8f17282...
by
Kienan Stewart <email address hidden>
docs: Correct GitHub URLs in lttng-ust.3
The branches follow the format `stable-X.YZ` rather than `vX.YZ`.
Furthermore, when rendering the man pages from source, the URLs were
omitted completely as the subsitution `{lttng_version}` was not
defined. This hasn't been an issue for the published HTML versions as
those are produced via a different script in the `lttng-www` project
which presumably sets the substitution properly.
fix: handle EINTR correctly in get_cpu_mask_from_sysfs
If the read() in get_cpu_mask_from_sysfs() fails with EINTR, the code is
supposed to retry, but the while loop condition has (bytes_read > 0),
which is false when read() fails with EINTR. The result is that the code
exits the loop, having only read part of the string.
Use (bytes_read != 0) in the while loop condition instead, since the
(bytes_read < 0) case is already handled in the loop.
Original fix in liburcu from Benjamin Marzinski <email address hidden>:
commit 9922f33e2986 ("fix: handle EINTR correctly in get_cpu_mask_from_sysfs")
glibc 2.34 implements close_range(2), which is used by the ssh client
(amongst others). This needs to be overridden to make sure ssh does not
close lttng-ust file descriptors.
`len_type' of a sequence field must be of type unsigned integer. Some
provided examples in the man page were incorrectly using a type signed
integer, resulting in correct compilation, but error while decoding.
Fix: libc wrapper: use initial-exec for malloc_nesting TLS
Use the initial-exec TLS model for the malloc_nesting nesting guard
variable to ensure that the glibc implementation of the TLS access don't
trigger infinite recursion by calling the memory allocator wrapper
functions, which can happen with global-dynamic.
Considering that the libc wrapper is meant to be loaded with LD_PRELOAD
anyway (never with dlopen(3)), we always expect the libc to have enough
space to hold the malloc_nesting variable.
In addition to change the malloc_nesting from global-dynamic to
initial-exec, this removes the URCU TLS compatibility layer from the
libc wrapper, which is a good thing: this compatibility layer relies
on pthread key and calloc internally, which makes it a bad fit for TLS
accesses guarding access to malloc wrappers, due to possible infinite
recursion.
