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The behavior of these system calls is slightly different between architectures, as determined by the CONFIG_ARCH_WANT_IPC_PARSE_VERSION symbol. Most architectures that implement the split IPC syscalls don't set that symbol and only get the modern version, but alpha, arm, microblaze, mips-n32, mips-n64 and xtensa expect the caller to pass the IPC_64 flag. For the architectures that so far only implement sys_ipc(), i.e. m68k, mips-o32, powerpc, s390, sh, sparc, and x86-32, we want the new behavior when adding the split syscalls, so we need to distinguish between the two groups of architectures. The method I picked for this distinction is to have a separate system call entry point: sys_old_*ctl() now uses ipc_parse_version, while sys_*ctl() does not. The system call tables of the five architectures are changed accordingly. As an additional benefit, we no longer need the configuration specific definition for ipc_parse_version(), it always does the same thing now, but simply won't get called on architectures with the modern interface. A small downside is that on architectures that do set ARCH_WANT_IPC_PARSE_VERSION, we now have an extra set of entry points that are never called. They only add a few bytes of bloat, so it seems better to keep them compared to adding yet another Kconfig symbol. I considered adding new syscall numbers for the IPC_64 variants for consistency, but decided against that for now. Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
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| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
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| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.