Conor Dooley 9493e6f3ce RISC-V: take text_mutex during alternative patching ... Guenter reported a splat during boot, that Samuel pointed out was the lockdep assertion failing in patch_insn_write(): WARNING: CPU: 0 PID: 0 at arch/riscv/kernel/patch.c:63 patch_insn_write+0x222/0x2f6 epc : patch_insn_write+0x222/0x2f6 ra : patch_insn_write+0x21e/0x2f6 epc : ffffffff800068c6 ra : ffffffff800068c2 sp : ffffffff81803df0 gp : ffffffff81a1ab78 tp : ffffffff81814f80 t0 : ffffffffffffe000 t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81803e40 s1 : 0000000000000004 a0 : 0000000000000000 a1 : ffffffffffffffff a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000001 a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43 s2 : ffffffff80b4889c s3 : 000000000000082c s4 : ffffffff80b48828 s5 : 0000000000000828 s6 : ffffffff8131a0a0 s7 : 0000000000000fff s8 : 0000000008000200 s9 : ffffffff8131a520 s10: 0000000000000018 s11: 000000000000000b t3 : 0000000000000001 t4 : 000000000000000d t5 : ffffffffd8180000 t6 : ffffffff81803bc8 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [<ffffffff800068c6>] patch_insn_write+0x222/0x2f6 [<ffffffff80006a36>] patch_text_nosync+0xc/0x2a [<ffffffff80003b86>] riscv_cpufeature_patch_func+0x52/0x98 [<ffffffff80003348>] _apply_alternatives+0x46/0x86 [<ffffffff80c02d36>] apply_boot_alternatives+0x3c/0xfa [<ffffffff80c03ad8>] setup_arch+0x584/0x5b8 [<ffffffff80c0075a>] start_kernel+0xa2/0x8f8 This issue was exposed by 702e64550b ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()"), as it is the patching in has_fpu() that triggers the splats in Guenter's report. Take the text_mutex before doing any code patching to satisfy lockdep. Fixes: ff689fd21c ("riscv: add RISC-V Svpbmt extension support") Fixes: a35707c3d8 ("riscv: add memory-type errata for T-Head") Fixes: 1a0e5dbd37 ("riscv: sifive: Add SiFive alternative ports") Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/20230212154333.GA3760469@roeck-us.net/ Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230212194735.491785-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2023-02-21 17:21:33 -08:00
..
Makefile	riscv: add memory-type errata for T-Head	2022-05-11 21:36:33 -07:00
errata.c	RISC-V: take text_mutex during alternative patching	2023-02-21 17:21:33 -08:00