From f4cdf7ca9a1fdcca413157df19753f388a5a224e Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 19 Aug 2026 10:09:22 -0700 Subject: Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ... --- lib/syscall.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 lib/syscall.c (limited to 'lib/syscall.c') diff --git a/lib/syscall.c b/lib/syscall.c new file mode 100644 index 000000000..006e256d2 --- /dev/null +++ b/lib/syscall.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +static int collect_syscall(struct task_struct *target, struct syscall_info *info) +{ + unsigned long args[6] = { }; + struct pt_regs *regs; + + if (!try_get_task_stack(target)) { + /* Task has no stack, so the task isn't in a syscall. */ + memset(info, 0, sizeof(*info)); + info->data.nr = -1; + return 0; + } + + regs = task_pt_regs(target); + if (unlikely(!regs)) { + put_task_stack(target); + return -EAGAIN; + } + + info->sp = user_stack_pointer(regs); + info->data.instruction_pointer = instruction_pointer(regs); + + info->data.nr = syscall_get_nr(target, regs); + if (info->data.nr != -1L) + syscall_get_arguments(target, regs, args); + + info->data.args[0] = args[0]; + info->data.args[1] = args[1]; + info->data.args[2] = args[2]; + info->data.args[3] = args[3]; + info->data.args[4] = args[4]; + info->data.args[5] = args[5]; + + put_task_stack(target); + return 0; +} + +/** + * task_current_syscall - Discover what a blocked task is doing. + * @target: thread to examine + * @info: structure with the following fields: + * .sp - filled with user stack pointer + * .data.nr - filled with system call number or -1 + * .data.args - filled with @maxargs system call arguments + * .data.instruction_pointer - filled with user PC + * + * If @target is blocked in a system call, returns zero with @info.data.nr + * set to the call's number and @info.data.args filled in with its + * arguments. Registers not used for system call arguments may not be available + * and it is not kosher to use &struct user_regset calls while the system + * call is still in progress. Note we may get this result if @target + * has finished its system call but not yet returned to user mode, such + * as when it's stopped for signal handling or syscall exit tracing. + * + * If @target is blocked in the kernel during a fault or exception, + * returns zero with *@info.data.nr set to -1 and does not fill in + * @info.data.args. If so, it's now safe to examine @target using + * &struct user_regset get() calls as long as we're sure @target won't return + * to user mode. + * + * Returns -%EAGAIN if @target does not remain blocked. + */ +int task_current_syscall(struct task_struct *target, struct syscall_info *info) +{ + unsigned long ncsw; + unsigned int state; + + if (target == current) + return collect_syscall(target, info); + + state = READ_ONCE(target->__state); + if (unlikely(!state)) + return -EAGAIN; + + ncsw = wait_task_inactive(target, state); + if (unlikely(!ncsw) || + unlikely(collect_syscall(target, info)) || + unlikely(wait_task_inactive(target, state) != ncsw)) + return -EAGAIN; + + return 0; +} -- cgit v1.3.1