Stream: git-wasmtime

Topic: wasmtime / Issue #2009 Opening files with O_TRUNC does no...

Wasmtime GitHub notifications bot (Jul 10 2020 at 14:52):

whitequark opened Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Wasmtime GitHub notifications bot (Jul 10 2020 at 14:52):

whitequark labeled Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Wasmtime GitHub notifications bot (Jul 10 2020 at 14:52):

whitequark edited Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Wasmtime GitHub notifications bot (Jul 10 2020 at 14:54):

whitequark commented on Issue #2009:

Here's the WASI call log:

 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(0)
 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(1)
 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(2)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(3)
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (0, Some(PendingEntry::Thunk(0x32d058)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (1, Some(PendingEntry::Thunk(0x32d068)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (2, Some(PendingEntry::Thunk(0x32d078)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (3, Entry { file_type: 3, descriptor: OsHandle(OsHandle(File { handle: 0x5c, path: "\\\\?\\Z:\\home\\whitequark\\xxx\\build" })), rights_base: 264240858, rights_inheriting: 268435455, preopen_path: Some(".") })
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx entries = {0: Entry { file_type: 2, descriptor: Stdin, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }, 3: Entry { file_type: 3, descriptor: OsHandle(OsHandle(File { handle: 0x5c, path: "\\\\?\\Z:\\home\\whitequark\\xxx\\build" })), rights_base: 264240858, rights_inheriting: 268435455, preopen_path: Some(".") }, 1: Entry { file_type: 2, descriptor: Stdout, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }, 2: Entry { file_type: 2, descriptor: Stderr, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }}
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > fd=Fd(3)
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > buf=Dir(PrestatDir { pr_name_len: 1 })
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_dir_name"
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > fd=Fd(3) path=*guest 0x20010 path_len=1
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | path='.'
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > error=Badf
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_fdstat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(3)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > stat=Fdstat { fs_filetype: Directory, fs_flags: Fdflags(0), fs_rights_base: Rights(264240858), fs_rights_inheriting: Rights(268435455) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="path_open"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(3) dirflags=symlink_follow (0x1) path=*guest 0x400/8 oflags=creat|trunc (0x9) fs_rights_base=fd_datasync|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffbffd) fs_rights_inherting=fd_datasync|fd_read|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|fd_readdir|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffffff) fdflags=empty (0x0)
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | needed_rights=HandleRights { base: path_create_file|path_open (0x2400), inheriting: fd_datasync|fd_read|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|fd_readdir|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffffff) }
 TRACE wasi_common::path                              >      | (path_ptr,path_len)='test.txt'
 DEBUG wasi_common::path                              > path_get cur_path = "test.txt"
 DEBUG wasi_common::path                              > path_get path_stack = []
 DEBUG wasi_common::sys::windows::path                > out_path="Z:\\home\\whitequark\\xxx\\build\\test.txt"
 DEBUG wasi_common::sys::windows::path                > readlinkat error=50
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | calling path_open impl: read=false, write=true
 DEBUG wasi_common::sys::windows::path                > out_path="Z:\\home\\whitequark\\xxx\\build\\test.txt"
 DEBUG wasi_common::sys                               > Created new instance of OsFile: OsFile { rights: Cell { value: HandleRights { base: Rights(148898303), inheriting: Rights(0) } }, handle: RawOsHandle(Cell { value: 0x64 }) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > opened_fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_fdstat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > stat=Fdstat { fs_filetype: RegularFile, fs_flags: Fdflags(0), fs_rights_base: Rights(148898301), fs_rights_inheriting: Rights(0) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_write"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4) iovs=*guest 0x150b0/2
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > nwritten=16
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_close"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))

Wasmtime GitHub notifications bot (Jul 10 2020 at 14:55):

whitequark edited a comment on Issue #2009:

Here's the WASI call log (this is on wine, but I'm triaging a bug report from someone who hits it on Windows):

