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peter.gantner@×××××××××××××.at wrote: |
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> In a LKML post [1] about the symlinking of /usr/include/linux to |
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> /usr/src/linux/include/ which has been done for quite some time in older |
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> Linux distributions, Linus calls doing this "instanity" and states that |
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> the kernel headers used to compile glibc and friends should always be |
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> taken from the glibc distribution (which includes a patched set of |
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> kernel headers) and one should not use the headers from the kernel.org |
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> tarball. |
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You misread what he said (see below). |
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> But this is exactly what Gentoos linux-headers package does: get the |
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> kernel tarball and install the required files. The result is in effect |
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> not really different from the old symlinking method. |
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It is. |
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> Now am I misreading Linus' recommendation? |
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> When he sais: |
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> |
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>> Basically, that symlink should not be a symlink. It's a symlink for |
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>> historical reasons, none of them very good any more (and haven't been |
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>> for a long time), and it's a disaster unless you want to be a C |
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>> library developer. Which not very many people want to be. |
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> |
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>> The fact is, that the header files should match the library you link |
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>> against, not the kernel you run on. |
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That's the important sentence. |
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> and later: |
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> |
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>> [...] you should not use the kernel headers: You should use the |
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>> headers that glibc came with. It is probably a Red Hat bug that those |
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>> headers were a symbolic link. |
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> |
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> |
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> Does that mean: |
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> a) glibc comes with patched kernel headers that should always be used |
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> when compiling other applications/libs |
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> or |
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> b) it doesn't matter what kernel headers you use to build your glibc |
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> with as long as any apps that use glibc use the very same headers at |
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> compile time. |
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b) |
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The point is that all libraries/applications should use the same |
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headers. When you make a symlink the headers are changed on every kernel |
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upgrade, so applications using those headers (in theory only glibc and |
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kernel related applications should directly use those headers, but lets |
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ignore that for now) might have a different idea about data structures |
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than glibc, and that can result in very weird (and possibly serious) |
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problems. |
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|
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Marius |
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-- |
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