From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Nathan Huckleberry <nhuck@google.com>,
Palmer Dabbelt <palmerdabbelt@google.com>,
Sasha Levin <sashal@kernel.org>,
linux-riscv@lists.infradead.org,
clang-built-linux@googlegroups.com
Subject: [PATCH AUTOSEL 4.19 04/15] riscv/atomic: Fix sign extension for RV64I
Date: Tue, 23 Jun 2020 13:36:19 -0400 [thread overview]
Message-ID: <20200623173630.1355971-4-sashal@kernel.org> (raw)
In-Reply-To: <20200623173630.1355971-1-sashal@kernel.org>
From: Nathan Huckleberry <nhuck@google.com>
[ Upstream commit 6c58f25e6938c073198af8b1e1832f83f8f0df33 ]
The argument passed to cmpxchg is not guaranteed to be sign
extended, but lr.w sign extends on RV64I. This makes cmpxchg
fail on clang built kernels when __old is negative.
To fix this, we just cast __old to long which sign extends on
RV64I. With this fix, clang built RISC-V kernels now boot.
Link: https://github.com/ClangBuiltLinux/linux/issues/867
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/riscv/include/asm/cmpxchg.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h
index c12833f7b6bd1..42978aac99d53 100644
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
@@ -187,7 +187,7 @@
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
+ : "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
@@ -232,7 +232,7 @@
RISCV_ACQUIRE_BARRIER \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
+ : "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
@@ -278,7 +278,7 @@
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
+ : "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
@@ -324,7 +324,7 @@
" fence rw, rw\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
+ : "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
--
2.25.1
next prev parent reply other threads:[~2020-06-23 17:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 17:36 [PATCH AUTOSEL 4.19 01/15] sata_rcar: handle pm_runtime_get_sync failure cases Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 02/15] ata/libata: Fix usage of page address by page_address in ata_scsi_mode_select_xlat function Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 03/15] drm/amd/display: Use kfree() to free rgb_user in calculate_user_regamma_ramp() Sasha Levin
2020-06-23 17:36 ` Sasha Levin [this message]
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 05/15] hwrng: ks-sa - Fix runtime PM imbalance on error Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 06/15] arm64/sve: Eliminate data races on sve_default_vl Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 07/15] ibmvnic: Harden device login requests Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 08/15] net: alx: fix race condition in alx_remove Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 09/15] rocker: fix incorrect error handling in dma_rings_init Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 10/15] s390/ptrace: fix setting syscall number Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 11/15] s390/vdso: fix vDSO clock_getres() Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 12/15] arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=n Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 13/15] kbuild: improve cc-option to clean up all temporary files Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 14/15] blktrace: break out of blktrace setup on concurrent calls Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 15/15] RISC-V: Don't allow write+exec only page mapping request in mmap Sasha Levin
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