kernel/arch/s390/include/asm/syscall_wrapper.h, branch linux-5.14.y

s390: pass struct pt_regs instead of registers to syscalls

2021-01-19T11:29:27Z

Instead of fetching all registers from struct pt_regs and passing them to the syscall wrappers, let the system call wrappers only fetch the values really required. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: remove asmlinkage

2021-01-19T11:29:26Z

On s390 asmlinkage is a nop, so remove it. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: enable HAVE_FUNCTION_ERROR_INJECTION

2020-07-27T08:33:28Z

This kernel feature is required for enabling BPF_KPROBE_OVERRIDE. Define override_function_with_return() and regs_set_return_value() functions, and fix compile errors in syscall_wrapper.h. Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens

s390: syscall_wrapper: avoid clang warning

2019-04-11T11:36:51Z

Building system calls with clang results in a warning about an alias from a global function to a static one: ../fs/namei.c:3847:1: warning: unused function '__se_sys_mkdirat' [-Wunused-function] SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) ^ ../include/linux/syscalls.h:219:36: note: expanded from macro 'SYSCALL_DEFINE3' #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__) ^ ../include/linux/syscalls.h:228:2: note: expanded from macro 'SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^ ../arch/s390/include/asm/syscall_wrapper.h:126:18: note: expanded from macro '__SYSCALL_DEFINEx' asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^ :31:1: note: expanded from here __se_sys_mkdirat ^ The only reference to the static __se_sys_mkdirat() here is the alias, but this only gets evaluated later. Making this function global as well avoids the warning. Signed-off-by: Arnd Bergmann Signed-off-by: Martin Schwidefsky

s390: autogenerate compat syscall wrappers

2019-01-18T08:33:19Z

Any system call that takes a pointer argument on s390 requires a wrapper function to do a 31-to-64 zero-extension, these are currently generated in arch/s390/kernel/compat_wrapper.c. On arm64 and x86, we already generate similar wrappers for all system calls in the place of their definition, just for a different purpose (they load the arguments from pt_regs). We can do the same thing here, by adding an asm/syscall_wrapper.h file with a copy of all the relevant macros to override the generic version. Besides the addition of the compat entry point, these also rename the entry points with a __s390_ or __s390x_ prefix, similar to what we do on arm64 and x86. This in turn requires renaming a few things, and adding a proper ni_syscall() entry point. In order to still compile system call definitions that pass an loff_t argument, the __SC_COMPAT_CAST() macro checks for that and forces an -ENOSYS error, which was the best I could come up with. Those functions must obviously not get called from user space, but instead require hand-written compat_sys_*() handlers, which fortunately already exist. Link: https://lore.kernel.org/lkml/20190116131527.2071570-5-arnd@arndb.de Signed-off-by: Arnd Bergmann Reviewed-by: Heiko Carstens [heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT] Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky