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/treeboot-akebono.c | 159 +++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 arch/powerpc/boot/treeboot-akebono.c (limited to 'arch/powerpc/boot/treeboot-akebono.c') diff --git a/arch/powerpc/boot/treeboot-akebono.c b/arch/powerpc/boot/treeboot-akebono.c new file mode 100644 index 000000000..1b5290374 --- /dev/null +++ b/arch/powerpc/boot/treeboot-akebono.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright © 2013 Tony Breeds IBM Corporation + * Copyright © 2013 Alistair Popple IBM Corporation + * + * Based on earlier code: + * Copyright (C) Paul Mackerras 1997. + * + * Matt Porter + * Copyright 2002-2005 MontaVista Software Inc. + * + * Eugene Surovegin or + * Copyright (c) 2003, 2004 Zultys Technologies + * + * Copyright 2007 David Gibson, IBM Corporation. + * Copyright 2010 Ben. Herrenschmidt, IBM Corporation. + * Copyright © 2011 David Kleikamp IBM Corporation + */ +#include +#include +#include "types.h" +#include "elf.h" +#include "string.h" +#include "stdlib.h" +#include "stdio.h" +#include "page.h" +#include "ops.h" +#include "reg.h" +#include "io.h" +#include "dcr.h" +#include "4xx.h" +#include "44x.h" +#include "libfdt.h" + +BSS_STACK(4096); + +#define SPRN_PIR 0x11E /* Processor Identification Register */ +#define USERDATA_LEN 256 /* Length of userdata passed in by PIBS */ +#define MAX_RANKS 0x4 +#define DDR3_MR0CF 0x80010011U +#define CCTL0_MCO2 0x8000080FU +#define CCTL0_MCO3 0x80000810U +#define CCTL0_MCO4 0x80000811U +#define CCTL0_MCO5 0x80000812U +#define CCTL0_MCO6 0x80000813U + +static unsigned long long ibm_akebono_memsize; +static long long unsigned mac_addr; + +static unsigned long long ibm_akebono_detect_memsize(void) +{ + u32 reg; + unsigned i; + unsigned long long memsize = 0; + + for (i = 0; i < MAX_RANKS; i++) { + reg = mfdcrx(DDR3_MR0CF + i); + + if (!(reg & 1)) + continue; + + reg &= 0x0000f000; + reg >>= 12; + memsize += (0x800000ULL << reg); + } + + return memsize; +} + +static void ibm_akebono_fixups(void) +{ + void *emac; + u32 reg; + + dt_fixup_memory(0x0ULL, ibm_akebono_memsize); + + /* Fixup the SD timeout frequency */ + mtdcrx(CCTL0_MCO4, 0x1); + + /* Disable SD high-speed mode (which seems to be broken) */ + reg = mfdcrx(CCTL0_MCO2) & ~0x2; + mtdcrx(CCTL0_MCO2, reg); + + /* Set the MAC address */ + emac = finddevice("/plb/opb/ethernet"); + if (emac > 0) { + if (mac_addr) + setprop(emac, "local-mac-address", + ((u8 *) &mac_addr) + 2 , 6); + } +} + +void platform_init(char *userdata) +{ + unsigned long end_of_ram, avail_ram; + u32 pir_reg; + int node, size; + const u32 *timebase; + int len, i, userdata_len; + char *end; + + userdata[USERDATA_LEN - 1] = '\0'; + userdata_len = strlen(userdata); + for (i = 0; i < userdata_len - 15; i++) { + if (strncmp(&userdata[i], "local-mac-addr=", 15) == 0) { + if (i > 0 && userdata[i - 1] != ' ') { + /* We've only found a substring ending + * with local-mac-addr so this isn't + * our mac address. */ + continue; + } + + mac_addr = strtoull(&userdata[i + 15], &end, 16); + + /* Remove the "local-mac-addr=<...>" from the kernel + * command line, including the tailing space if + * present. */ + if (*end == ' ') + end++; + + len = ((int) end) - ((int) &userdata[i]); + memmove(&userdata[i], end, + userdata_len - (len + i) + 1); + break; + } + } + + loader_info.cmdline = userdata; + loader_info.cmdline_len = 256; + + ibm_akebono_memsize = ibm_akebono_detect_memsize(); + if (ibm_akebono_memsize >> 32) + end_of_ram = ~0UL; + else + end_of_ram = ibm_akebono_memsize; + avail_ram = end_of_ram - (unsigned long)_end; + + simple_alloc_init(_end, avail_ram, 128, 64); + platform_ops.fixups = ibm_akebono_fixups; + platform_ops.exit = ibm44x_dbcr_reset; + pir_reg = mfspr(SPRN_PIR); + + /* Make sure FDT blob is sane */ + if (fdt_check_header(_dtb_start) != 0) + fatal("Invalid device tree blob\n"); + + node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type", + "cpu", sizeof("cpu")); + if (node < 0) + fatal("Cannot find cpu node\n"); + timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size); + if (timebase && (size == 4)) + timebase_period_ns = 1000000000 / *timebase; + + fdt_set_boot_cpuid_phys(_dtb_start, pir_reg); + fdt_init(_dtb_start); + + serial_console_init(); +} -- cgit v1.3.1