 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(0)
 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(1)
 DEBUG wasi_common::ctx > WasiCtx inserting entry PendingEntry::Thunk(0x32cde8)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(2)
 DEBUG wasi_common::ctx > WasiCtx inserted at Fd(3)
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (0, Some(PendingEntry::Thunk(0x32d058)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (1, Some(PendingEntry::Thunk(0x32d068)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (2, Some(PendingEntry::Thunk(0x32d078)))
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx inserting (3, Entry { file_type: 3, descriptor: OsHandle(OsHandle(File { handle: 0x5c, path: "\\\\?\\Z:\\home\\whitequark\\xxx\\build" })), rights_base: 264240858, rights_inheriting: 268435455, preopen_path: Some(".") })
 DEBUG wasi_common::old::snapshot_0::ctx > WasiCtx entries = {0: Entry { file_type: 2, descriptor: Stdin, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }, 3: Entry { file_type: 3, descriptor: OsHandle(OsHandle(File { handle: 0x5c, path: "\\\\?\\Z:\\home\\whitequark\\xxx\\build" })), rights_base: 264240858, rights_inheriting: 268435455, preopen_path: Some(".") }, 1: Entry { file_type: 2, descriptor: Stdout, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }, 2: Entry { file_type: 2, descriptor: Stderr, rights_base: 136314954, rights_inheriting: 136314954, preopen_path: None }}
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > fd=Fd(3)
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > buf=Dir(PrestatDir { pr_name_len: 1 })
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_dir_name"
 TRACE wasi_common::wasi::wasi_snapshot_preview1 > fd=Fd(3) path=*guest 0x20010 path_len=1
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | path='.'
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_prestat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > error=Badf
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_fdstat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(3)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > stat=Fdstat { fs_filetype: Directory, fs_flags: Fdflags(0), fs_rights_base: Rights(264240858), fs_rights_inheriting: Rights(268435455) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="path_open"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(3) dirflags=symlink_follow (0x1) path=*guest 0x400/8 oflags=creat|trunc (0x9) fs_rights_base=fd_datasync|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffbffd) fs_rights_inherting=fd_datasync|fd_read|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|fd_readdir|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffffff) fdflags=empty (0x0)
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | needed_rights=HandleRights { base: path_create_file|path_open (0x2400), inheriting: fd_datasync|fd_read|fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_write|fd_advise|fd_allocate|path_create_directory|path_create_file|path_link_source|path_link_target|path_open|fd_readdir|path_readlink|path_rename_source|path_rename_target|path_filestat_get|path_filestat_set_size|path_filestat_set_times|fd_filestat_get|fd_filestat_set_size|fd_filestat_set_times|path_symlink|path_remove_directory|path_unlink_file|poll_fd_readwrite (0xfffffff) }
 TRACE wasi_common::path                              >      | (path_ptr,path_len)='test.txt'
 DEBUG wasi_common::path                              > path_get cur_path = "test.txt"
 DEBUG wasi_common::path                              > path_get path_stack = []
 DEBUG wasi_common::sys::windows::path                > out_path="Z:\\home\\whitequark\\xxx\\build\\test.txt"
 DEBUG wasi_common::sys::windows::path                > readlinkat error=50
 TRACE wasi_common::snapshots::wasi_snapshot_preview1 >      | calling path_open impl: read=false, write=true
 DEBUG wasi_common::sys::windows::path                > out_path="Z:\\home\\whitequark\\xxx\\build\\test.txt"
 DEBUG wasi_common::sys                               > Created new instance of OsFile: OsFile { rights: Cell { value: HandleRights { base: Rights(148898303), inheriting: Rights(0) } }, handle: RawOsHandle(Cell { value: 0x64 }) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > opened_fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_fdstat_get"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > stat=Fdstat { fs_filetype: RegularFile, fs_flags: Fdflags(0), fs_rights_base: Rights(148898301), fs_rights_inheriting: Rights(0) }
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_write"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4) iovs=*guest 0x150b0/2
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > nwritten=16
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > wiggle abi; module="wasi_snapshot_preview1" function="fd_close"
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > fd=Fd(4)
 TRACE wasi_common::wasi::wasi_snapshot_preview1      > success=No error occurred. System call completed successfully. (Errno::Success(0))

Wasmtime GitHub notifications bot (Jul 10 2020 at 18:47):

peterhuene commented on Issue #2009:

An oflag of CREAT | TRUNC should result in a creation disposition flag of CREATE_ALWAYS. That would normally be truncating the file if we were using the Windows API directly.

However, I think the problem lies here where we're converting the Windows disposition flag to a Rust OpenOptions. That should probably have a truncate(true) on it.

Wasmtime GitHub notifications bot (Jul 10 2020 at 18:50):

peterhuene labeled Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Wasmtime GitHub notifications bot (Jul 10 2020 at 18:50):

peterhuene labeled Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Wasmtime GitHub notifications bot (Jul 10 2020 at 18:51):

github-actions[bot] commented on Issue #2009:

Subscribe to Label Action

cc @kubkon

<details>
This issue or pull request has been labeled: "wasi"

Thus the following users have been cc'd because of the following labels:

• kubkon: wasi

To subscribe or unsubscribe from this label, edit the <code>.github/subscribe-to-label.json</code> configuration file.

Learn more.
</details>

Wasmtime GitHub notifications bot (Jul 10 2020 at 19:15):

whitequark commented on Issue #2009:

However, I think the problem lies here where we're converting the Windows disposition flag to a Rust OpenOptions. That should probably have a truncate(true) on it.

Nope, that code doesn't even run (I put a panic in it).

Wasmtime GitHub notifications bot (Jul 10 2020 at 19:21):

whitequark commented on Issue #2009:

Sorry, I forgot a --dir . and the application silently crashed (because -fno-exceptions...). I can confirm that this fixes the bug.

Wasmtime GitHub notifications bot (Jul 12 2020 at 00:11):

peterhuene closed Issue #2009:

Consider the following program:

#include <fstream>

int main() {
    std::ofstream ff;
    ff.open("test.txt", std::ofstream::trunc);
    ff << "bad bad bad bad\n";
    return 0;
}

I've attached it here: bad.zip

Open test.txt and put something like this there:

bad bad bad bad
this will remain here

Run it:

wasmtime run --dir . bad.wasm

The file is not truncated.

Last updated: Oct 23 2024 at 20:03 UTC