1. 18 10月, 2019 1 次提交
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      util: drop support for stack traces with logging · 9b80e0c1
      Daniel P. Berrangé 提交于
      The log filters have supported the use of a "+" before the source match
      string to request that a stack trace be emitted for every log message:
      
        commit 54856395
        Author: Daniel P. Berrange <berrange@redhat.com>
        Date:   Wed May 9 15:18:56 2012 +0100
      
          Allow stack traces to be included with log messages
      
          Sometimes it is useful to see the callpath for log messages.
          This change enhances the log filter syntax so that stack traces
          can be show by setting '1:+NAME' instead of '1:NAME'.
      
      With the huge & ever increasing number of logging statements per file,
      this will be incredibly verbose and have a major performance penalty.
      This makes the feature impractical to use widely and as such it is not
      worth the code maint cost.
      
      Removing this seldom used feature allows us to drop the 'execinfo'
      module in gnulib which provides the backtrace() function which doesn't
      exist on non-Linux.
      
      Users who want to get stack traces of parts of libvirt can use GDB,
      or systemtap for live tracing with minimal perf impact.
      Reviewed-by: NJán Tomko <jtomko@redhat.com>
      Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>
      9b80e0c1
  2. 15 10月, 2019 1 次提交
  3. 14 10月, 2019 1 次提交
  4. 07 5月, 2019 1 次提交
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      virtestmock: Initialize symbols from stat() and its friends · e1de5dd2
      Michal Privoznik 提交于
      Introduced by ff376c62.
      
      Previously, init_syms() was called from stat() mock and its
      friends. This is crucial because checkPath() might call
      printFile() which in turn calls real_fopen(). But if stat() or
      one of its friends is the first function called then because of
      lacking init_syms() call no real_* is initialized.
      
      The other thing is that we really want the recorded action to be
      "stat" instead of __FUNCTION__ because there's no good in
      recording that it was __xstat64 who touched some file.
      Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
      e1de5dd2
  5. 03 4月, 2019 1 次提交
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      tests: fix mocking of stat() / lstat() functions · ff376c62
      Daniel P. Berrangé 提交于
      Quite a few of the tests have a need to mock the stat() / lstat()
      functions and they are taking somewhat different & inconsistent
      approaches none of which are actually fully correct. This is shown
      by fact that 'make check' fails on 32-bit hosts. Investigation
      revealed that the code was calling into the native C library impl,
      not getting intercepted by our mocks.
      
      The POSIX stat() function might resolve to any number of different
      symbols in the C library.
      
      The may be an additional stat64() function exposed by the headers
      too.
      
      On 64-bit hosts the stat & stat64 functions are identical, always
      refering to the 64-bit ABI.
      
      On 32-bit hosts they refer to the 32-bit & 64-bit ABIs respectively.
      
      Libvirt uses _FILE_OFFSET_BITS=64 on 32-bit hosts, which causes the
      C library to transparently rewrite stat() calls to be stat64() calls.
      Libvirt will never see the 32-bit ABI from the traditional stat()
      call. We cannot assume this rewriting is done using a macro. It might
      be, but on GLibC it is done with a magic __asm__ statement to apply
      the rewrite at link time instead of at preprocessing.
      
      In GLibC there may be two additional functions exposed by the headers,
      __xstat() and __xstat64(). When these exist, stat() and stat64() are
      transparently rewritten to call __xstat() and __xstat64() respectively.
      The former symbols will not actally exist in the library at all, only
      the header. The leading "__" indicates the symbols are a private impl
      detail of the C library that applications should not care about.
      Unfortunately, because we are trying to mock replace the C library,
      we need to know about this internal impl detail.
      
      With all this in mind the list of functions we have to mock will depend
      on several factors
      
       - If _FILE_OFFSET_BITS is set, then we are on a 32-bit host, and we
         only need to mock stat64 and __xstat64. The other stat / __xstat
         functions exist, but we'll never call them so they can be ignored
         for mocking.
      
       - If _FILE_OFFSET_BITS is not set, then we are on a 64-bit host and
         we should mock stat, stat64, __xstat & __xstat64. Either may be
         called by app code.
      
       - If __xstat & __xstat64 exist, then stat & stat64 will not exist
         as symbols in the library, so the latter should not be mocked.
      
