jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
linux-user: Fix i386 safe-syscall.S
Clang insists that "cmp" is ambiguous with a memory destination,
requiring an explicit size suffix.
There was a true error in the use of .cfi_def_cfa_offset in the
epilogue, but changing to use the proper .cfi_adjust_cfa_offset
runs afoul of a clang bug wrt .cfi_restore_state. Better to
fold the two epilogues so that we don't trigger the bug.
Signed-off-by: Richard Henderson <rth@twiddle.net>
+6
-18
+6
-18
linux-user/host/i386/safe-syscall.inc.S
+6
-18
linux-user/host/i386/safe-syscall.inc.S
···
69
69
safe_syscall_start:
70
70
/* if signal_pending is non-zero, don't do the call */
71
71
mov 4+16(%esp), %eax /* signal_pending */
72
-
cmp $0, (%eax)
72
+
cmpl $0, (%eax)
73
73
jnz 1f
74
74
mov 8+16(%esp), %eax /* syscall number */
75
75
int $0x80
···
77
77
/* code path for having successfully executed the syscall */
78
78
pop %ebx
79
79
.cfi_remember_state
80
-
.cfi_def_cfa_offset -4
80
+
.cfi_adjust_cfa_offset -4
81
81
.cfi_restore ebx
82
82
pop %edi
83
-
.cfi_def_cfa_offset -4
83
+
.cfi_adjust_cfa_offset -4
84
84
.cfi_restore edi
85
85
pop %esi
86
-
.cfi_def_cfa_offset -4
86
+
.cfi_adjust_cfa_offset -4
87
87
.cfi_restore esi
88
88
pop %ebp
89
-
.cfi_def_cfa_offset -4
89
+
.cfi_adjust_cfa_offset -4
90
90
.cfi_restore ebp
91
91
ret
92
92
···
94
94
/* code path when we didn't execute the syscall */
95
95
.cfi_restore_state
96
96
mov $-TARGET_ERESTARTSYS, %eax
97
-
pop %ebx
98
-
.cfi_def_cfa_offset -4
99
-
.cfi_restore ebx
100
-
pop %edi
101
-
.cfi_def_cfa_offset -4
102
-
.cfi_restore edi
103
-
pop %esi
104
-
.cfi_def_cfa_offset -4
105
-
.cfi_restore esi
106
-
pop %ebp
107
-
.cfi_def_cfa_offset -4
108
-
.cfi_restore ebp
109
-
ret
97
+
jmp safe_syscall_end
110
98
.cfi_endproc
111
99
112
100
.size safe_syscall_base, .-safe_syscall_base