diff options
| author | Michael Weiser <michael.weiser@gmx.de> | 2018-02-01 23:13:37 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-03-05 12:06:43 +0000 |
| commit | 532826f3712b607256eb30f92f23d1c604d3fa34 (patch) | |
| tree | dd6212345eb15ff81dbfebbe0a8e9b30411e3f23 /arch/arm64/kernel/sys_compat.c | |
| parent | 4a3928c6f8a53fa1aed28ccba227742486e8ddcb (diff) | |
arm64: Mirror arm for unimplemented compat syscalls
Mirror arm behaviour for unimplemented syscalls: Below 2048 return
-ENOSYS, above 2048 raise SIGILL.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
[will: Tweak die string to identify as compat syscall]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/sys_compat.c')
| -rw-r--r-- | arch/arm64/kernel/sys_compat.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c index a382b2a1b84e..9897f416b29e 100644 --- a/arch/arm64/kernel/sys_compat.c +++ b/arch/arm64/kernel/sys_compat.c @@ -27,6 +27,7 @@ #include <linux/uaccess.h> #include <asm/cacheflush.h> +#include <asm/system_misc.h> #include <asm/unistd.h> static long @@ -67,6 +68,7 @@ do_compat_cache_op(unsigned long start, unsigned long end, int flags) */ long compat_arm_syscall(struct pt_regs *regs) { + siginfo_t info; unsigned int no = regs->regs[7]; switch (no) { @@ -99,6 +101,23 @@ long compat_arm_syscall(struct pt_regs *regs) return 0; default: - return -ENOSYS; + /* + * Calls 9f00xx..9f07ff are defined to return -ENOSYS + * if not implemented, rather than raising SIGILL. This + * way the calling program can gracefully determine whether + * a feature is supported. + */ + if ((no & 0xffff) <= 0x7ff) + return -ENOSYS; + break; } + + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLTRP; + info.si_addr = (void __user *)instruction_pointer(regs) - + (compat_thumb_mode(regs) ? 2 : 4); + + arm64_notify_die("Oops - bad compat syscall(2)", regs, &info, no); + return 0; } |