On Tue, Mar 07, 2023 at 05:00:38PM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 6.1-stable tree.
This patch has a bug and shouldn't be backported as-is anyway, as it breaks boot on some platforms. I'll do something about this patch once the fix lands too.
Same applies to whatever other trees it's been attempted to be backported too.
Cheers, Conor.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 9493e6f3ce02f44c21aa19f3cbf3b9aa05479d06 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '1678204838254140@kroah.com' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
9493e6f3ce02 ("RISC-V: take text_mutex during alternative patching") bfd6fc5d8014 ("riscv: Fix early alternative patching") 8d23e94a4433 ("riscv: switch to relative alternative entries") 4bf8860760d9 ("riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions") abcc445acdbe ("riscv: move riscv_noncoherent_supported() out of ZICBOM probe") 61a9b7129070 ("Merge patch series "Putting some basic order on isa extension lists"")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9493e6f3ce02f44c21aa19f3cbf3b9aa05479d06 Mon Sep 17 00:00:00 2001
From: Conor Dooley conor.dooley@microchip.com Date: Sun, 12 Feb 2023 19:47:36 +0000 Subject: [PATCH] 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 702e64550b12 ("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: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support") Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") Fixes: 1a0e5dbd3723 ("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
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index ef9a4eec0dba..da55cb247e89 100644 --- a/arch/riscv/errata/sifive/errata.c +++ b/arch/riscv/errata/sifive/errata.c @@ -4,6 +4,7 @@ */ #include <linux/kernel.h> +#include <linux/memory.h> #include <linux/module.h> #include <linux/string.h> #include <linux/bug.h> @@ -107,8 +108,10 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin, tmp = (1U << alt->errata_id); if (cpu_req_errata & tmp) {
mutex_lock(&text_mutex); patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt), alt->alt_len);mutex_lock(&text_mutex); cpu_apply_errata |= tmp;diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c index 1dd90a5f86f0..3b96a06d3c54 100644 --- a/arch/riscv/errata/thead/errata.c +++ b/arch/riscv/errata/thead/errata.c @@ -5,6 +5,7 @@ #include <linux/bug.h> #include <linux/kernel.h> +#include <linux/memory.h> #include <linux/module.h> #include <linux/string.h> #include <linux/uaccess.h> @@ -101,10 +102,13 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al altptr = ALT_ALT_PTR(alt); /* On vm-alternatives, the mmu isn't running yet */
if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) { memcpy(oldptr, altptr, alt->alt_len);
else
} else {mutex_lock(&text_mutex); patch_text_nosync(oldptr, altptr, alt->alt_len);mutex_unlock(&text_mutex);}diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 21fb567e1b22..59d58ee0f68d 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -10,6 +10,7 @@ #include <linux/ctype.h> #include <linux/libfdt.h> #include <linux/log2.h> +#include <linux/memory.h> #include <linux/module.h> #include <linux/of.h> #include <asm/alternative.h> @@ -292,8 +293,11 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, oldptr = ALT_OLD_PTR(alt); altptr = ALT_ALT_PTR(alt);
mutex_lock(&text_mutex);mutex_unlock(&text_mutex);} #endif