From 2feac714c6818f7767cfc21a3c10fa926b7398a3 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Fri, 12 May 2023 08:58:19 +0100 Subject: RISC-V: fix taking the text_mutex twice during sifive errata patching 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 [] schedule+0x46/0xce [] schedule_preempt_disabled+0x16/0x28 [] __mutex_lock.constprop.0+0x3fe/0x652 [] __mutex_lock_slowpath+0xe/0x16 [] mutex_lock+0x42/0x4c [] sifive_errata_patch_func+0xf6/0x18c [] _apply_alternatives+0x74/0x76 [] apply_boot_alternatives+0x3c/0xfa [] setup_arch+0x60c/0x640 [] start_kernel+0x8e/0x99c ---[ end trace 0000000000000000 ]--- Reported-by: Chris Hofstaedtler Fixes: 9493e6f3ce02 ("RISC-V: take text_mutex during alternative patching") Signed-off-by: Conor Dooley Tested-by: Geert Uytterhoeven 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 Signed-off-by: Sasha Levin --- arch/riscv/errata/sifive/errata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index 5b77d7310e39..c24a349dd026 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; } } -- cgit v1.2.3