From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/clk/qcom/common.h | 92 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 drivers/clk/qcom/common.h (limited to 'drivers/clk/qcom/common.h') diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h new file mode 100644 index 000000000..6f2406f88 --- /dev/null +++ b/drivers/clk/qcom/common.h @@ -0,0 +1,92 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2014, The Linux Foundation. All rights reserved. */ + +#ifndef __QCOM_CLK_COMMON_H__ +#define __QCOM_CLK_COMMON_H__ + +struct platform_device; +struct regmap_config; +struct clk_regmap; +struct qcom_reset_map; +struct regmap; +struct freq_tbl; +struct clk_hw; + +#define PLL_LOCK_COUNT_SHIFT 8 +#define PLL_LOCK_COUNT_MASK 0x3f +#define PLL_BIAS_COUNT_SHIFT 14 +#define PLL_BIAS_COUNT_MASK 0x3f +#define PLL_VOTE_FSM_ENA BIT(20) +#define PLL_VOTE_FSM_RESET BIT(21) + +struct qcom_icc_hws_data { + int master_id; + int slave_id; + int clk_id; +}; + +struct qcom_cc_driver_data { + struct clk_alpha_pll **alpha_plls; + size_t num_alpha_plls; + const u32 *clk_cbcrs; + size_t num_clk_cbcrs; + const struct clk_rcg_dfs_data *dfs_rcgs; + size_t num_dfs_rcgs; + void (*clk_regs_configure)(struct device *dev, struct regmap *regmap); +}; + +struct qcom_cc_desc { + const struct regmap_config *config; + struct clk_regmap **clks; + size_t num_clks; + const struct qcom_reset_map *resets; + size_t num_resets; + struct gdsc **gdscs; + size_t num_gdscs; + struct clk_hw **clk_hws; + size_t num_clk_hws; + const struct qcom_icc_hws_data *icc_hws; + size_t num_icc_hws; + unsigned int icc_first_node_id; + bool use_rpm; + const struct qcom_cc_driver_data *driver_data; +}; + +/** + * struct parent_map - map table for source select configuration values + * @src: source + * @cfg: configuration value + */ +struct parent_map { + u8 src; + u8 cfg; +}; + +extern const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, + unsigned long rate); +extern const struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f, + unsigned long rate); +extern const struct freq_multi_tbl *qcom_find_freq_multi(const struct freq_multi_tbl *f, + unsigned long rate); +extern void +qcom_pll_set_fsm_mode(struct regmap *m, u32 reg, u8 bias_count, u8 lock_count); +extern int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map, + u8 src); +extern int qcom_find_cfg_index(struct clk_hw *hw, const struct parent_map *map, + u8 cfg); + +extern int qcom_cc_register_board_clk(struct device *dev, const char *path, + const char *name, unsigned long rate); +extern int qcom_cc_register_sleep_clk(struct device *dev); + +extern struct regmap *qcom_cc_map(struct platform_device *pdev, + const struct qcom_cc_desc *desc); +extern int qcom_cc_really_probe(struct device *dev, + const struct qcom_cc_desc *desc, + struct regmap *regmap); +extern int qcom_cc_probe(struct platform_device *pdev, + const struct qcom_cc_desc *desc); +extern int qcom_cc_probe_by_index(struct platform_device *pdev, int index, + const struct qcom_cc_desc *desc); + +#endif -- cgit v1.3.1