TARGET_NR_mlock2 is defined for every target's syscall table (it has been available on all Linux architectures since it was added in kernel 4.4), and linux-user/strace.list already has an entry for it, but linux-user/syscall.c has no case handler for it. A guest mlock2() call therefore falls through to the default case and gets -ENOSYS instead of being emulated, on every target.
mlock2() differs from mlock() only by a third `flags` argument (MLOCK_ONFAULT). Add TARGET_MLOCK_ONFAULT and a case that validates the flags argument and forwards to the host mlock2(), mirroring the existing TARGET_NR_mlock case immediately above it. Signed-off-by: Michael Morrell <[email protected]> --- linux-user/syscall.c | 9 +++++++++ linux-user/syscall_defs.h | 4 ++++ 2 files changed, 13 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index cfa68dfbdb..9f454502cb 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11230,6 +11230,15 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, case TARGET_NR_mlock: return get_errno(mlock(g2h(cpu, arg1), arg2)); #endif +#ifdef TARGET_NR_mlock2 + case TARGET_NR_mlock2: + if (arg3 & ~TARGET_MLOCK_ONFAULT) { + return -TARGET_EINVAL; + } + return get_errno(mlock2(g2h(cpu, arg1), arg2, + (arg3 & TARGET_MLOCK_ONFAULT) ? + MLOCK_ONFAULT : 0)); +#endif #ifdef TARGET_NR_munlock case TARGET_NR_munlock: return get_errno(munlock(g2h(cpu, arg1), arg2)); diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index e28853c93b..f5831a6bad 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -2795,6 +2795,10 @@ struct target_mount_attr_ver0 { #ifndef RESOLVE_IN_ROOT #define RESOLVE_IN_ROOT 0x10 #endif + +/* flags for mlock2() */ +#define TARGET_MLOCK_ONFAULT 0x01 + #if (defined(TARGET_I386) && defined(TARGET_ABI32)) || \ (defined(TARGET_ARM) && defined(TARGET_ABI32)) || \ defined(TARGET_M68K) || defined(TARGET_MICROBLAZE) || \ -- 2.43.0
