[01/11] linux-user: fix statfs

Submitted by riku.voipio@linaro.org on Oct. 18, 2012, 11:30 a.m.

Details

Message ID 229d3376a38bf97aa09b6f73a957c5389badcd06.1350559608.git.riku.voipio@linaro.org
State New
Headers show

Commit Message

riku.voipio@linaro.org Oct. 18, 2012, 11:30 a.m.
From: Alexander Graf <agraf@suse.de>

The statfs syscall should always memset(0) its full struct extent before
writing to it. Newer versions of the syscall use one of the reserved fields
for flags, which would otherwise get stale values from uncleaned memory.

This fixes libarchive for me, which got confused about the return value of
pathconf("/", _PC_REC_XFER_ALIGN) otherwise, as it some times gave old pointers
as return value.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 linux-user/syscall.c |    4 ++++
 1 file changed, 4 insertions(+)

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diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 471d060..1a38169 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6529,6 +6529,8 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]);
             __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]);
             __put_user(stfs.f_namelen, &target_stfs->f_namelen);
+            __put_user(stfs.f_frsize, &target_stfs->f_frsize);
+            memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare));
             unlock_user_struct(target_stfs, arg2, 1);
         }
         break;
@@ -6557,6 +6559,8 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]);
             __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]);
             __put_user(stfs.f_namelen, &target_stfs->f_namelen);
+            __put_user(stfs.f_frsize, &target_stfs->f_frsize);
+            memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare));
             unlock_user_struct(target_stfs, arg3, 1);
         }
         break;