mirror of
https://github.com/torvalds/linux
synced 2024-09-20 02:57:25 +00:00
08d0ce30e0
Commitf0bddf5058("riscv: entry: Convert to generic entry") moved syscall handling to C code, which exposed function pointer type mismatches that trip fine-grained forward-edge Control-Flow Integrity (CFI) checks as syscall handlers are all called through the same syscall_t pointer type. To fix the type mismatches, implement pt_regs based syscall wrappers similarly to x86 and arm64. This patch is based on arm64 syscall wrappers added in commit4378a7d4be("arm64: implement syscall wrappers"), where the main goal was to minimize the risk of userspace-controlled values being used under speculation. This may be a concern for riscv in future as well. Following other architectures, the syscall wrappers generate three functions for each syscall; __riscv_<compat_>sys_<name> takes a pt_regs pointer and extracts arguments from registers, __se_<compat_>sys_<name> is a sign-extension wrapper that casts the long arguments to the correct types for the real syscall implementation, which is named __do_<compat_>sys_<name>. Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230710183544.999540-9-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
88 lines
3.2 KiB
C
88 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* syscall_wrapper.h - riscv specific wrappers to syscall definitions
|
|
*
|
|
* Based on arch/arm64/include/syscall_wrapper.h
|
|
*/
|
|
|
|
#ifndef __ASM_SYSCALL_WRAPPER_H
|
|
#define __ASM_SYSCALL_WRAPPER_H
|
|
|
|
#include <asm/ptrace.h>
|
|
|
|
asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
|
|
|
|
#define SC_RISCV_REGS_TO_ARGS(x, ...) \
|
|
__MAP(x,__SC_ARGS \
|
|
,,regs->orig_a0,,regs->a1,,regs->a2 \
|
|
,,regs->a3,,regs->a4,,regs->a5,,regs->a6)
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
|
|
asmlinkage long __riscv_compat_sys##name(const struct pt_regs *regs); \
|
|
ALLOW_ERROR_INJECTION(__riscv_compat_sys##name, ERRNO); \
|
|
static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
|
|
static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
|
|
asmlinkage long __riscv_compat_sys##name(const struct pt_regs *regs) \
|
|
{ \
|
|
return __se_compat_sys##name(SC_RISCV_REGS_TO_ARGS(x,__VA_ARGS__)); \
|
|
} \
|
|
static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
|
|
{ \
|
|
return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
|
|
} \
|
|
static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
|
|
|
|
#define COMPAT_SYSCALL_DEFINE0(sname) \
|
|
asmlinkage long __riscv_compat_sys_##sname(const struct pt_regs *__unused); \
|
|
ALLOW_ERROR_INJECTION(__riscv_compat_sys_##sname, ERRNO); \
|
|
asmlinkage long __riscv_compat_sys_##sname(const struct pt_regs *__unused)
|
|
|
|
#define COND_SYSCALL_COMPAT(name) \
|
|
asmlinkage long __weak __riscv_compat_sys_##name(const struct pt_regs *regs); \
|
|
asmlinkage long __weak __riscv_compat_sys_##name(const struct pt_regs *regs) \
|
|
{ \
|
|
return sys_ni_syscall(); \
|
|
}
|
|
|
|
#define COMPAT_SYS_NI(name) \
|
|
SYSCALL_ALIAS(__riscv_compat_sys_##name, sys_ni_posix_timers);
|
|
|
|
#endif /* CONFIG_COMPAT */
|
|
|
|
#define __SYSCALL_DEFINEx(x, name, ...) \
|
|
asmlinkage long __riscv_sys##name(const struct pt_regs *regs); \
|
|
ALLOW_ERROR_INJECTION(__riscv_sys##name, ERRNO); \
|
|
static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
|
|
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
|
|
asmlinkage long __riscv_sys##name(const struct pt_regs *regs) \
|
|
{ \
|
|
return __se_sys##name(SC_RISCV_REGS_TO_ARGS(x,__VA_ARGS__)); \
|
|
} \
|
|
static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
|
|
{ \
|
|
long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
|
|
__MAP(x,__SC_TEST,__VA_ARGS__); \
|
|
__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
|
|
return ret; \
|
|
} \
|
|
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
|
|
|
|
#define SYSCALL_DEFINE0(sname) \
|
|
SYSCALL_METADATA(_##sname, 0); \
|
|
asmlinkage long __riscv_sys_##sname(const struct pt_regs *__unused); \
|
|
ALLOW_ERROR_INJECTION(__riscv_sys_##sname, ERRNO); \
|
|
asmlinkage long __riscv_sys_##sname(const struct pt_regs *__unused)
|
|
|
|
#define COND_SYSCALL(name) \
|
|
asmlinkage long __weak __riscv_sys_##name(const struct pt_regs *regs); \
|
|
asmlinkage long __weak __riscv_sys_##name(const struct pt_regs *regs) \
|
|
{ \
|
|
return sys_ni_syscall(); \
|
|
}
|
|
|
|
#define SYS_NI(name) SYSCALL_ALIAS(__riscv_sys_##name, sys_ni_posix_timers);
|
|
|
|
#endif /* __ASM_SYSCALL_WRAPPER_H */
|