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author | Thomas Gleixner <tglx@linutronix.de> | 2019-11-11 23:03:21 +0100 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2019-11-16 11:24:02 +0100 |
commit | 577d5cd7e5851d3832066cd0422475fa7db2ee17 (patch) | |
tree | 1de44238f0b2b0db2cb4778fc374f73cb8fe69f2 | |
parent | f5848e5fd2f813c3a8009a642dfbcf635287c199 (diff) | |
download | linux-stable-577d5cd7e5851d3832066cd0422475fa7db2ee17.tar.gz linux-stable-577d5cd7e5851d3832066cd0422475fa7db2ee17.tar.bz2 linux-stable-577d5cd7e5851d3832066cd0422475fa7db2ee17.zip |
x86/ioperm: Move iobitmap data into a struct
No point in having all the data in thread_struct, especially as upcoming
changes add more.
Make the bitmap in the new struct accessible as array of longs and as array
of characters via a union, so both the bitmap functions and the update
logic can avoid type casts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r-- | arch/x86/include/asm/io_bitmap.h | 13 | ||||
-rw-r--r-- | arch/x86/include/asm/processor.h | 6 | ||||
-rw-r--r-- | arch/x86/kernel/ioport.c | 27 | ||||
-rw-r--r-- | arch/x86/kernel/process.c | 38 | ||||
-rw-r--r-- | arch/x86/kernel/ptrace.c | 12 |
5 files changed, 57 insertions, 39 deletions
diff --git a/arch/x86/include/asm/io_bitmap.h b/arch/x86/include/asm/io_bitmap.h new file mode 100644 index 000000000000..1a12b9ff5e4e --- /dev/null +++ b/arch/x86/include/asm/io_bitmap.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_IOBITMAP_H +#define _ASM_X86_IOBITMAP_H + +#include <asm/processor.h> + +struct io_bitmap { + /* The maximum number of bytes to copy so all zero bits are covered */ + unsigned int max; + unsigned long bitmap[IO_BITMAP_LONGS]; +}; + +#endif diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index cd7cd7d10b81..c949e0e5cbe6 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -7,6 +7,7 @@ /* Forward declaration, a strange C thing */ struct task_struct; struct mm_struct; +struct io_bitmap; struct vm86; #include <asm/math_emu.h> @@ -501,10 +502,8 @@ struct thread_struct { struct vm86 *vm86; #endif /* IO permissions: */ - unsigned long *io_bitmap_ptr; + struct io_bitmap *io_bitmap; unsigned long iopl; - /* Max allowed port in the bitmap, in bytes: */ - unsigned io_bitmap_max; mm_segment_t addr_limit; @@ -862,7 +861,6 @@ static inline void spin_lock_prefetch(const void *x) #define INIT_THREAD { \ .sp0 = TOP_OF_INIT_STACK, \ .sysenter_cs = __KERNEL_CS, \ - .io_bitmap_ptr = NULL, \ .addr_limit = KERNEL_DS, \ } diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index 80d99bb826f3..05f77f3af46d 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -11,6 +11,7 @@ #include <linux/sched.h> #include <linux/slab.h> +#include <asm/io_bitmap.h> #include <asm/desc.h> /* @@ -21,7 +22,7 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) unsigned int i, max_long, bytes, bytes_updated; struct thread_struct *t = ¤t->thread; struct tss_struct *tss; - unsigned long *bitmap; + struct io_bitmap *iobm; if ((from + num <= from) || (from + num > IO_BITMAP_BITS)) return -EINVAL; @@ -34,16 +35,16 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) * IO bitmap up. ioperm() is much less timing critical than clone(), * this is why we delay this operation until now: */ - bitmap = t->io_bitmap_ptr; - if (!bitmap) { + iobm = t->io_bitmap; + if (!iobm) { /* No point to allocate a bitmap just to clear permissions */ if (!turn_on) return 0; - bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); - if (!bitmap) + iobm = kmalloc(sizeof(*iobm), GFP_KERNEL); + if (!iobm) return -ENOMEM; - memset(bitmap, 0xff, IO_BITMAP_BYTES); + memset(iobm->bitmap, 0xff, sizeof(iobm->bitmap)); } /* @@ -52,9 +53,9 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) */ preempt_disable(); if (turn_on) - bitmap_clear(bitmap, from, num); + bitmap_clear(iobm->bitmap, from, num); else - bitmap_set(bitmap, from, num); + bitmap_set(iobm->bitmap, from, num); /* * Search for a (possibly new) maximum. This is simple and stupid, @@ -62,26 +63,26 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) */ max_long = 0; for (i = 0; i < IO_BITMAP_LONGS; i++) { - if (bitmap[i] != ~0UL) + if (iobm->bitmap[i] != ~0UL) max_long = i; } bytes = (max_long + 1) * sizeof(unsigned long); - bytes_updated = max(bytes, t->io_bitmap_max); + bytes_updated = max(bytes, t->io_bitmap->max); /* Update the thread data */ - t->io_bitmap_max = bytes; + iobm->max = bytes; /* * Store the bitmap pointer (might be the same if the task already * head one). Set the TIF flag, just in case this is the first * invocation. */ - t->io_bitmap_ptr = bitmap; + t->io_bitmap = iobm; set_thread_flag(TIF_IO_BITMAP); /* Update the TSS */ tss = this_cpu_ptr(&cpu_tss_rw); - memcpy(tss->io_bitmap.bitmap, t->io_bitmap_ptr, bytes_updated); + memcpy(tss->io_bitmap.bitmap, iobm->bitmap, bytes_updated); /* Store the new end of the zero bits */ tss->io_bitmap.prev_max = bytes; /* Make the bitmap base in the TSS valid */ diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 35f1c80df7a8..1504fd2b9bc4 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -41,6 +41,7 @@ #include <asm/desc.h> #include <asm/prctl.h> #include <asm/spec-ctrl.h> +#include <asm/io_bitmap.h> #include <asm/proto.h> #include "process.h" @@ -101,21 +102,20 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) void exit_thread(struct task_struct *tsk) { struct thread_struct *t = &tsk->thread; - unsigned long *bp = t->io_bitmap_ptr; + struct io_bitmap *iobm = t->io_bitmap; struct fpu *fpu = &t->fpu; struct tss_struct *tss; - if (bp) { + if (iobm) { preempt_disable(); tss = this_cpu_ptr(&cpu_tss_rw); - t->io_bitmap_ptr = NULL; - t->io_bitmap_max = 0; + t->io_bitmap = NULL; clear_thread_flag(TIF_IO_BITMAP); /* Invalidate the io bitmap base in the TSS */ tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID; preempt_enable(); - kfree(bp); + kfree(iobm); } free_vm86(t); @@ -135,25 +135,25 @@ static int set_new_tls(struct task_struct *p, unsigned long tls) static inline int copy_io_bitmap(struct task_struct *tsk) { + struct io_bitmap *iobm = current->thread.io_bitmap; + if (likely(!test_tsk_thread_flag(current, TIF_IO_BITMAP))) return 0; - tsk->thread.io_bitmap_ptr = kmemdup(current->thread.io_bitmap_ptr, - IO_BITMAP_BYTES, GFP_KERNEL); - if (!tsk->thread.io_bitmap_ptr) { - tsk->thread.io_bitmap_max = 0; + tsk->thread.io_bitmap = kmemdup(iobm, sizeof(*iobm), GFP_KERNEL); + + if (!tsk->thread.io_bitmap) return -ENOMEM; - } + set_tsk_thread_flag(tsk, TIF_IO_BITMAP); return 0; } static inline void free_io_bitmap(struct task_struct *tsk) { - if (tsk->thread.io_bitmap_ptr) { - kfree(tsk->thread.io_bitmap_ptr); - tsk->thread.io_bitmap_ptr = NULL; - tsk->thread.io_bitmap_max = 0; + if (tsk->thread.io_bitmap) { + kfree(tsk->thread.io_bitmap); + tsk->thread.io_bitmap = NULL; } } @@ -172,7 +172,7 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp, frame->bp = 0; frame->ret_addr = (unsigned long) ret_from_fork; p->thread.sp = (unsigned long) fork_frame; - p->thread.io_bitmap_ptr = NULL; + p->thread.io_bitmap = NULL; memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); #ifdef CONFIG_X86_64 @@ -366,6 +366,8 @@ static inline void switch_to_bitmap(struct thread_struct *next, struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); if (tifn & _TIF_IO_BITMAP) { + struct io_bitmap *iobm = next->io_bitmap; + /* * Copy at least the size of the incoming tasks bitmap * which covers the last permitted I/O port. @@ -374,11 +376,11 @@ static inline void switch_to_bitmap(struct thread_struct *next, * bits permitted, then the copy needs to cover those as * well so they get turned off. */ - memcpy(tss->io_bitmap.bitmap, next->io_bitmap_ptr, - max(tss->io_bitmap.prev_max, next->io_bitmap_max)); + memcpy(tss->io_bitmap.bitmap, next->io_bitmap->bitmap, + max(tss->io_bitmap.prev_max, next->io_bitmap->max)); /* Store the new max and set io_bitmap_base valid */ - tss->io_bitmap.prev_max = next->io_bitmap_max; + tss->io_bitmap.prev_max = next->io_bitmap->max; tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_VALID; /* diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 7c526741215b..066e5b01a7e0 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -42,6 +42,7 @@ #include <asm/traps.h> #include <asm/syscall.h> #include <asm/fsgsbase.h> +#include <asm/io_bitmap.h> #include "tls.h" @@ -697,7 +698,9 @@ static int ptrace_set_debugreg(struct task_struct *tsk, int n, static int ioperm_active(struct task_struct *target, const struct user_regset *regset) { - return DIV_ROUND_UP(target->thread.io_bitmap_max, regset->size); + struct io_bitmap *iobm = target->thread.io_bitmap; + + return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0; } static int ioperm_get(struct task_struct *target, @@ -705,12 +708,13 @@ static int ioperm_get(struct task_struct *target, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { - if (!target->thread.io_bitmap_ptr) + struct io_bitmap *iobm = target->thread.io_bitmap; + + if (!iobm) return -ENXIO; return user_regset_copyout(&pos, &count, &kbuf, &ubuf, - target->thread.io_bitmap_ptr, - 0, IO_BITMAP_BYTES); + iobm->bitmap, 0, IO_BITMAP_BYTES); } /* |