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/ti/interface.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 drivers/clk/ti/interface.c (limited to 'drivers/clk/ti/interface.c') diff --git a/drivers/clk/ti/interface.c b/drivers/clk/ti/interface.c new file mode 100644 index 000000000..039c8075e --- /dev/null +++ b/drivers/clk/ti/interface.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * OMAP interface clock support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * Tero Kristo + */ + +#include +#include +#include +#include +#include +#include "clock.h" + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +static const struct clk_ops ti_interface_clk_ops = { + .init = &omap2_init_clk_clkdm, + .enable = &omap2_dflt_clk_enable, + .disable = &omap2_dflt_clk_disable, + .is_enabled = &omap2_dflt_clk_is_enabled, +}; + +static struct clk *_register_interface(struct device_node *node, + const char *name, + const char *parent_name, + struct clk_omap_reg *reg, u8 bit_idx, + const struct clk_hw_omap_ops *ops) +{ + struct clk_init_data init = { NULL }; + struct clk_hw_omap *clk_hw; + struct clk *clk; + + clk_hw = kzalloc_obj(*clk_hw); + if (!clk_hw) + return ERR_PTR(-ENOMEM); + + clk_hw->hw.init = &init; + clk_hw->ops = ops; + memcpy(&clk_hw->enable_reg, reg, sizeof(*reg)); + clk_hw->enable_bit = bit_idx; + + init.name = name; + init.ops = &ti_interface_clk_ops; + init.flags = 0; + + init.num_parents = 1; + init.parent_names = &parent_name; + + clk = of_ti_clk_register_omap_hw(node, &clk_hw->hw, name); + + if (IS_ERR(clk)) + kfree(clk_hw); + + return clk; +} + +static void __init _of_ti_interface_clk_setup(struct device_node *node, + const struct clk_hw_omap_ops *ops) +{ + struct clk *clk; + const char *parent_name; + struct clk_omap_reg reg; + u8 enable_bit = 0; + const char *name; + + if (ti_clk_get_reg_addr(node, 0, ®)) + return; + + enable_bit = reg.bit; + + parent_name = of_clk_get_parent_name(node, 0); + if (!parent_name) { + pr_err("%pOFn must have a parent\n", node); + return; + } + + name = ti_dt_clk_name(node); + clk = _register_interface(node, name, parent_name, ®, + enable_bit, ops); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); +} + +static void __init of_ti_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, &clkhwops_iclk_wait); +} +CLK_OF_DECLARE(ti_interface_clk, "ti,omap3-interface-clock", + of_ti_interface_clk_setup); + +static void __init of_ti_no_wait_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, &clkhwops_iclk); +} +CLK_OF_DECLARE(ti_no_wait_interface_clk, "ti,omap3-no-wait-interface-clock", + of_ti_no_wait_interface_clk_setup); + +#ifdef CONFIG_ARCH_OMAP3 +static void __init of_ti_hsotgusb_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, + &clkhwops_omap3430es2_iclk_hsotgusb_wait); +} +CLK_OF_DECLARE(ti_hsotgusb_interface_clk, "ti,omap3-hsotgusb-interface-clock", + of_ti_hsotgusb_interface_clk_setup); + +static void __init of_ti_dss_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, + &clkhwops_omap3430es2_iclk_dss_usbhost_wait); +} +CLK_OF_DECLARE(ti_dss_interface_clk, "ti,omap3-dss-interface-clock", + of_ti_dss_interface_clk_setup); + +static void __init of_ti_ssi_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, &clkhwops_omap3430es2_iclk_ssi_wait); +} +CLK_OF_DECLARE(ti_ssi_interface_clk, "ti,omap3-ssi-interface-clock", + of_ti_ssi_interface_clk_setup); + +static void __init of_ti_am35xx_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, &clkhwops_am35xx_ipss_wait); +} +CLK_OF_DECLARE(ti_am35xx_interface_clk, "ti,am35xx-interface-clock", + of_ti_am35xx_interface_clk_setup); +#endif + +#ifdef CONFIG_SOC_OMAP2430 +static void __init of_ti_omap2430_interface_clk_setup(struct device_node *node) +{ + _of_ti_interface_clk_setup(node, &clkhwops_omap2430_i2chs_wait); +} +CLK_OF_DECLARE(ti_omap2430_interface_clk, "ti,omap2430-interface-clock", + of_ti_omap2430_interface_clk_setup); +#endif -- cgit v1.3.1