlinux file from origin source code, and get the gcc version from the config file ，so we don't have to download kernel debuginfo(it's too big),and use kpatch-build command without '-v'
Signed-off-by: yinbinbin yinbinbin001@linux.alibaba.com