Despite its name, libxl_xen_console_read_line() does not read a line,
it fills the buffer with as many characters as fit. Update the
documentation to reflect the real behaviour of the function. Rename
line_r to avoid confusion since it is a pointer to an array of
characters.
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
When reading the console, xen overwrites the contents of the buffer,
so there is no need to zero the buffer before passing it to xen.
Instead, add a NULL at the end of the buffer.
While we are at it, change the zalloc() of the buffer back to
malloc() as it was before bdf4131 (libxl: don't leak buf in
libxl_xen_console_read_start error handling, 2013-12-03). The comment
in that commit message says that the intent of the commit was to
change malloc+memset to zalloc(), but only for the
libxl_xen_console_reader struct, not for the buffer.
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
When built with ASAN, "xl dmesg" crashes in the "printf("%s", line)"
call in main_dmesg(). ASAN reports a heap buffer overflow: an
off-by-one access to cr->buffer.
The readconsole sysctl copies up to count characters into the buffer,
but it does not add a null character at the end. Despite the
documentation of libxl_xen_console_read_line(), line_r is not
nul-terminated if 16384 characters were copied to the buffer.
Fix this by asking xc_readconsolering() to fill the buffer up to size
- 1. As the number of characters in the buffer is only needed in
libxl_xen_console_read_line(), make it a local variable there instead
of part of the libxl__xen_console_reader struct.
Fixes: 4024bae739 ("xl: Add subcommand 'xl dmesg'")
Reported-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
If xenstored runs out of memory it is possible for it to fail operations
that should succeed. libxl wasn't robust against this, and could fail
to ensure that the TTY path of a non-initial console was created and
read-only for guests. This doesn't qualify for an XSA because guests
should not be able to run xenstored out of memory, but it still needs to
be fixed.
Add the missing error checks to ensure that all errors are properly
handled and that at no point can a guest make the TTY path of its
frontend directory writable.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Add -e argument to xl console and pass to new escape_character argument
of libxl_console_exec.
Introduce a new API version to support this new argument and advertise
the new functionality in libxl.h
In libxl_console_exec, there are currently two call sites to execl,
which uses varargs, in order to support optionally passing
'start-notify-fd' to the console client. In order to support passing
the 'escape' argument optionally too, refactor to instead have a single
call site to execv, which has the same behavior but takes an array of
arguments.
If -e is not specified, --escape is not passed to the console client and
the existing value (^]) is used as a default.
Update the xl docs.
Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Instead of duplicating libxl__device_console_add() work in
init-xenstore-domain.c, just use libxenlight.
This requires to add a small wrapper function to libxenlight, as
libxl__device_console_add() is an internal function.
This at once removes a theoretical race between starting xenconsoled
and xenstore-stubdom, as the old code wasn't using a single
transaction for writing all the entries, leading to the possibility
that xenconsoled would see only some of the entries being written.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The seemingly arbitrary use of 'pci' and 'pcidev' in the code in libxl_pci.c
is confusing and also compromises use of some macros used for other device
types. Indeed it seems that DEFINE_DEVICE_TYPE_STRUCT_X exists solely because
of this duality.
This patch purges use of 'pcidev' from the libxl internal code, but
unfortunately the 'pcidevs' and 'num_pcidevs' fields in 'libxl_domain_config'
are part of the API and need to be retained to avoid breaking callers,
particularly libvirt.
DEFINE_DEVICE_TYPE_STRUCT_X is still removed to avoid the special case in
libxl_pci.c but DEFINE_DEVICE_TYPE_STRUCT is given an extra 'array' argument
which is used to identify the fields in 'libxl_domain_config' relating to
the device type.
NOTE: Some of the more gross formatting errors (such as lack of spaces after
keywords) that came into context have been fixed in libxl_pci.c.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Carve out all libxenlight related sources and move them to
tools/libs/light in order to use the generic library build environment.
The closely related sources for libxl-save-helper and the libxl test
environment are being moved, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Javi Merino
Demi Marie Obenour
Peter Hoyes
Juergen Gross
Paul Durrant