From: Brian Cain <brian.cain@oss.qualcomm.com>
To: linux-hexagon@vger.kernel.org
Cc: sid.manning@oss.qualcomm.com, pierrick.bouvier@oss.qualcomm.com,
Brian Cain <brian.cain@oss.qualcomm.com>
Subject: [PATCH 1/7] hexagon: disable the LLVM packetizer
Date: Sat, 5 Sep 2026 19:17:06 -0700 [thread overview]
Message-ID: <20260906021712.2498266-2-brian.cain@oss.qualcomm.com> (raw)
In-Reply-To: <20260906021712.2498266-1-brian.cain@oss.qualcomm.com>
The Hexagon packetizer can emit invalid instruction packets at runtime.
There's multiple distinct bugs. We'll re-evaluate after 23.1.0 to see
if this can be version-gated in the future.
Disable the packetizer and new-value jumps unconditionally.
Signed-off-by: Brian Cain <brian.cain@oss.qualcomm.com>
---
arch/hexagon/Makefile | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/hexagon/Makefile b/arch/hexagon/Makefile
index ff172cbe5881..4d393bd8163a 100644
--- a/arch/hexagon/Makefile
+++ b/arch/hexagon/Makefile
@@ -7,6 +7,11 @@ KBUILD_DEFCONFIG = comet_defconfig
KBUILD_CFLAGS += -G0
LDFLAGS_vmlinux += -G0
+# Workaround for the packetizer generating invalid instruction encodings:
+# https://github.com/llvm/llvm-project/issues/178338
+# https://github.com/llvm/llvm-project/issues/218083
+KBUILD_CFLAGS += -mllvm --disable-packetizer -mllvm -disable-nvjump
+
# Do not use single-byte enums; these will overflow.
KBUILD_CFLAGS += -fno-short-enums
--
2.34.1
next prev parent reply other threads:[~2026-09-06 2:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-06 2:17 [PATCH 0/7] Hexagon build/syscall/etc fixes Brian Cain
2026-09-06 2:17 ` Brian Cain [this message]
2026-09-06 2:17 ` [PATCH 2/7] hexagon: define ELF_CORE_EFLAGS for V4-and-later architectures Brian Cain
2026-09-06 2:17 ` [PATCH 3/7] hexagon: stop passing -mv${CONFIG_HEXAGON_ARCH_VERSION} to the linker Brian Cain
2026-09-06 2:17 ` [PATCH 4/7] hexagon: read the thread-info register with a volatile asm Brian Cain
2026-09-06 2:17 ` [PATCH 5/7] hexagon: let do_work_pending return without pending work Brian Cain
2026-09-06 2:17 ` [PATCH 6/7] hexagon: set the user stack pointer in start_thread Brian Cain
2026-09-06 2:17 ` [PATCH 7/7] hexagon: return -ENOSYS for unimplemented syscalls Brian Cain
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