chromiumOSPackages.sommelier: fix log spam

Previously, sommelier would output many lines per second saying:

> Failed to send message to virtwl: Success

This made it extremely annoying to use the serial console, and
very difficult to see other log output.

This was happening because Sommelier's check for the return value of
the VIRTWL_IOCTL_SEND ioctl was inverted from what it should be.
That is, the failure message was printed only on success.  If there
actually was an error, no error message would be outputted.

The upstream patch I've added here is a bit vague that this was the
problem, but it does fix the issue.

8 files changed, 258 insertions, 12 deletions

diff --git a/pkgs/os-specific/linux/chromium-os/common-mk/0001-common-mk-don-t-leak-source-absolute-paths.patch b/pkgs/os-specific/linux/chromium-os/common-mk/0001-common-mk-don-t-leak-source-absolute-paths.patch
index 741b50af1b4..eb79e1ae8fa 100644
--- a/pkgs/os-specific/linux/chromium-os/common-mk/0001-common-mk-don-t-leak-source-absolute-paths.patch
+++ b/pkgs/os-specific/linux/chromium-os/common-mk/0001-common-mk-don-t-leak-source-absolute-paths.patch
@@ -1,7 +1,7 @@
 From 56d3fe9520c1ef2a6400939f4deae06d9b5cdfc2 Mon Sep 17 00:00:00 2001
 From: Alyssa Ross <hi@alyssa.is>
 Date: Sun, 24 Nov 2019 16:56:11 +0000
-Subject: [PATCH 1/6] common-mk: don't leak source-absolute paths
+Subject: [PATCH 1/7] common-mk: don't leak source-absolute paths
 
 Source-absolute paths like //vm_tools/whatever were being leaked to
 subprocesses, which of course didn't know how to understand them.
@@ -135,5 +135,5 @@ index 7fcb08341..692704288 100644
    }
  }
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/common-mk/0002-common-mk-.gn-don-t-hardcode-env-path.patch b/pkgs/os-specific/linux/chromium-os/common-mk/0002-common-mk-.gn-don-t-hardcode-env-path.patch
index 51c15dcd4cb..9d4843064d2 100644
--- a/pkgs/os-specific/linux/chromium-os/common-mk/0002-common-mk-.gn-don-t-hardcode-env-path.patch
+++ b/pkgs/os-specific/linux/chromium-os/common-mk/0002-common-mk-.gn-don-t-hardcode-env-path.patch
@@ -1,7 +1,7 @@
 From ec1afec90fd8e391b93f53f0abd8bc11cdba0a32 Mon Sep 17 00:00:00 2001
 From: Alyssa Ross <hi@alyssa.is>
 Date: Sun, 24 Nov 2019 17:20:46 +0000
-Subject: [PATCH 2/6] common-mk: .gn: don't hardcode env path
+Subject: [PATCH 2/7] common-mk: .gn: don't hardcode env path
 
 This is needlessly non-portable.
 ---
@@ -19,5 +19,5 @@ index e7dba8c91..e29fcd61e 100644
 -script_executable = "/usr/bin/env"
 +script_executable = "env"
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/common-mk/0003-Revert-common-mk-Suppress-Wrange-loop-analysis-warni.patch b/pkgs/os-specific/linux/chromium-os/common-mk/0003-Revert-common-mk-Suppress-Wrange-loop-analysis-warni.patch
index d3d4e915163..f64969fc811 100644
--- a/pkgs/os-specific/linux/chromium-os/common-mk/0003-Revert-common-mk-Suppress-Wrange-loop-analysis-warni.patch
+++ b/pkgs/os-specific/linux/chromium-os/common-mk/0003-Revert-common-mk-Suppress-Wrange-loop-analysis-warni.patch
@@ -1,7 +1,7 @@
 From b3add805d98e01488d71cbad51206f3a4949bb1c Mon Sep 17 00:00:00 2001
 From: Denis Nikitin <denik@chromium.org>
 Date: Wed, 5 Feb 2020 18:43:38 +0000
-Subject: [PATCH 3/6] Revert "common-mk: Suppress -Wrange-loop-analysis
+Subject: [PATCH 3/7] Revert "common-mk: Suppress -Wrange-loop-analysis
  warning"
 
 This reverts commit 09298dce8d31b5744a83784d027a3fd1e312eb6d.
@@ -68,5 +68,5 @@ index 7c0601b18..dc02a6979 100644
    cflags_c = [ "-std=gnu11" ] + external_cppflags + external_cxxflags
    cflags_cc = [ "-std=gnu++14" ] + external_cppflags + external_cxxflags
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/sommelier/0004-sommelier-don-t-leak-source-absolute-paths.patch b/pkgs/os-specific/linux/chromium-os/sommelier/0004-sommelier-don-t-leak-source-absolute-paths.patch
index 756584365c7..5d3ec4effe8 100644
--- a/pkgs/os-specific/linux/chromium-os/sommelier/0004-sommelier-don-t-leak-source-absolute-paths.patch
+++ b/pkgs/os-specific/linux/chromium-os/sommelier/0004-sommelier-don-t-leak-source-absolute-paths.patch
@@ -1,7 +1,7 @@
 From 1fa4de5b2228c40b25fd6333a74ae7535d73bcce Mon Sep 17 00:00:00 2001
 From: Alyssa Ross <hi@alyssa.is>
 Date: Sun, 1 Dec 2019 17:04:04 +0000
-Subject: [PATCH 4/6] sommelier: don't leak source-absolute paths
+Subject: [PATCH 4/7] sommelier: don't leak source-absolute paths
 
 ---
  vm_tools/sommelier/wayland_protocol.gni | 2 +-
@@ -21,5 +21,5 @@ index 4f18a0c10..b1bd5d659 100644
      }
    }
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/sommelier/0005-sommelier-use-stable-xdg-shell-protocol.patch b/pkgs/os-specific/linux/chromium-os/sommelier/0005-sommelier-use-stable-xdg-shell-protocol.patch
index 20994bc1785..5a6e57375a3 100644
--- a/pkgs/os-specific/linux/chromium-os/sommelier/0005-sommelier-use-stable-xdg-shell-protocol.patch
+++ b/pkgs/os-specific/linux/chromium-os/sommelier/0005-sommelier-use-stable-xdg-shell-protocol.patch
@@ -1,7 +1,7 @@
 From 5068e64b2fdedca0a4a9f1894335af8587c4c55a Mon Sep 17 00:00:00 2001
 From: Puck Meerburg <puck@puckipedia.com>
 Date: Tue, 3 Dec 2019 18:06:14 +0000
-Subject: [PATCH 5/6] sommelier: use stable xdg-shell protocol
+Subject: [PATCH 5/7] sommelier: use stable xdg-shell protocol
 
 From https://github.com/wayland-project/weston/commit/d8d9f5e6e16c8f6a3c06763d5f56c27dc9a6e52e:
 
@@ -1744,5 +1744,5 @@ index b851b5c8d..7e6daf773 100644
  struct sl_global* sl_gtk_shell_global_create(struct sl_context* ctx);
  
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/sommelier/0006-sommelier-make-building-demos-optional.patch b/pkgs/os-specific/linux/chromium-os/sommelier/0006-sommelier-make-building-demos-optional.patch
index 277ffa47ce7..3538932d804 100644
--- a/pkgs/os-specific/linux/chromium-os/sommelier/0006-sommelier-make-building-demos-optional.patch
+++ b/pkgs/os-specific/linux/chromium-os/sommelier/0006-sommelier-make-building-demos-optional.patch
@@ -1,7 +1,7 @@
 From 8774d76f1b57092df9004d654fd075d7691b9f12 Mon Sep 17 00:00:00 2001
 From: Alyssa Ross <hi@alyssa.is>
 Date: Wed, 15 Jan 2020 21:36:43 +0000
-Subject: [PATCH 6/6] sommelier: make building demos optional
+Subject: [PATCH 6/7] sommelier: make building demos optional
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
@@ -96,5 +96,5 @@ index 4330560a1..cbb752745 100644
 +  }
  }
 -- 
-2.25.1
+2.26.2
 
diff --git a/pkgs/os-specific/linux/chromium-os/sommelier/0007-vm_tools-sommelier-Log-the-value-of-strerror-when-as.patch b/pkgs/os-specific/linux/chromium-os/sommelier/0007-vm_tools-sommelier-Log-the-value-of-strerror-when-as.patch
new file mode 100644
index 00000000000..778c481d598
--- /dev/null
+++ b/pkgs/os-specific/linux/chromium-os/sommelier/0007-vm_tools-sommelier-Log-the-value-of-strerror-when-as.patch
@@ -0,0 +1,245 @@
+From 64afc7e7271e0bad332a8a246a4fb4151b3d296f Mon Sep 17 00:00:00 2001
+From: Fergus Dall <sidereal@google.com>
+Date: Fri, 27 Mar 2020 18:34:04 +1100
+Subject: [PATCH 7/7] vm_tools: sommelier: Log the value of strerror when
+ asserting
+
+There's some reports of sommelier crashing with assert failures, and
+right now we don't even have a way to tell what the error was from the
+logs.
+
+BUG=chromium:1053843
+TEST=emerge-tatl vm_guest_tools
+
+Change-Id: Iac9e0470600f7c7a8d8328049a79305251d7ef7f
+Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2124131
+Commit-Queue: Fergus Dall <sidereal@google.com>
+Tested-by: Fergus Dall <sidereal@google.com>
+Reviewed-by: Nic Hollingum <hollingum@google.com>
+---
+ vm_tools/sommelier/sommelier.c | 65 +++++++++++++++++-----------------
+ 1 file changed, 32 insertions(+), 33 deletions(-)
+
+diff --git a/vm_tools/sommelier/sommelier.c b/vm_tools/sommelier/sommelier.c
+index 5e03d8978..ffe6f645c 100644
+--- a/vm_tools/sommelier/sommelier.c
++++ b/vm_tools/sommelier/sommelier.c
+@@ -37,6 +37,15 @@
+ #include "viewporter-client-protocol.h"
+ #include "xdg-shell-client-protocol.h"
+ 
++#define errno_assert(rv)                                          \
++  {                                                               \
++    int macro_private_assert_value = (rv);                        \
++    if (!macro_private_assert_value) {                            \
++      fprintf(stderr, "Unexpected error: %s\n", strerror(errno)); \
++      assert(false);                                              \
++    }                                                             \
++  }
++
+ // Check that required macro definitions exist.
+ #ifndef XWAYLAND_PATH
+ #error XWAYLAND_PATH must be defined
+@@ -239,7 +248,7 @@ struct sl_mmap* sl_mmap_create(int fd,
+   map->buffer_resource = NULL;
+   map->addr =
+       mmap(NULL, size + offset0, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+-  assert(map->addr != MAP_FAILED);
++  errno_assert(map->addr != MAP_FAILED);
+ 
+   return map;
+ }
+@@ -2183,8 +2192,7 @@ int sl_begin_data_source_send(struct sl_context* ctx,
+ 
+   flags = fcntl(fd, F_GETFL, 0);
+   rv = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+-  assert(!rv);
+-  UNUSED(rv);
++  errno_assert(!rv);
+ 
+   ctx->selection_data_source_send_fd = fd;
+   free(reply);
+@@ -2810,7 +2818,7 @@ static void sl_send_data(struct sl_context* ctx, xcb_atom_t data_type) {
+       int p[2];
+ 
+       rv = pipe2(p, O_CLOEXEC | O_NONBLOCK);
+-      assert(!rv);
++      errno_assert(!rv);
+ 
+       fd_to_receive = p[0];
+       fd_to_wayland = p[1];
+@@ -3153,7 +3161,7 @@ static void sl_sd_notify(const char* state) {
+   assert(socket_name);
+ 
+   fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+-  assert(fd >= 0);
++  errno_assert(fd >= 0);
+ 
+   memset(&addr, 0, sizeof(addr));
+   addr.sun_family = AF_UNIX;
+@@ -3171,8 +3179,7 @@ static void sl_sd_notify(const char* state) {
+   msghdr.msg_iovlen = 1;
+ 
+   rv = sendmsg(fd, &msghdr, MSG_NOSIGNAL);
+-  assert(rv != -1);
+-  UNUSED(rv);
++  errno_assert(rv != -1);
+ }
+ 
+ static int sl_handle_sigchld(int signal_number, void* data) {
+@@ -3304,7 +3311,7 @@ static int sl_handle_display_ready_event(int fd, uint32_t mask, void* data) {
+                       (int)(XCURSOR_SIZE_BASE * ctx->scale + 0.5)));
+ 
+   pid = fork();
+-  assert(pid >= 0);
++  errno_assert(pid >= 0);
+   if (pid == 0) {
+     sl_execvp(ctx->runprog[0], ctx->runprog, -1);
+     _exit(EXIT_FAILURE);
+@@ -3373,8 +3380,7 @@ static int sl_handle_virtwl_ctx_event(int fd, uint32_t mask, void* data) {
+   }
+ 
+   bytes = sendmsg(ctx->virtwl_socket_fd, &msg, MSG_NOSIGNAL);
+-  assert(bytes == ioctl_recv->len);
+-  UNUSED(bytes);
++  errno_assert(bytes == ioctl_recv->len);
+ 
+   while (fd_count--)
+     close(ioctl_recv->fds[fd_count]);
+@@ -3406,10 +3412,7 @@ static int sl_handle_virtwl_socket_event(int fd, uint32_t mask, void* data) {
+   msg.msg_controllen = sizeof(fd_buffer);
+ 
+   bytes = recvmsg(ctx->virtwl_socket_fd, &msg, 0);
+-  if (bytes < 0) {
+-    fprintf(stderr, "Failed to get message from virtwl: %s\n", strerror(errno));
+-  }
+-  assert(bytes > 0);
++  errno_assert(bytes > 0);
+ 
+   // If there were any FDs recv'd by recvmsg, there will be some data in the
+   // msg_control buffer. To get the FDs out we iterate all cmsghdr's within and
+@@ -3437,11 +3440,7 @@ static int sl_handle_virtwl_socket_event(int fd, uint32_t mask, void* data) {
+   // structure which we now pass along to the kernel.
+   ioctl_send->len = bytes;
+   rv = ioctl(ctx->virtwl_ctx_fd, VIRTWL_IOCTL_SEND, ioctl_send);
+-  if (!rv) {
+-    fprintf(stderr, "Failed to send message to virtwl: %s\n", strerror(errno));
+-  }
+-  assert(!rv);
+-  UNUSED(rv);
++  errno_assert(!rv);
+ 
+   while (fd_count--)
+     close(ioctl_send->fds[fd_count]);
+@@ -3765,7 +3764,7 @@ int main(int argc, char** argv) {
+ 
+     lock_fd = open(lock_addr, O_CREAT | O_CLOEXEC,
+                    (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
+-    assert(lock_fd >= 0);
++    errno_assert(lock_fd >= 0);
+ 
+     rv = flock(lock_fd, LOCK_EX | LOCK_NB);
+     if (rv < 0) {
+@@ -3781,25 +3780,25 @@ int main(int argc, char** argv) {
+       if (sock_stat.st_mode & (S_IWUSR | S_IWGRP))
+         unlink(addr.sun_path);
+     } else {
+-      assert(errno == ENOENT);
++      errno_assert(errno == ENOENT);
+     }
+ 
+     sock_fd = socket(PF_LOCAL, SOCK_STREAM, 0);
+-    assert(sock_fd >= 0);
++    errno_assert(sock_fd >= 0);
+ 
+     rv = bind(sock_fd, (struct sockaddr*)&addr,
+               offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path));
+-    assert(rv >= 0);
++    errno_assert(rv >= 0);
+ 
+     rv = listen(sock_fd, 128);
+-    assert(rv >= 0);
++    errno_assert(rv >= 0);
+ 
+     // Spawn optional child process before we notify systemd that we're ready
+     // to accept connections. WAYLAND_DISPLAY will be set but any attempt to
+     // connect to this socket at this time will fail.
+     if (ctx.runprog && ctx.runprog[0]) {
+       pid = fork();
+-      assert(pid != -1);
++      errno_assert(pid != -1);
+       if (pid == 0) {
+         setenv("WAYLAND_DISPLAY", socket_name, 1);
+         sl_execvp(ctx.runprog[0], ctx.runprog, -1);
+@@ -3816,7 +3815,7 @@ int main(int argc, char** argv) {
+     sigemptyset(&sa.sa_mask);
+     sa.sa_flags = SA_RESTART;
+     rv = sigaction(SIGCHLD, &sa, NULL);
+-    assert(rv >= 0);
++    errno_assert(rv >= 0);
+ 
+     do {
+       struct ucred ucred;
+@@ -3833,7 +3832,7 @@ int main(int argc, char** argv) {
+       rv = getsockopt(client_fd, SOL_SOCKET, SO_PEERCRED, &ucred, &length);
+ 
+       pid = fork();
+-      assert(pid != -1);
++      errno_assert(pid != -1);
+       if (pid == 0) {
+         char* client_fd_str;
+         char* peer_pid_str;
+@@ -3963,7 +3962,7 @@ int main(int argc, char** argv) {
+ 
+       // Connection to virtwl channel.
+       rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, vws);
+-      assert(!rv);
++      errno_assert(!rv);
+ 
+       ctx.virtwl_socket_fd = vws[0];
+       virtwl_display_fd = vws[1];
+@@ -4083,7 +4082,7 @@ int main(int argc, char** argv) {
+   if (ctx.runprog || ctx.xwayland) {
+     // Wayland connection from client.
+     rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, sv);
+-    assert(!rv);
++    errno_assert(!rv);
+ 
+     client_fd = sv[0];
+   }
+@@ -4199,7 +4198,7 @@ int main(int argc, char** argv) {
+ 
+       // Xwayland display ready socket.
+       rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ds);
+-      assert(!rv);
++      errno_assert(!rv);
+ 
+       ctx.display_ready_event_source =
+           wl_event_loop_add_fd(event_loop, ds[0], WL_EVENT_READABLE,
+@@ -4207,12 +4206,12 @@ int main(int argc, char** argv) {
+ 
+       // X connection to Xwayland.
+       rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wm);
+-      assert(!rv);
++      errno_assert(!rv);
+ 
+       ctx.wm_fd = wm[0];
+ 
+       pid = fork();
+-      assert(pid != -1);
++      errno_assert(pid != -1);
+       if (pid == 0) {
+         char* display_fd_str;
+         char* wm_fd_str;
+@@ -4280,7 +4279,7 @@ int main(int argc, char** argv) {
+       ctx.xwayland_pid = pid;
+     } else {
+       pid = fork();
+-      assert(pid != -1);
++      errno_assert(pid != -1);
+       if (pid == 0) {
+         sl_execvp(ctx.runprog[0], ctx.runprog, sv[1]);
+         _exit(EXIT_FAILURE);
+-- 
+2.26.2
+
diff --git a/pkgs/os-specific/linux/chromium-os/sommelier/default.nix b/pkgs/os-specific/linux/chromium-os/sommelier/default.nix
index 669bac81628..da2a554837b 100644
--- a/pkgs/os-specific/linux/chromium-os/sommelier/default.nix
+++ b/pkgs/os-specific/linux/chromium-os/sommelier/default.nix
@@ -10,6 +10,7 @@ common-mk {
     ./0004-sommelier-don-t-leak-source-absolute-paths.patch
     ./0005-sommelier-use-stable-xdg-shell-protocol.patch
     ./0006-sommelier-make-building-demos-optional.patch
+    ./0007-vm_tools-sommelier-Log-the-value-of-strerror-when-as.patch
   ];
 
   buildInputs = [