From: Conor Dooley <conor@kernel.org>
Date: Thu, 2 Mar 2023 17:41:55 +0000
Subject: [PATCH] RISC-V: fix taking the text_mutex twice during sifive errata
patching
References: bsc#1012628
Patch-mainline: 6.2.7
Git-commit: bf89b7ee52af5a5944fa3539e86089f72475055b
commit bf89b7ee52af5a5944fa3539e86089f72475055b upstream.
Chris pointed out that some bonehead, *cough* me *cough*, added two
mutex_locks() to the SiFive errata patching. The second was meant to
have been a mutex_unlock().
This results in errors such as
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000030
Oops [#1]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted
6.2.0-rc1-starlight-00079-g9493e6f3ce02 #229
Hardware name: BeagleV Starlight Beta (DT)
epc : __schedule+0x42/0x500
ra : schedule+0x46/0xce
epc : ffffffff8065957c ra : ffffffff80659a80 sp : ffffffff81203c80
gp : ffffffff812d50a0 tp : ffffffff8120db40 t0 : ffffffff81203d68
t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81203cf0
s1 : ffffffff8120db40 a0 : 0000000000000000 a1 : ffffffff81213958
a2 : ffffffff81213958 a3 : 0000000000000000 a4 : 0000000000000000
a5 : ffffffff80a1bd00 a6 : 0000000000000000 a7 : 0000000052464e43
s2 : ffffffff8120db41 s3 : ffffffff80a1ad00 s4 : 0000000000000000
s5 : 0000000000000002 s6 : ffffffff81213938 s7 : 0000000000000000
s8 : 0000000000000000 s9 : 0000000000000001 s10: ffffffff812d7204
s11: ffffffff80d3c920 t3 : 0000000000000001 t4 : ffffffff812e6dd7
t5 : ffffffff812e6dd8 t6 : ffffffff81203bb8
status: 0000000200000100 badaddr: 0000000000000030 cause: 000000000000000d
[<ffffffff80659a80>] schedule+0x46/0xce
[<ffffffff80659dce>] schedule_preempt_disabled+0x16/0x28
[<ffffffff8065ae0c>] __mutex_lock.constprop.0+0x3fe/0x652
[<ffffffff8065b138>] __mutex_lock_slowpath+0xe/0x16
[<ffffffff8065b182>] mutex_lock+0x42/0x4c
[<ffffffff8000ad94>] sifive_errata_patch_func+0xf6/0x18c
[<ffffffff80002b92>] _apply_alternatives+0x74/0x76
[<ffffffff80802ee8>] apply_boot_alternatives+0x3c/0xfa
[<ffffffff80803cb0>] setup_arch+0x60c/0x640
[<ffffffff80800926>] start_kernel+0x8e/0x99c
---[ end trace 0000000000000000 ]---
Reported-by: Chris Hofstaedtler <zeha@debian.org>
Fixes: 9493e6f3ce02 ("RISC-V: take text_mutex during alternative patching")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230302174154.970746-1-conor@kernel.org
[Palmer: pick up Geert's bug report from the thread]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/riscv/errata/sifive/errata.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index 5b77d731..c24a349d 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -110,7 +110,7 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin,
if (cpu_req_errata & tmp) {
mutex_lock(&text_mutex);
patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
- mutex_lock(&text_mutex);
+ mutex_unlock(&text_mutex);
cpu_apply_errata |= tmp;
}
}
--
2.35.3