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 --- drivers/misc/cb710/debug.c | 115 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 drivers/misc/cb710/debug.c (limited to 'drivers/misc/cb710/debug.c') diff --git a/drivers/misc/cb710/debug.c b/drivers/misc/cb710/debug.c new file mode 100644 index 000000000..20d672edf --- /dev/null +++ b/drivers/misc/cb710/debug.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * cb710/debug.c + * + * Copyright by Michał Mirosław, 2008-2009 + */ +#include +#include +#include + +#define CB710_REG_COUNT 0x80 + +static const u16 allow[CB710_REG_COUNT/16] = { + 0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF, +}; +static const char *const prefix[ARRAY_SIZE(allow)] = { + "MMC", "MMC", "MMC", "MMC", + "MS?", "MS?", "SM?", "SM?" +}; + +static inline int allow_reg_read(unsigned block, unsigned offset, unsigned bits) +{ + unsigned mask = (1 << bits/8) - 1; + offset *= bits/8; + return ((allow[block] >> offset) & mask) == mask; +} + +#define CB710_READ_REGS_TEMPLATE(t) \ +static void cb710_read_regs_##t(void __iomem *iobase, \ + u##t *reg, unsigned select) \ +{ \ + unsigned i, j; \ + \ + for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) { \ + if (!(select & (1 << i))) \ + continue; \ + \ + for (j = 0; j < 0x10/(t/8); ++j) { \ + if (!allow_reg_read(i, j, t)) \ + continue; \ + reg[j] = ioread##t(iobase \ + + (i << 4) + (j * (t/8))); \ + } \ + } \ +} + +static const char cb710_regf_8[] = "%02X"; +static const char cb710_regf_16[] = "%04X"; +static const char cb710_regf_32[] = "%08X"; +static const char cb710_xes[] = "xxxxxxxx"; + +#define CB710_DUMP_REGS_TEMPLATE(t) \ +static void cb710_dump_regs_##t(struct device *dev, \ + const u##t *reg, unsigned select) \ +{ \ + const char *const xp = &cb710_xes[8 - t/4]; \ + const char *const format = cb710_regf_##t; \ + \ + char msg[100], *p; \ + unsigned i, j; \ + \ + for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) { \ + if (!(select & (1 << i))) \ + continue; \ + p = msg; \ + for (j = 0; j < 0x10/(t/8); ++j) { \ + *p++ = ' '; \ + if (j == 8/(t/8)) \ + *p++ = ' '; \ + if (allow_reg_read(i, j, t)) \ + p += sprintf(p, format, reg[j]); \ + else \ + p += sprintf(p, "%s", xp); \ + } \ + dev_dbg(dev, "%s 0x%02X %s\n", prefix[i], i << 4, msg); \ + } \ +} + +#define CB710_READ_AND_DUMP_REGS_TEMPLATE(t) \ +static void cb710_read_and_dump_regs_##t(struct cb710_chip *chip, \ + unsigned select) \ +{ \ + u##t regs[CB710_REG_COUNT/sizeof(u##t)]; \ + \ + memset(®s, 0, sizeof(regs)); \ + cb710_read_regs_##t(chip->iobase, regs, select); \ + cb710_dump_regs_##t(cb710_chip_dev(chip), regs, select); \ +} + +#define CB710_REG_ACCESS_TEMPLATES(t) \ + CB710_READ_REGS_TEMPLATE(t) \ + CB710_DUMP_REGS_TEMPLATE(t) \ + CB710_READ_AND_DUMP_REGS_TEMPLATE(t) + +CB710_REG_ACCESS_TEMPLATES(8) +CB710_REG_ACCESS_TEMPLATES(16) +CB710_REG_ACCESS_TEMPLATES(32) + +void cb710_dump_regs(struct cb710_chip *chip, unsigned select) +{ + if (!(select & CB710_DUMP_REGS_MASK)) + select = CB710_DUMP_REGS_ALL; + if (!(select & CB710_DUMP_ACCESS_MASK)) + select |= CB710_DUMP_ACCESS_8; + + if (select & CB710_DUMP_ACCESS_32) + cb710_read_and_dump_regs_32(chip, select); + if (select & CB710_DUMP_ACCESS_16) + cb710_read_and_dump_regs_16(chip, select); + if (select & CB710_DUMP_ACCESS_8) + cb710_read_and_dump_regs_8(chip, select); +} +EXPORT_SYMBOL_GPL(cb710_dump_regs); + -- cgit v1.3.1