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| author | Arnd Bergmann <arnd@arndb.de> | 2019-01-16 14:15:22 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-01-18 09:33:19 +0100 |
| commit | aa0d6e70d3b34e710a6a57a53a3096cb2e0ea99f (patch) | |
| tree | d89caa5e75f4e4c822e26f822208d87d1f0cf719 /arch/s390/kernel/entry.S | |
| parent | fef747bab3c09b30b82f76a391ee0ed83d2d6965 (diff) | |
| download | linux-stable-aa0d6e70d3b34e710a6a57a53a3096cb2e0ea99f.tar.gz linux-stable-aa0d6e70d3b34e710a6a57a53a3096cb2e0ea99f.tar.bz2 linux-stable-aa0d6e70d3b34e710a6a57a53a3096cb2e0ea99f.zip | |
s390: autogenerate compat syscall wrappers
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 <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 39191a0feed1..583d65ef5007 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -1512,7 +1512,7 @@ cleanup_critical: .quad .Lsie_skip - .Lsie_entry #endif .section .rodata, "a" -#define SYSCALL(esame,emu) .long esame +#define SYSCALL(esame,emu) .long __s390x_ ## esame .globl sys_call_table sys_call_table: #include "asm/syscall_table.h" @@ -1520,7 +1520,7 @@ sys_call_table: #ifdef CONFIG_COMPAT -#define SYSCALL(esame,emu) .long emu +#define SYSCALL(esame,emu) .long __s390_ ## emu .globl sys_call_table_emu sys_call_table_emu: #include "asm/syscall_table.h" |