From e859d375d1694488015e6804bfeea527a0b25b9f Mon Sep 17 00:00:00 2001 From: Wojtek Wasko Date: Mon, 3 Mar 2025 18:13:43 +0200 Subject: [PATCH] posix-clock: Store file pointer in struct posix_clock_context File descriptor based pc_clock_*() operations of dynamic posix clocks have access to the file pointer and implement permission checks in the generic code before invoking the relevant dynamic clock callback. Character device operations (open, read, poll, ioctl) do not implement a generic permission control and the dynamic clock callbacks have no access to the file pointer to implement them. Extend struct posix_clock_context with a struct file pointer and initialize it in posix_clock_open(), so that all dynamic clock callbacks can access it. Acked-by: Richard Cochran Reviewed-by: Vadim Fedorenko Reviewed-by: Thomas Gleixner Signed-off-by: Wojtek Wasko Signed-off-by: David S. Miller --- include/linux/posix-clock.h | 6 +++++- kernel/time/posix-clock.c | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/posix-clock.h b/include/linux/posix-clock.h index ef8619f48920..a500d3160fe8 100644 --- a/include/linux/posix-clock.h +++ b/include/linux/posix-clock.h @@ -95,10 +95,13 @@ struct posix_clock { * struct posix_clock_context - represents clock file operations context * * @clk: Pointer to the clock + * @fp: Pointer to the file used to open the clock * @private_clkdata: Pointer to user data * * Drivers should use struct posix_clock_context during specific character - * device file operation methods to access the posix clock. + * device file operation methods to access the posix clock. In particular, + * the file pointer can be used to verify correct access mode for ioctl() + * calls. * * Drivers can store a private data structure during the open operation * if they have specific information that is required in other file @@ -106,6 +109,7 @@ struct posix_clock { */ struct posix_clock_context { struct posix_clock *clk; + struct file *fp; void *private_clkdata; }; diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c index 1af0bb2cc45c..4e114e34a6e0 100644 --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -129,6 +129,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp) goto out; } pccontext->clk = clk; + pccontext->fp = fp; if (clk->ops.open) { err = clk->ops.open(pccontext, fp->f_mode); if (err) { -- 2.50.1