The problem that makes us use wrappers is that some compat architectures allows user code to access top halves of registers. This is not a problem for syscalls that are already handled by compat code, or for that who has types of the same size in kernel and userspace. In case of s390 and lp64/ilp32 the problem is in pointer types, long, unsigned long. S390 folks already have the solution for it. In this patchset, it is turned to be general, as arm64/ilp32 needs it too. This patchset is created as the part of the work of enabling arm64 with ILP32 user mode. See details here: http://thread.gmane.org/gmane.linux.kernel/2126946 This is the implementation of one of two possible approaches. First one defines new syscall handler declaration macro, that creates both compat and non-compat handlers, see [1]. This one declares all wrappers in separated file kernel/compat_wrapper.c Build-tested on s390. [1] http://www.spinics.net/lists/linux-s390/msg11593.html Yury Norov (5): all: syscall wrappers: add documentation all: introduce COMPAT_WRAPPER option and enable it for s390 all: s390: move wrapper infrastructure to generic headers all: s390: move compat_wrappers.c from arch/s390/kernel to kernel/ all: wrap needed syscalls in generic unistd Documentation/adding-syscalls.txt | 32 +++++ arch/Kconfig | 4 + arch/s390/Kconfig | 1 + arch/s390/include/asm/compat.h | 17 ++- arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/compat_wrapper.c | 180 ------------------------ include/linux/compat.h | 278 ++++++++++++++++++++++++++++++++++++++ include/linux/syscalls.h | 57 +------- include/linux/syscalls_structs.h | 60 ++++++++ include/uapi/asm-generic/unistd.h | 231 +++++++++++++++---------------- kernel/Makefile | 1 + kernel/compat_wrapper.c | 170 +++++++++++++++++++++++ 12 files changed, 680 insertions(+), 353 deletions(-) delete mode 100644 arch/s390/kernel/compat_wrapper.c create mode 100644 include/linux/syscalls_structs.h create mode 100644 kernel/compat_wrapper.c -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
