ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 267 insertions, 0 deletions

diff --git a/drivers/misc/cardreader/rts5209.c b/drivers/misc/cardreader/rts5209.c
new file mode 100644
index 000000000..52b0a476b
--- /dev/null
+++ b/drivers/misc/cardreader/rts5209.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Driver for Realtek PCI-Express card reader
+ *
+ * Copyright(c) 2009-2013 Realtek Semiconductor Corp. All rights reserved.
+ *
+ * Author:
+ *   Wei WANG <wei_wang@realsil.com.cn>
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/rtsx_pci.h>
+
+#include "rtsx_pcr.h"
+
+static u8 rts5209_get_ic_version(struct rtsx_pcr *pcr)
+{
+	u8 val;
+
+	val = rtsx_pci_readb(pcr, 0x1C);
+	return val & 0x0F;
+}
+
+static void rts5209_fetch_vendor_settings(struct rtsx_pcr *pcr)
+{
+	struct pci_dev *pdev = pcr->pci;
+	u32 reg;
+
+	pci_read_config_dword(pdev, PCR_SETTING_REG1, &reg);
+	pcr_dbg(pcr, "Cfg 0x%x: 0x%x\n", PCR_SETTING_REG1, reg);
+
+	if (rts5209_vendor_setting1_valid(reg)) {
+		if (rts5209_reg_check_ms_pmos(reg))
+			pcr->flags |= PCR_MS_PMOS;
+		pcr->aspm_en = rts5209_reg_to_aspm(reg);
+	}
+
+	pci_read_config_dword(pdev, PCR_SETTING_REG2, &reg);
+	pcr_dbg(pcr, "Cfg 0x%x: 0x%x\n", PCR_SETTING_REG2, reg);
+
+	if (rts5209_vendor_setting2_valid(reg)) {
+		pcr->sd30_drive_sel_1v8 =
+			rts5209_reg_to_sd30_drive_sel_1v8(reg);
+		pcr->sd30_drive_sel_3v3 =
+			rts5209_reg_to_sd30_drive_sel_3v3(reg);
+		pcr->card_drive_sel = rts5209_reg_to_card_drive_sel(reg);
+	}
+}
+
+static void rts5209_force_power_down(struct rtsx_pcr *pcr, u8 pm_state, bool runtime)
+{
+	rtsx_pci_write_register(pcr, FPDCTL, 0x07, 0x07);
+}
+
+static int rts5209_extra_init_hw(struct rtsx_pcr *pcr)
+{
+	rtsx_pci_init_cmd(pcr);
+
+	/* Turn off LED */
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_GPIO, 0xFF, 0x03);
+	/* Reset ASPM state to default value */
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, ASPM_FORCE_CTL, 0x3F, 0);
+	/* Force CLKREQ# PIN to drive 0 to request clock */
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PETXCFG, 0x08, 0x08);
+	/* Configure GPIO as output */
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_GPIO_DIR, 0xFF, 0x03);
+	/* Configure driving */
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, SD30_DRIVE_SEL,
+			0xFF, pcr->sd30_drive_sel_3v3);
+
+	return rtsx_pci_send_cmd(pcr, 100);
+}
+
+static int rts5209_optimize_phy(struct rtsx_pcr *pcr)
+{
+	return rtsx_pci_write_phy_register(pcr, 0x00, 0xB966);
+}
+
+static int rts5209_turn_on_led(struct rtsx_pcr *pcr)
+{
+	return rtsx_pci_write_register(pcr, CARD_GPIO, 0x01, 0x00);
+}
+
+static int rts5209_turn_off_led(struct rtsx_pcr *pcr)
+{
+	return rtsx_pci_write_register(pcr, CARD_GPIO, 0x01, 0x01);
+}
+
+static int rts5209_enable_auto_blink(struct rtsx_pcr *pcr)
+{
+	return rtsx_pci_write_register(pcr, CARD_AUTO_BLINK, 0xFF, 0x0D);
+}
+
+static int rts5209_disable_auto_blink(struct rtsx_pcr *pcr)
+{
+	return rtsx_pci_write_register(pcr, CARD_AUTO_BLINK, 0x08, 0x00);
+}
+
+static int rts5209_card_power_on(struct rtsx_pcr *pcr, int card)
+{
+	int err;
+	u8 pwr_mask, partial_pwr_on, pwr_on;
+
+	pwr_mask = SD_POWER_MASK;
+	partial_pwr_on = SD_PARTIAL_POWER_ON;
+	pwr_on = SD_POWER_ON;
+
+	if ((pcr->flags & PCR_MS_PMOS) && (card == RTSX_MS_CARD)) {
+		pwr_mask = MS_POWER_MASK;
+		partial_pwr_on = MS_PARTIAL_POWER_ON;
+		pwr_on = MS_POWER_ON;
+	}
+
+	rtsx_pci_init_cmd(pcr);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_PWR_CTL,
+			pwr_mask, partial_pwr_on);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
+			LDO3318_PWR_MASK, 0x04);
+	err = rtsx_pci_send_cmd(pcr, 100);
+	if (err < 0)
+		return err;
+
+	/* To avoid too large in-rush current */
+	udelay(150);
+
+	rtsx_pci_init_cmd(pcr);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_PWR_CTL, pwr_mask, pwr_on);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
+			LDO3318_PWR_MASK, 0x00);
+	return rtsx_pci_send_cmd(pcr, 100);
+}
+
+static int rts5209_card_power_off(struct rtsx_pcr *pcr, int card)
