diff options
| -rw-r--r-- | include/linux/compat.h | 22 | ||||
| -rw-r--r-- | init/Kconfig | 9 | ||||
| -rw-r--r-- | kernel/sys_ni.c | 10 | ||||
| -rw-r--r-- | kernel/time/posix-stubs.c | 10 |
4 files changed, 48 insertions, 3 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index 9847c5a013c3..2d85ec5cfda2 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -24,6 +24,17 @@ #include <asm/siginfo.h> #include <asm/signal.h> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +/* + * It may be useful for an architecture to override the definitions of the + * COMPAT_SYSCALL_DEFINE0 and COMPAT_SYSCALL_DEFINEx() macros, in particular + * to use a different calling convention for syscalls. To allow for that, + + the prototypes for the compat_sys_*() functions below will *not* be included + * if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. + */ +#include <asm/syscall_wrapper.h> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + #ifndef COMPAT_USE_64BIT_TIME #define COMPAT_USE_64BIT_TIME 0 #endif @@ -32,10 +43,12 @@ #define __SC_DELOUSE(t,v) ((__force t)(unsigned long)(v)) #endif +#ifndef COMPAT_SYSCALL_DEFINE0 #define COMPAT_SYSCALL_DEFINE0(name) \ asmlinkage long compat_sys_##name(void); \ ALLOW_ERROR_INJECTION(compat_sys_##name, ERRNO); \ asmlinkage long compat_sys_##name(void) +#endif /* COMPAT_SYSCALL_DEFINE0 */ #define COMPAT_SYSCALL_DEFINE1(name, ...) \ COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) @@ -50,6 +63,7 @@ #define COMPAT_SYSCALL_DEFINE6(name, ...) \ COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) +#ifndef COMPAT_SYSCALL_DEFINEx #define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\ @@ -62,6 +76,7 @@ return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \ } \ static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)) +#endif /* COMPAT_SYSCALL_DEFINEx */ #ifndef compat_user_stack_pointer #define compat_user_stack_pointer() current_user_stack_pointer() @@ -517,7 +532,12 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long); * Please note that these prototypes here are only provided for information * purposes, for static analysis, and for linking from the syscall table. * These functions should not be called elsewhere from kernel code. + * + * As the syscall calling convention may be different from the default + * for architectures overriding the syscall calling convention, do not + * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. */ +#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER asmlinkage long compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p); asmlinkage long compat_sys_io_submit(compat_aio_context_t ctx_id, int nr, u32 __user *iocb); @@ -955,6 +975,8 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr); /* obsolete: net/socket.c */ asmlinkage long compat_sys_socketcall(int call, u32 __user *args); +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + /* * For most but not all architectures, "am I in a compat syscall?" and diff --git a/init/Kconfig b/init/Kconfig index 068eb6c3bbf7..2dbc88051bde 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1925,8 +1925,11 @@ config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE bool # It may be useful for an architecture to override the definitions of the -# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>, -# in particular to use a different calling convention for syscalls. +# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h> +# and the COMPAT_ variants in <linux/compat.h>, in particular to use a +# different calling convention for syscalls. They can also override the +# macros for not-implemented syscalls in kernel/sys_ni.c and +# kernel/time/posix-stubs.c. All these overrides need to be available in +# <asm/syscall_wrapper.h>. config ARCH_HAS_SYSCALL_WRAPPER def_bool n - depends on !COMPAT diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 6cafc008f6db..9791364925dc 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -5,6 +5,11 @@ #include <asm/unistd.h> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +/* Architectures may override COND_SYSCALL and COND_SYSCALL_COMPAT */ +#include <asm/syscall_wrapper.h> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + /* we can't #include <linux/syscalls.h> here, but tell gcc to not warn with -Wmissing-prototypes */ asmlinkage long sys_ni_syscall(void); @@ -17,8 +22,13 @@ asmlinkage long sys_ni_syscall(void) return -ENOSYS; } +#ifndef COND_SYSCALL #define COND_SYSCALL(name) cond_syscall(sys_##name) +#endif /* COND_SYSCALL */ + +#ifndef COND_SYSCALL_COMPAT #define COND_SYSCALL_COMPAT(name) cond_syscall(compat_sys_##name) +#endif /* COND_SYSCALL_COMPAT */ /* * This list is kept in the same order as include/uapi/asm-generic/unistd.h. diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c index b258bee13b02..69a937c3cd81 100644 --- a/kernel/time/posix-stubs.c +++ b/kernel/time/posix-stubs.c @@ -19,6 +19,11 @@ #include <linux/posix-timers.h> #include <linux/compat.h> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +/* Architectures may override SYS_NI and COMPAT_SYS_NI */ +#include <asm/syscall_wrapper.h> +#endif + asmlinkage long sys_ni_posix_timers(void) { pr_err_once("process %d (%s) attempted a POSIX timer syscall " @@ -27,8 +32,13 @@ asmlinkage long sys_ni_posix_timers(void) return -ENOSYS; } +#ifndef SYS_NI #define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers) +#endif + +#ifndef COMPAT_SYS_NI #define COMPAT_SYS_NI(name) SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers) +#endif SYS_NI(timer_create); SYS_NI(timer_gettime); |