[PATCH] D74154: LSAN for android

[Vy Nguyen via Phabricator via llvm-commits]

oontvoo marked an inline comment as done.
oontvoo added inline comments.


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Comment at: compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp:485
+                                   reinterpret_cast<void**>(&end_addr))){
+    fprintf(stderr, "Error getting TLS bounds\n");
+    *addr = 0;
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eugenis wrote:
> oontvoo wrote:
> > eugenis wrote:
> > > Printf
> > If the sanitizer crashes (which it does sometimes, mostly due to bugs) stuff going into printf() will not get printed - which makes it hard to debug.
> This code needs to be async signal safe, which fprintf is not. What kinds of bugs do you have in mind? Printf goes almost directly to stderr.
Ah, ok. I've switched the code to use write(), which should be signal safe. (http://man7.org/linux/man-pages/man7/signal.7.html)

When iterating on this patch, I had a few thinkos, causing sigsev and the log messages sent to printf were buffered and never got printed (I think they went to stdout, not stderr).
That's why I wanted to use stderr, which is not buffered.


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  https://reviews.llvm.org/D74154/new/

https://reviews.llvm.org/D74154