+{
+	u8 pwr_mask, pwr_off;
+
+	pwr_mask = SD_POWER_MASK;
+	pwr_off = SD_POWER_OFF;
+
+	if ((pcr->flags & PCR_MS_PMOS) && (card == RTSX_MS_CARD)) {
+		pwr_mask = MS_POWER_MASK;
+		pwr_off = MS_POWER_OFF;
+	}
+
+	rtsx_pci_init_cmd(pcr);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_PWR_CTL,
+			pwr_mask | PMOS_STRG_MASK, pwr_off | PMOS_STRG_400mA);
+	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PWR_GATE_CTRL,
+			LDO3318_PWR_MASK, 0x06);
+	return rtsx_pci_send_cmd(pcr, 100);
+}
+
+static int rts5209_switch_output_voltage(struct rtsx_pcr *pcr, u8 voltage)
+{
+	int err;
+
+	if (voltage == OUTPUT_3V3) {
+		err = rtsx_pci_write_register(pcr,
+				SD30_DRIVE_SEL, 0x07, pcr->sd30_drive_sel_3v3);
+		if (err < 0)
+			return err;
+		err = rtsx_pci_write_phy_register(pcr, 0x08, 0x4FC0 | 0x24);
+		if (err < 0)
+			return err;
+	} else if (voltage == OUTPUT_1V8) {
+		err = rtsx_pci_write_register(pcr,
+				SD30_DRIVE_SEL, 0x07, pcr->sd30_drive_sel_1v8);
+		if (err < 0)
+			return err;
+		err = rtsx_pci_write_phy_register(pcr, 0x08, 0x4C40 | 0x24);
+		if (err < 0)
+			return err;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct pcr_ops rts5209_pcr_ops = {
+	.fetch_vendor_settings = rts5209_fetch_vendor_settings,
+	.extra_init_hw = rts5209_extra_init_hw,
+	.optimize_phy = rts5209_optimize_phy,
+	.turn_on_led = rts5209_turn_on_led,
+	.turn_off_led = rts5209_turn_off_led,
+	.enable_auto_blink = rts5209_enable_auto_blink,
+	.disable_auto_blink = rts5209_disable_auto_blink,
+	.card_power_on = rts5209_card_power_on,
+	.card_power_off = rts5209_card_power_off,
+	.switch_output_voltage = rts5209_switch_output_voltage,
+	.cd_deglitch = NULL,
+	.conv_clk_and_div_n = NULL,
+	.force_power_down = rts5209_force_power_down,
+};
+
+/* SD Pull Control Enable:
+ *     SD_DAT[3:0] ==> pull up
+ *     SD_CD       ==> pull up
+ *     SD_WP       ==> pull up
+ *     SD_CMD      ==> pull up
+ *     SD_CLK      ==> pull down
+ */
+static const u32 rts5209_sd_pull_ctl_enable_tbl[] = {
+	RTSX_REG_PAIR(CARD_PULL_CTL1, 0xAA),
+	RTSX_REG_PAIR(CARD_PULL_CTL2, 0xAA),
+	RTSX_REG_PAIR(CARD_PULL_CTL3, 0xE9),
+	0,
+};
+
+/* SD Pull Control Disable:
+ *     SD_DAT[3:0] ==> pull down
+ *     SD_CD       ==> pull up
+ *     SD_WP       ==> pull down
+ *     SD_CMD      ==> pull down
+ *     SD_CLK      ==> pull down
+ */
+static const u32 rts5209_sd_pull_ctl_disable_tbl[] = {
+	RTSX_REG_PAIR(CARD_PULL_CTL1, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL2, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL3, 0xD5),
+	0,
+};
+
+/* MS Pull Control Enable:
+ *     MS CD       ==> pull up
+ *     others      ==> pull down
+ */
+static const u32 rts5209_ms_pull_ctl_enable_tbl[] = {
+	RTSX_REG_PAIR(CARD_PULL_CTL4, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL5, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL6, 0x15),
+	0,
+};
+
+/* MS Pull Control Disable:
+ *     MS CD       ==> pull up
+ *     others      ==> pull down
+ */
+static const u32 rts5209_ms_pull_ctl_disable_tbl[] = {
+	RTSX_REG_PAIR(CARD_PULL_CTL4, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL5, 0x55),
+	RTSX_REG_PAIR(CARD_PULL_CTL6, 0x15),
+	0,
+};
+
+void rts5209_init_params(struct rtsx_pcr *pcr)
+{
+	pcr->extra_caps = EXTRA_CAPS_SD_SDR50 |
+		EXTRA_CAPS_SD_SDR104 | EXTRA_CAPS_MMC_8BIT;
+	pcr->num_slots = 2;
+	pcr->ops = &rts5209_pcr_ops;
+
+	pcr->flags = 0;
+	pcr->card_drive_sel = RTS5209_CARD_DRIVE_DEFAULT;
+	pcr->sd30_drive_sel_1v8 = DRIVER_TYPE_B;
+	pcr->sd30_drive_sel_3v3 = DRIVER_TYPE_D;
+	pcr->aspm_en = ASPM_L1_EN;
+	pcr->aspm_mode = ASPM_MODE_CFG;
+	pcr->tx_initial_phase = SET_CLOCK_PHASE(27, 27, 16);
+	pcr->rx_initial_phase = SET_CLOCK_PHASE(24, 6, 5);
+
+	pcr->ic_version = rts5209_get_ic_version(pcr);
+	pcr->sd_pull_ctl_enable_tbl = rts5209_sd_pull_ctl_enable_tbl;
+	pcr->sd_pull_ctl_disable_tbl = rts5209_sd_pull_ctl_disable_tbl;
+	pcr->ms_pull_ctl_enable_tbl = rts5209_ms_pull_ctl_enable_tbl;
+	pcr->ms_pull_ctl_disable_tbl = rts5209_ms_pull_ctl_disable_tbl;
+}