      The same all applies to lstat()
      
      These rules are complex enough that we don't want to duplicate them
      across every mock file, so this centralizes all the logic in a helper
      file virmockstathelper.c that should be #included when needed. The
      code merely need to provide a filename rewriting callback called
      virMockStatRedirect(). Optionally VIR_MOCK_STAT_HOOK can be defined
      as a macro if further processing is needed inline.
      Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>
      ff376c62
  6. 14 3月, 2019 1 次提交
  7. 14 12月, 2018 1 次提交
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      Remove all Author(s): lines from source file headers · 60046283
      Daniel P. Berrangé 提交于
      In many files there are header comments that contain an Author:
      statement, supposedly reflecting who originally wrote the code.
      In a large collaborative project like libvirt, any non-trivial
      file will have been modified by a large number of different
      contributors. IOW, the Author: comments are quickly out of date,
      omitting people who have made significant contribitions.
      
      In some places Author: lines have been added despite the person
      merely being responsible for creating the file by moving existing
      code out of another file. IOW, the Author: lines give an incorrect
      record of authorship.
      
      With this all in mind, the comments are useless as a means to identify
      who to talk to about code in a particular file. Contributors will always
      be better off using 'git log' and 'git blame' if they need to  find the
      author of a particular bit of code.
      
      This commit thus deletes all Author: comments from the source and adds
      a rule to prevent them reappearing.
      
      The Copyright headers are similarly misleading and inaccurate, however,
      we cannot delete these as they have legal meaning, despite being largely
      inaccurate. In addition only the copyright holder is permitted to change
      their respective copyright statement.
      Reviewed-by: NErik Skultety <eskultet@redhat.com>
      Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>
      60046283
  8. 05 12月, 2018 1 次提交
  9. 15 8月, 2018 1 次提交
    • M
      virtestmock: Track action · e3e48d7c
      Michal Privoznik 提交于
      As advertised in the previous commit, we need the list of
      accessed files to also contain action that caused the $path to
      appear on the list. Not only this enables us to fine tune our
      white list rules it also helps us to see why $path is reported.
      For instance:
      
        /run/user/1000/libvirt/libvirt-sock: connect: qemuxml2argvtest: QEMU XML-2-ARGV net-vhostuser-multiq
      Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
      Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
      e3e48d7c
  10. 27 7月, 2018 1 次提交
  11. 04 5月, 2018 2 次提交
  12. 20 5月, 2016 2 次提交
    • M
      virtestmock: Mock stat() properly · 49c1a078
      Michal Privoznik 提交于
      There is a lot to explain, but I try to make it as short as
      possible. I'd start by pasting some parts of sys/stat.h:
      
      extern int stat (const char *__restrict __file,
      		 struct stat *__restrict __buf) __THROW __nonnull ((1, 2));
      
      extern int __REDIRECT_NTH (stat, (const char *__restrict __file,
      				  struct stat *__restrict __buf), stat64)
           __nonnull ((1, 2));
      
      __extern_inline int
      __NTH (stat (const char *__path, struct stat *__statbuf))
      {
        return __xstat (_STAT_VER, __path, __statbuf);
      }
      
      Only one of these is effective at once, due to some usage of
      the mess we are dealing with in here. So, basically, while
      compiling or linking stat() in our code can be transformed into
      some other func. Or a dragon.
      Now, if you read stat(2) manpage, esp. "C library/kernel
      differences" section, you'll learn that glibc uses some tricks
      for older applications to work. I haven't gotten around actual
      code that does this, but based on my observations, if 'stat'
      symbol is found, glibc assumes it's dealing with ancient
      application. Unfortunately, it can be just ours stat coming from
      our mock. Therefore, calling stat() from a test will end up in
      our mock. But since glibc is not exposing the symbol anymore, our
      call of real_stat() will SIGSEGV immediately as the pointer to
      function is NULL. Therefore, we should expose only those symbols
      we know glibc has.
      Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
      49c1a078
    • M
      tests: Drop VIR_MOCK_CALL_STAT · 43639790
      Michal Privoznik 提交于
      It wasn't as great idea as I thought. Thing around stat() are
      more complicated than that. Therefore we need to revert
      86d1705a plus drop use of the macro as introduced in
      later patches.
      Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
      43639790
  13. 14 5月, 2016 2 次提交