From a3310c0397e21df8f47cde3e55736104b9584d2d Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 15 Nov 2021 14:08:52 +0100 Subject: linux-user: Move syscall error detection into safe_syscall_base The current api from safe_syscall_base() is to return -errno, which is the interface provided by *some* linux kernel abis. The wrapper macro, safe_syscall(), detects error, stores into errno, and returns -1, to match the api of the system syscall(). For those kernel abis that do not return -errno natively, this leads to double syscall error detection. E.g. Linux ppc64, which sets the SO flag for error. Simplify the usage from C by moving the error detection into assembly, and usage from assembly by providing a C helper with which to set errno. Reviewed-by: Warner Losh Signed-off-by: Richard Henderson --- linux-user/safe-syscall.h | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'linux-user/safe-syscall.h') diff --git a/linux-user/safe-syscall.h b/linux-user/safe-syscall.h index aaa9ffc0e2..97837faddb 100644 --- a/linux-user/safe-syscall.h +++ b/linux-user/safe-syscall.h @@ -127,21 +127,15 @@ #ifdef HAVE_SAFE_SYSCALL /* The core part of this function is implemented in assembly */ extern long safe_syscall_base(int *pending, long number, ...); +extern long safe_syscall_set_errno_tail(int value); + /* These are defined by the safe-syscall.inc.S file */ extern char safe_syscall_start[]; extern char safe_syscall_end[]; -#define safe_syscall(...) \ - ({ \ - long ret_; \ - int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \ - ret_ = safe_syscall_base(psp_, __VA_ARGS__); \ - if (is_error(ret_)) { \ - errno = -ret_; \ - ret_ = -1; \ - } \ - ret_; \ - }) +#define safe_syscall(...) \ + safe_syscall_base(&((TaskState *)thread_cpu->opaque)->signal_pending, \ + __VA_ARGS__) #else -- cgit 1.4.1