From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/powerpc/boot/string.S | 252 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 arch/powerpc/boot/string.S (limited to 'arch/powerpc/boot/string.S') diff --git a/arch/powerpc/boot/string.S b/arch/powerpc/boot/string.S new file mode 100644 index 000000000..76801eb6d --- /dev/null +++ b/arch/powerpc/boot/string.S @@ -0,0 +1,252 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) Paul Mackerras 1997. + * + * NOTE: this code runs in 32 bit mode and is packaged as ELF32. + */ + +#include "ppc_asm.h" + + .text + .globl strcpy +strcpy: + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r5) + bne 1b + blr + + .globl strcat +strcat: + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r0,1(r5) + cmpwi 0,r0,0 + bne 1b + addi r5,r5,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r5) + bne 1b + blr + + .globl strchr +strchr: + addi r3,r3,-1 +1: lbzu r0,1(r3) + cmpw 0,r0,r4 + beqlr + cmpwi 0,r0,0 + bne 1b + li r3,0 + blr + + .globl strcmp +strcmp: + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r3,1(r5) + cmpwi 1,r3,0 + lbzu r0,1(r4) + subf. r3,r0,r3 + beqlr 1 + beq 1b + blr + + .globl strncmp +strncmp: + mtctr r5 + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r3,1(r5) + cmpwi 1,r3,0 + lbzu r0,1(r4) + subf. r3,r0,r3 + beqlr 1 + bdnzt eq,1b + blr + + .globl strlen +strlen: + addi r4,r3,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + bne 1b + subf r3,r3,r4 + blr + + .globl memset +memset: + rlwimi r4,r4,8,16,23 + rlwimi r4,r4,16,0,15 + addi r6,r3,-4 + cmplwi 0,r5,4 + blt 7f + stwu r4,4(r6) + beqlr + andi. r0,r6,3 + add r5,r0,r5 + subf r6,r0,r6 + rlwinm r0,r5,32-2,2,31 + mtctr r0 + bdz 6f +1: stwu r4,4(r6) + bdnz 1b +6: andi. r5,r5,3 +7: cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r6,r6,3 +8: stbu r4,1(r6) + bdnz 8b + blr + + .globl memmove +memmove: + cmplw 0,r3,r4 + bgt backwards_memcpy + /* fall through */ + + .globl memcpy +memcpy: + rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */ + addi r6,r3,-4 + addi r4,r4,-4 + beq 3f /* if less than 8 bytes to do */ + andi. r0,r6,3 /* get dest word aligned */ + mtctr r7 + bne 5f + andi. r0,r4,3 /* check src word aligned too */ + bne 3f +1: lwz r7,4(r4) + lwzu r8,8(r4) + stw r7,4(r6) + stwu r8,8(r6) + bdnz 1b + andi. r5,r5,7 +2: cmplwi 0,r5,4 + blt 3f + lwzu r0,4(r4) + addi r5,r5,-4 + stwu r0,4(r6) +3: cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r4,r4,3 + addi r6,r6,3 +4: lbzu r0,1(r4) + stbu r0,1(r6) + bdnz 4b + blr +5: subfic r0,r0,4 + cmpw cr1,r0,r5 + add r7,r0,r4 + andi. r7,r7,3 /* will source be word-aligned too? */ + ble cr1,3b + bne 3b /* do byte-by-byte if not */ + mtctr r0 +6: lbz r7,4(r4) + addi r4,r4,1 + stb r7,4(r6) + addi r6,r6,1 + bdnz 6b + subf r5,r0,r5 + rlwinm. r7,r5,32-3,3,31 + beq 2b + mtctr r7 + b 1b + + .globl backwards_memcpy +backwards_memcpy: + rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */ + add r6,r3,r5 + add r4,r4,r5 + beq 3f + andi. r0,r6,3 + mtctr r7 + bne 5f + andi. r0,r4,3 + bne 3f +1: lwz r7,-4(r4) + lwzu r8,-8(r4) + stw r7,-4(r6) + stwu r8,-8(r6) + bdnz 1b + andi. r5,r5,7 +2: cmplwi 0,r5,4 + blt 3f + lwzu r0,-4(r4) + subi r5,r5,4 + stwu r0,-4(r6) +3: cmpwi 0,r5,0 + beqlr + mtctr r5 +4: lbzu r0,-1(r4) + stbu r0,-1(r6) + bdnz 4b + blr +5: cmpw cr1,r0,r5 + subf r7,r0,r4 + andi. r7,r7,3 + ble cr1,3b + bne 3b + mtctr r0 +6: lbzu r7,-1(r4) + stbu r7,-1(r6) + bdnz 6b + subf r5,r0,r5 + rlwinm. r7,r5,32-3,3,31 + beq 2b + mtctr r7 + b 1b + + .globl memchr +memchr: + cmpwi 0,r5,0 + blelr + mtctr r5 + addi r3,r3,-1 +1: lbzu r0,1(r3) + cmpw r0,r4 + beqlr + bdnz 1b + li r3,0 + blr + + .globl memcmp +memcmp: + cmpwi 0,r5,0 + ble 2f + mtctr r5 + addi r6,r3,-1 + addi r4,r4,-1 +1: lbzu r3,1(r6) + lbzu r0,1(r4) + subf. r3,r0,r3 + bdnzt 2,1b + blr +2: li r3,0 + blr + + +/* + * Flush the dcache and invalidate the icache for a range of addresses. + * + * flush_cache(addr, len) + */ + .global flush_cache +flush_cache: + addi 4,4,0x1f /* len = (len + 0x1f) / 0x20 */ + rlwinm. 4,4,27,5,31 + mtctr 4 + beqlr +1: dcbf 0,3 + icbi 0,3 + addi 3,3,0x20 + bdnz 1b + sync + isync + blr + -- cgit v1.3.1