diff options
Diffstat (limited to 'linux-user/host/x86_64/safe-syscall.inc.S')
| -rw-r--r-- | linux-user/host/x86_64/safe-syscall.inc.S | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/linux-user/host/x86_64/safe-syscall.inc.S b/linux-user/host/x86_64/safe-syscall.inc.S index 158225553e..39b64250c3 100644 --- a/linux-user/host/x86_64/safe-syscall.inc.S +++ b/linux-user/host/x86_64/safe-syscall.inc.S @@ -19,9 +19,6 @@ * first argument an 'int *' to the signal_pending flag, the * second one the system call number (as a 'long'), and all further * arguments being syscall arguments (also 'long'). - * We return a long which is the syscall's return value, which - * may be negative-errno on failure. Conversion to the - * -1-and-errno-set convention is done by the calling wrapper. */ safe_syscall_base: .cfi_startproc @@ -35,9 +32,9 @@ safe_syscall_base: .cfi_adjust_cfa_offset 8 .cfi_rel_offset rbp, 0 - /* The syscall calling convention isn't the same as the - * C one: - * we enter with rdi == *signal_pending + /* + * The syscall calling convention isn't the same as the C one: + * we enter with rdi == &signal_pending * rsi == syscall number * rdx, rcx, r8, r9, (stack), (stack) == syscall arguments * and return the result in rax @@ -68,24 +65,30 @@ safe_syscall_base: safe_syscall_start: /* if signal_pending is non-zero, don't do the call */ cmpl $0, (%rbp) - jnz 1f + jnz 2f syscall safe_syscall_end: /* code path for having successfully executed the syscall */ + cmp $-4095, %rax + jae 0f pop %rbp .cfi_remember_state .cfi_def_cfa_offset 8 .cfi_restore rbp ret + .cfi_restore_state + +0: neg %eax + jmp 1f -1: /* code path when we didn't execute the syscall */ - .cfi_restore_state - mov $-TARGET_ERESTARTSYS, %rax - pop %rbp +2: mov $TARGET_ERESTARTSYS, %eax + + /* code path setting errno */ +1: pop %rbp .cfi_def_cfa_offset 8 .cfi_restore rbp - ret + jmp safe_syscall_set_errno_tail .cfi_endproc .size safe_syscall_base, .-safe_syscall_base |