Collect number of process FDs and /proc/self/limits (#90)

* Collect /proc/self/limits on Linux

* Keep config but commented out

* WIP: Use nix=0.26 to make mach build happy

* Fix build

* Fixup deny

* Bump stream count

---------

Co-authored-by: Alexandre Lissy <lissyx@lissyx.dyndns.org>
Co-authored-by: Jake Shadle <jake.shadle@embark-studios.com>

.cargo/config.toml

@@ -0,0 +1,11 @@
+# If you have a global config to use LLD on your machine, you might need to enable
+# this config to produce binaries that pass tests
+# [target.'cfg(all(target_os = "linux", target_arch = "x86_64"))']
+# rustflags = [
+#     "-C",
+#     "link-arg=-fuse-ld=lld",
+#     # LLD by default uses xxhash for build ids now, which breaks tests that assume
+#     # GUIDS or longer
+#     "-C",
+#     "link-arg=-Wl,--build-id=sha1",
+# ]

Cargo.toml

@@ -14,7 +14,7 @@ byteorder = "1.4"
 cfg-if = "1.0"
 crash-context = "0.6"
 memoffset = "0.9"
-minidump-common = "0.19"
+minidump-common = "0.19.1"
 scroll = "0.11"
 tempfile = "3.8"
 thiserror = "1.0"

src/linux/minidump_writer.rs

@@ -189,7 +189,7 @@ impl MinidumpWriter {
     ) -> Result<()> {
         // A minidump file contains a number of tagged streams. This is the number
         // of streams which we write.
-        let num_writers = 16u32;
+        let num_writers = 17u32;
 
         let mut header_section = MemoryWriter::<MDRawHeader>::alloc(buffer)?;
 
@@ -323,6 +323,17 @@ impl MinidumpWriter {
         // Write section to file
         dir_section.write_to_file(buffer, Some(dirent))?;
 
+        let dirent = match self.write_file(buffer, &format!("/proc/{}/limits", self.blamed_thread))
+        {
+            Ok(location) => MDRawDirectory {
+                stream_type: MDStreamType::MozLinuxLimits as u32,
+                location,
+            },
+            Err(_) => Default::default(),
+        };
+        // Write section to file
+        dir_section.write_to_file(buffer, Some(dirent))?;
+
         let dirent = thread_names_stream::write(buffer, dumper)?;
         // Write section to file
         dir_section.write_to_file(buffer, Some(dirent))?;

tests/linux_minidump_writer.rs

@@ -224,6 +224,9 @@ contextual_tests! {
         let _ = dump
             .get_raw_stream(LinuxDsoDebug as u32)
             .expect("Couldn't find LinuxDsoDebug");
+        let _ = dump
+            .get_raw_stream(MozLinuxLimits as u32)
+            .expect("Couldn't find MozLinuxLimits");
     }
 
     fn test_write_with_additional_memory(context: Context) {