From f606e4d6258fa82c3f6c1cc762ebe483db5f5db6 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Thu, 10 May 2018 22:59:49 +0200 Subject: [PATCH] linux-user: correctly align types in thunking code This is a follow up of patch: commit c2e3dee6e03527baf8698698cce76b1a3174969a Author: Laurent Vivier Date: Sun Feb 13 23:37:34 2011 +0100 linux-user: Define target alignment size In my case m68k aligns "int" on 2 not 4. You can check this with the following program: int main(void) { struct rtentry rt; printf("rt_pad1 %ld %zd\n", offsetof(struct rtentry, rt_pad1), sizeof(rt.rt_pad1)); printf("rt_dst %ld %zd\n", offsetof(struct rtentry, rt_dst), sizeof(rt.rt_dst)); printf("rt_gateway %ld %zd\n", offsetof(struct rtentry, rt_gateway), sizeof(rt.rt_gateway)); printf("rt_genmask %ld %zd\n", offsetof(struct rtentry, rt_genmask), sizeof(rt.rt_genmask)); printf("rt_flags %ld %zd\n", offsetof(struct rtentry, rt_flags), sizeof(rt.rt_flags)); printf("rt_pad2 %ld %zd\n", offsetof(struct rtentry, rt_pad2), sizeof(rt.rt_pad2)); printf("rt_pad3 %ld %zd\n", offsetof(struct rtentry, rt_pad3), sizeof(rt.rt_pad3)); printf("rt_pad4 %ld %zd\n", offsetof(struct rtentry, rt_pad4), sizeof(rt.rt_pad4)); printf("rt_metric %ld %zd\n", offsetof(struct rtentry, rt_metric), sizeof(rt.rt_metric)); printf("rt_dev %ld %zd\n", offsetof(struct rtentry, rt_dev), sizeof(rt.rt_dev)); printf("rt_mtu %ld %zd\n", offsetof(struct rtentry, rt_mtu), sizeof(rt.rt_mtu)); printf("rt_window %ld %zd\n", offsetof(struct rtentry, rt_window), sizeof(rt.rt_window)); printf("rt_irtt %ld %zd\n", offsetof(struct rtentry, rt_irtt), sizeof(rt.rt_irtt)); } And result is : i386 rt_pad1 0 4 rt_dst 4 16 rt_gateway 20 16 rt_genmask 36 16 rt_flags 52 2 rt_pad2 54 2 rt_pad3 56 4 rt_pad4 62 2 rt_metric 64 2 rt_dev 68 4 rt_mtu 72 4 rt_window 76 4 rt_irtt 80 2 m68k rt_pad1 0 4 rt_dst 4 16 rt_gateway 20 16 rt_genmask 36 16 rt_flags 52 2 rt_pad2 54 2 rt_pad3 56 4 rt_pad4 62 2 rt_metric 64 2 rt_dev 66 4 rt_mtu 70 4 rt_window 74 4 rt_irtt 78 2 This affects the "route" command : WITHOUT this patch: $ sudo route add -net default gw 10.0.3.1 window 1024 irtt 2 eth0 $ netstat -nr Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 10.0.3.1 0.0.0.0 UG 0 67108866 32768 eth0 10.0.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 WITH this patch: $ sudo route add -net default gw 10.0.3.1 window 1024 irtt 2 eth0 $ netstat -nr Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 10.0.3.1 0.0.0.0 UG 0 1024 2 eth0 10.0.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 Signed-off-by: Laurent Vivier Reviewed-by: Peter Maydell Message-Id: <20180510205949.26455-1-laurent@vivier.eu> --- include/exec/user/thunk.h | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/include/exec/user/thunk.h b/include/exec/user/thunk.h index f19ef4b230..8f55b233b3 100644 --- a/include/exec/user/thunk.h +++ b/include/exec/user/thunk.h @@ -149,20 +149,32 @@ static inline int thunk_type_align(const argtype *type_ptr, int is_host) case TYPE_CHAR: return 1; case TYPE_SHORT: - return 2; + if (is_host) { + return __alignof__(short); + } else { + return ABI_SHORT_ALIGNMENT; + } case TYPE_INT: - return 4; + if (is_host) { + return __alignof__(int); + } else { + return ABI_INT_ALIGNMENT; + } case TYPE_LONGLONG: case TYPE_ULONGLONG: - return 8; + if (is_host) { + return __alignof__(long long); + } else { + return ABI_LLONG_ALIGNMENT; + } case TYPE_LONG: case TYPE_ULONG: case TYPE_PTRVOID: case TYPE_PTR: if (is_host) { - return sizeof(void *); + return __alignof__(long); } else { - return TARGET_ABI_BITS / 8; + return ABI_LONG_ALIGNMENT; } break; case TYPE_OLDDEVT: