ringlogger: hook into global panic writer

This is a grotesque hack, and hopefully upstream Go will provide a nicer
way of doing this, but already it seems quite adept at catching panics.
See https://github.com/golang/go/issues/42888 for more info.

This requires us to rewrite the ringlogger path to avoid all
allocations.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

14 files changed, 45 insertions, 13 deletions

diff --git a/go-patches/0001-cmd-link-recognize-arm-header-of-PE-objects.patch b/go-patches/0001-cmd-link-recognize-arm-header-of-PE-objects.patch
index 514103e7..19fdd04a 100644
--- a/go-patches/0001-cmd-link-recognize-arm-header-of-PE-objects.patch
+++ b/go-patches/0001-cmd-link-recognize-arm-header-of-PE-objects.patch
@@ -1,7 +1,7 @@
 From fde4a13eb5eba28ac546b10752b38a80f389cc5a Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Sun, 8 Nov 2020 02:48:09 +0100
-Subject: [PATCH 01/13] cmd/link: recognize arm header of PE objects
+Subject: [PATCH 01/14] cmd/link: recognize arm header of PE objects
 
 The linker recognizes headers for 386 and amd64 PE objects, but not arm
 objects. This is easily overlooked, since its the same as the 386 header
diff --git a/go-patches/0002-cmd-link-deal-with-ADDR32NB-relocations-the-same-way.patch b/go-patches/0002-cmd-link-deal-with-ADDR32NB-relocations-the-same-way.patch
index 9c4bf226..e260ccd8 100644
--- a/go-patches/0002-cmd-link-deal-with-ADDR32NB-relocations-the-same-way.patch
+++ b/go-patches/0002-cmd-link-deal-with-ADDR32NB-relocations-the-same-way.patch
@@ -1,7 +1,7 @@
 From a0a59fc25f4d8aef3c7bce38c84f04c504745f0e Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Sun, 8 Nov 2020 03:09:42 +0100
-Subject: [PATCH 02/13] cmd/link: deal with ADDR32NB relocations the same way
+Subject: [PATCH 02/14] cmd/link: deal with ADDR32NB relocations the same way
  as ADDR32 on arm
 
 As far as I can tell, the addend is the same for both of these, and in
diff --git a/go-patches/0003-cmd-link-ignore-SEH-marking-on-PE-objects.patch b/go-patches/0003-cmd-link-ignore-SEH-marking-on-PE-objects.patch
index 02d5ff31..e5c86f88 100644
--- a/go-patches/0003-cmd-link-ignore-SEH-marking-on-PE-objects.patch
+++ b/go-patches/0003-cmd-link-ignore-SEH-marking-on-PE-objects.patch
@@ -1,7 +1,7 @@
 From e8142ab5e3b3a513683a8e3792e6197644547981 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Sun, 8 Nov 2020 03:20:36 +0100
-Subject: [PATCH 03/13] cmd/link: ignore SEH marking on PE objects
+Subject: [PATCH 03/14] cmd/link: ignore SEH marking on PE objects
 
 Microsoft's linker looks at whether all input objects have an empty
 section called @feat.00. If all of them do, then it enables SEH;
diff --git a/go-patches/0004-cmd-link-do-not-mark-resource-section-as-writable.patch b/go-patches/0004-cmd-link-do-not-mark-resource-section-as-writable.patch
index cb1f82a3..1d9cb434 100644
--- a/go-patches/0004-cmd-link-do-not-mark-resource-section-as-writable.patch
+++ b/go-patches/0004-cmd-link-do-not-mark-resource-section-as-writable.patch
@@ -1,7 +1,7 @@
 From 8255e115f325a58fd4746741f9f35c2f54d70d63 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Sun, 8 Nov 2020 11:11:27 +0100
-Subject: [PATCH 04/13] cmd/link: do not mark resource section as writable
+Subject: [PATCH 04/14] cmd/link: do not mark resource section as writable
 
 Resources are immutable, and all other linkers set this section to be
 read-only and not read-write. Fix this oversight by rmoving the writable
diff --git a/go-patches/0005-cmd-link-handle-grouped-resource-sections.patch b/go-patches/0005-cmd-link-handle-grouped-resource-sections.patch
index 9e11d775..02af61a2 100644
--- a/go-patches/0005-cmd-link-handle-grouped-resource-sections.patch
+++ b/go-patches/0005-cmd-link-handle-grouped-resource-sections.patch
@@ -1,7 +1,7 @@
 From 5d5d74f35dd3375cda8ef2ba8257547aad107ecb Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Sun, 8 Nov 2020 11:57:42 +0100
-Subject: [PATCH 05/13] cmd/link: handle grouped resource sections
+Subject: [PATCH 05/14] cmd/link: handle grouped resource sections
 
 The Go PE linker does not support enough generalized PE logic to
 properly handle .rsrc sections gracefully. Instead a few things are
diff --git a/go-patches/0006-Revert-release-branch.go1.15-runtime-detect-services.patch b/go-patches/0006-Revert-release-branch.go1.15-runtime-detect-services.patch
index 3cb0bdd2..cb21af9f 100644
--- a/go-patches/0006-Revert-release-branch.go1.15-runtime-detect-services.patch
+++ b/go-patches/0006-Revert-release-branch.go1.15-runtime-detect-services.patch
@@ -1,7 +1,7 @@
 From e6b4c1b3beb4f843ed40abead27c8132d29a0db8 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Fri, 11 Sep 2020 13:04:11 +0200
-Subject: [PATCH 06/13] Revert "[release-branch.go1.15] runtime: detect
+Subject: [PATCH 06/14] Revert "[release-branch.go1.15] runtime: detect
  services in signal handler"
 
 This reverts commit b1253d24e159129c778377c3a2a0bde15904a417.
diff --git a/go-patches/0007-runtime-do-not-explicitly-exit-on-ctrl-handler.patch b/go-patches/0007-runtime-do-not-explicitly-exit-on-ctrl-handler.patch
index 8479c1cc..4db19853 100644
--- a/go-patches/0007-runtime-do-not-explicitly-exit-on-ctrl-handler.patch
+++ b/go-patches/0007-runtime-do-not-explicitly-exit-on-ctrl-handler.patch
@@ -1,7 +1,7 @@
 From af4eb34d920c0c727041ebf587e0de608068ed59 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Tue, 14 Jul 2020 01:41:03 -0600
-Subject: [PATCH 07/13] runtime: do not explicitly exit on ctrl handler
+Subject: [PATCH 07/14] runtime: do not explicitly exit on ctrl handler
 
 The default ctrl+c handler should process exits in situations where it
 makes sense, like console apps, but not in situations where it doesn't,
diff --git a/go-patches/0008-runtime-allow-callback-functions-with-up-to-8-argume.patch b/go-patches/0008-runtime-allow-callback-functions-with-up-to-8-argume.patch
index 186610ae..0af97ce2 100644
--- a/go-patches/0008-runtime-allow-callback-functions-with-up-to-8-argume.patch
+++ b/go-patches/0008-runtime-allow-callback-functions-with-up-to-8-argume.patch
@@ -1,7 +1,7 @@
 From 5a7c808cbacb8c0477395c5656c1eba3ef38cd6e Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Tue, 10 Nov 2020 21:42:36 +0100
-Subject: [PATCH 08/13] runtime: allow callback functions with up to 8
+Subject: [PATCH 08/14] runtime: allow callback functions with up to 8
  arguments on windows/arm
 
 Previously, windows/arm programs would abort when trying to use
diff --git a/go-patches/0009-runtime-use-CreateWaitableTimerEx-to-implement-uslee.patch b/go-patches/0009-runtime-use-CreateWaitableTimerEx-to-implement-uslee.patch
index 90604341..83647c59 100644
--- a/go-patches/0009-runtime-use-CreateWaitableTimerEx-to-implement-uslee.patch
+++ b/go-patches/0009-runtime-use-CreateWaitableTimerEx-to-implement-uslee.patch
@@ -1,7 +1,7 @@
 From 1a163f2e676e4664f2db3f614eb4168bda9d4fd8 Mon Sep 17 00:00:00 2001
 From: Alex Brainman <alex.brainman@gmail.com>
 Date: Sun, 19 Jul 2020 16:06:48 +1000
-Subject: [PATCH 09/13] runtime: use CreateWaitableTimerEx to implement usleep
+Subject: [PATCH 09/14] runtime: use CreateWaitableTimerEx to implement usleep
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
diff --git a/go-patches/0010-runtime-allow-for-usleep2HighRes-to-run-without-TLS-.patch b/go-patches/0010-runtime-allow-for-usleep2HighRes-to-run-without-TLS-.patch
index 3fe6935e..1c25f5b6 100644
--- a/go-patches/0010-runtime-allow-for-usleep2HighRes-to-run-without-TLS-.patch
+++ b/go-patches/0010-runtime-allow-for-usleep2HighRes-to-run-without-TLS-.patch
@@ -1,7 +1,7 @@
 From 1edac4879e2d4a36d339353c151cb7b9871e135f Mon Sep 17 00:00:00 2001
 From: Alex Brainman <alex.brainman@gmail.com>
 Date: Sat, 21 Nov 2020 14:56:26 +1100
-Subject: [PATCH 10/13] runtime: allow for usleep2HighRes to run without TLS
+Subject: [PATCH 10/14] runtime: allow for usleep2HighRes to run without TLS
  setup
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
diff --git a/go-patches/0011-cmd-link-windows-arm-is-all-pie-so-mark-it-as-such.patch b/go-patches/0011-cmd-link-windows-arm-is-all-pie-so-mark-it-as-such.patch
index 72cbb000..a2984678 100644
--- a/go-patches/0011-cmd-link-windows-arm-is-all-pie-so-mark-it-as-such.patch
+++ b/go-patches/0011-cmd-link-windows-arm-is-all-pie-so-mark-it-as-such.patch
@@ -1,7 +1,7 @@
 From fee7906e1a7e62b655bea0f25c921572ee29fc44 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Thu, 26 Nov 2020 22:38:45 +0100
-Subject: [PATCH 11/13] cmd/link: windows/arm is all pie, so mark it as such
+Subject: [PATCH 11/14] cmd/link: windows/arm is all pie, so mark it as such
 
