linux/arch/xtensa/include/asm/ptrace.h
Max Filippov 5b835d4cad xtensa: use XCHAL_NUM_AREGS as pt_regs::areg size
struct pt_regs is used to access both kernel and user exception frames.
User exception frames may contain up to XCHAL_NUM_AREG registers that
task creation and signal delivery code may access, but pt_regs::areg
array has only 16 entries that cover only the kernel exception frame.
This results in the following build error:

arch/xtensa/kernel/process.c: In function 'copy_thread':
arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above
           array bounds of 'long unsigned int[16]' [-Werror=array-bounds]
  262 |                                 put_user(regs->areg[caller_ars+1],

Change struct pt_regs::areg size to XCHAL_NUM_AREGS so that it covers
the whole user exception frame. Adjust task_pt_regs and drop additional
register copying code from copy_thread now that the whole user exception
stack frame is copied.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2022-03-07 12:02:54 -08:00

117 lines
3.2 KiB
C

/*
* include/asm-xtensa/ptrace.h
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_PTRACE_H
#define _XTENSA_PTRACE_H
#include <asm/kmem_layout.h>
#include <uapi/asm/ptrace.h>
/*
* Kernel stack
*
* +-----------------------+ -------- STACK_SIZE
* | register file | |
* +-----------------------+ |
* | struct pt_regs | |
* +-----------------------+ | ------ PT_REGS_OFFSET
* double : 16 bytes spill area : | ^
* excetion :- - - - - - - - - - - -: | |
* frame : struct pt_regs : | |
* :- - - - - - - - - - - -: | |
* | | | |
* | memory stack | | |
* | | | |
* ~ ~ ~ ~
* ~ ~ ~ ~
* | | | |
* | | | |
* +-----------------------+ | | --- STACK_BIAS
* | struct task_struct | | | ^
* current --> +-----------------------+ | | |
* | struct thread_info | | | |
* +-----------------------+ --------
*/
#define NO_SYSCALL (-1)
#ifndef __ASSEMBLY__
#include <asm/coprocessor.h>
#include <asm/core.h>
/*
* This struct defines the way the registers are stored on the
* kernel stack during a system call or other kernel entry.
*/
struct pt_regs {
unsigned long pc; /* 4 */
unsigned long ps; /* 8 */
unsigned long depc; /* 12 */
unsigned long exccause; /* 16 */
unsigned long excvaddr; /* 20 */
unsigned long debugcause; /* 24 */
unsigned long wmask; /* 28 */
unsigned long lbeg; /* 32 */
unsigned long lend; /* 36 */
unsigned long lcount; /* 40 */
unsigned long sar; /* 44 */
unsigned long windowbase; /* 48 */
unsigned long windowstart; /* 52 */
unsigned long syscall; /* 56 */
unsigned long icountlevel; /* 60 */
unsigned long scompare1; /* 64 */
unsigned long threadptr; /* 68 */
/* Additional configurable registers that are used by the compiler. */
xtregs_opt_t xtregs_opt;
/* Make sure the areg field is 16 bytes aligned. */
int align[0] __attribute__ ((aligned(16)));
/* current register frame.
* Note: The ESF for kernel exceptions ends after 16 registers!
*/
unsigned long areg[XCHAL_NUM_AREGS];
};
# define arch_has_single_step() (1)
# define task_pt_regs(tsk) ((struct pt_regs*) \
(task_stack_page(tsk) + KERNEL_STACK_SIZE) - 1)
# define user_mode(regs) (((regs)->ps & 0x00000020)!=0)
# define instruction_pointer(regs) ((regs)->pc)
# define return_pointer(regs) (MAKE_PC_FROM_RA((regs)->areg[0], \
(regs)->areg[1]))
# ifndef CONFIG_SMP
# define profile_pc(regs) instruction_pointer(regs)
# else
# define profile_pc(regs) \
({ \
in_lock_functions(instruction_pointer(regs)) ? \
return_pointer(regs) : instruction_pointer(regs); \
})
# endif
#define user_stack_pointer(regs) ((regs)->areg[1])
static inline unsigned long regs_return_value(struct pt_regs *regs)
{
return regs->areg[2];
}
#else /* __ASSEMBLY__ */
# include <asm/asm-offsets.h>
#define PT_REGS_OFFSET (KERNEL_STACK_SIZE - PT_USER_SIZE)
#endif /* !__ASSEMBLY__ */
#endif /* _XTENSA_PTRACE_H */