The convention is that
lzma_filter filters[LZMA_FILTERS_MAX + 1];
contains the filters of a single filter chain.
It was so here as well before the commit
d6af7f3470.
It changes "filters" to a ten-element array of filter chains.
It's clearer to call this array-of-arrays "chains".
This also renames "filter_idx" to "chain_idx" which is used
as an index as in chains[chain_idx].
opt_mode == MODE_COMPRESS isn't possible when HAVE_ENCODERS isn't
defined. Thus, when *encoding*, the message about *decoder* memory
usage is possible to show only when both encoder and decoder have
been built.
Since the message is shown only at V_DEBUG, skip the memusage
calculation if verbosity level isn't high enough.
Fixes: 5f0c5a0438
This was added to xz in 02e3505991
but I forgot to do the same in xzdec.
The Landlock sandbox in xzdec could be stricter as now it's
active only for the last file being decompressed. In xz,
read-only sandbox is used for multi-file case. On the other hand,
xz doesn't go to the strictest mode when processing the last file
when more than one file was specified; xzdec does.
Clang 17 with -fsanitize=address,undefined:
src/liblzma/common/filter_common.c:366:8: runtime error:
call to function encoder_find through pointer to incorrect
function type 'const lzma_filter_coder *(*)(unsigned long)'
src/liblzma/common/filter_encoder.c:187: note:
encoder_find defined here
Use a wrapper function to get the correct type neatly.
This reduces the number of casts needed too.
This issue could be a problem with control flow integrity (CFI)
methods that check the function type on indirect function calls.
Fixes: 3b34851de1
It's undefined behavior. The result wasn't ever used as it occurred
in the last iteration of a loop.
Clang 17 with -fsanitize=address,undefined:
$ src/xz/xz --block-list=123
src/xz/args.c:164:12: runtime error: applying non-zero offset 1
to null pointer
Fixes: 88ccf47205
Co-authored-by: Sam James <sam@gentoo.org>
If the arguments to lzma_index_decoder() or lzma_index_buffer_decode()
were such that LZMA_PROG_ERROR was returned, the lzma_index **i
argument wasn't touched even though the API docs say that *i = NULL
is done if an error occurs. This obviously won't be done even now
if i == NULL but otherwise it is best to do it due to the wording
in the API docs.
In practice this matters very little: The problem can occur only
if the functions are called with invalid arguments, that is,
the calling application must already have a bug.
The __builtin_bswapXX from GCC and Clang are preferred when
they are available. This can allow compilers to emit the x86 MOVBE
instruction instead of doing a load + byteswap as two instructions
(which would happen if the byteswapping is done in inline asm).
bswap16, bswap32, and bswap64 exist in system headers on *BSDs
and Darwin. #defining bswap16 on NetBSD results in a warning about
macro redefinition. It's safest to avoid this namespace conflict
completely.
No OS supported by tuklib_integer.h uses byteswapXX names and
a web search doesn't immediately find any obvious danger of
namespace conflicts. So let's try these still-pretty-short names
for the macros.
Thanks to Sam James for pointing out the compiler warning on
NetBSD 10.0.
The API docs clearly say that if error_pos isn't NULL then *error
is always set on any error. However, it wasn't touched if str == NULL
or filters == NULL or unsupported flags were specified.
Fixes: cedeeca2ea
It is logical why it cannot know for sure that the value has
to be at most 4 if it is less than 16.
The x86 filter is based on a very old LZMA SDK version. Newer
ones have quite a different implementation for the same filter.
Thanks to Sam James.
On macOS, we get:
```
signals.c: In function 'signals_init':
signals.c:76:17: error: conversion to 'sigset_t' {aka 'unsigned int'} from 'int' may change the sign of the result [-Werror=sign-conversion]
76 | sigaddset(&hooked_signals, sigs[i]);
| ^~~~~~~~~
signals.c:81:17: error: conversion to 'sigset_t' {aka 'unsigned int'} from 'int' may change the sign of the result [-Werror=sign-conversion]
81 | sigaddset(&hooked_signals, message_progress_sigs[i]);
| ^~~~~~~~~
signals.c:86:9: error: conversion to 'sigset_t' {aka 'unsigned int'} from 'int' may change the sign of the result [-Werror=sign-conversion]
86 | sigaddset(&hooked_signals, SIGTSTP);
| ^~~~~~~~~
```
We use `int` for `hooked_signals` but we can't just cast to whatever
`sigset_t` is because `sigset_t` is an opaque type. It's an unsigned int
on macOS. On macOS, `sigaddset` is implemented as a macro.
Just suppress -Wsign-conversion for `signals_init` for macOS given
there's no real nice way of fixing this.
This is *NOT* done for security reasons even though the backdoor
relied on the ifunc code. Instead, the reason is that in this
project ifunc provides little benefits but it's quite a bit of
extra code to support it. The only case where ifunc *might* matter
for performance is if the CRC functions are used directly by an
application. In normal compression use it's completely irrelevant.
Lasse Collin
Sam James