 If the linker thinks that it's making an exe instead of a pie object, it
 won't apply relocations to the pclntab and we wind up with crashes like:
diff --git a/go-patches/0012-runtime-adjust-address-calculation-in-identifying-ab.patch b/go-patches/0012-runtime-adjust-address-calculation-in-identifying-ab.patch
index 2f3954db..38fcbb9b 100644
--- a/go-patches/0012-runtime-adjust-address-calculation-in-identifying-ab.patch
+++ b/go-patches/0012-runtime-adjust-address-calculation-in-identifying-ab.patch
@@ -1,7 +1,7 @@
 From 8ec41fee1e6ef074ef74e56fe079c70c8a1d0548 Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Fri, 27 Nov 2020 22:07:23 +0100
-Subject: [PATCH 12/13] runtime: adjust address calculation in identifying
+Subject: [PATCH 12/14] runtime: adjust address calculation in identifying
  abort on windows/arm
 
 Apparently we're being called on arm 1 byte off, just like on 386 and
diff --git a/go-patches/0013-cmd-compile-do-not-assume-TST-and-TEQ-set-V-on-arm.patch b/go-patches/0013-cmd-compile-do-not-assume-TST-and-TEQ-set-V-on-arm.patch
index 296ca4a2..a8eb403d 100644
--- a/go-patches/0013-cmd-compile-do-not-assume-TST-and-TEQ-set-V-on-arm.patch
+++ b/go-patches/0013-cmd-compile-do-not-assume-TST-and-TEQ-set-V-on-arm.patch
@@ -1,7 +1,7 @@
 From 58e426bb8175959d7bf32ea7c87e51f4706b309b Mon Sep 17 00:00:00 2001
 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
 Date: Mon, 30 Nov 2020 10:41:46 +0100
-Subject: [PATCH 13/13] cmd/compile: do not assume TST and TEQ set V on arm
+Subject: [PATCH 13/14] cmd/compile: do not assume TST and TEQ set V on arm
 
 These replacement rules assume that TST and TEQ set V. But TST and
 TEQ do not set V. This is a problem because instructions like LT are
diff --git a/go-patches/0014-runtime-make-write-into-function-pointer.patch b/go-patches/0014-runtime-make-write-into-function-pointer.patch
new file mode 100644
index 00000000..1618f02e
--- /dev/null
+++ b/go-patches/0014-runtime-make-write-into-function-pointer.patch
@@ -0,0 +1,32 @@
+From d7b6f2bfcee5787d9055f5d7ec92c74e258e8fab Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Thu, 3 Dec 2020 13:29:58 +0100
+Subject: [PATCH 14/14] runtime: make write into function pointer
+
+Change-Id: I77a32ff7e1494324e8cc38e792e007f86d32672d
+---
+ src/runtime/time_nofake.go | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/src/runtime/time_nofake.go b/src/runtime/time_nofake.go
+index 1912a94e87..0564448b2e 100644
+--- a/src/runtime/time_nofake.go
++++ b/src/runtime/time_nofake.go
+@@ -23,9 +23,14 @@ func walltime() (sec int64, nsec int32) {
+ 	return walltime1()
+ }
+ 
++var overrideWrite func(fd uintptr, p unsafe.Pointer, n int32) int32
++
+ // write must be nosplit on Windows (see write1)
+ //
+ //go:nosplit
+ func write(fd uintptr, p unsafe.Pointer, n int32) int32 {
++	if overrideWrite != nil {
++		return overrideWrite(fd, noescape(p), n)
++	}
+ 	return write1(fd, p, n)
+ }
+-- 
+2.29.2
+