xref: /openbmc/linux/arch/arm64/kernel/perf_regs.c (revision 68db0cf10678630d286f4bbbbdfa102951a35faa)
12ee0d7fdSJean Pihet #include <linux/errno.h>
22ee0d7fdSJean Pihet #include <linux/kernel.h>
32ee0d7fdSJean Pihet #include <linux/perf_event.h>
42ee0d7fdSJean Pihet #include <linux/bug.h>
5*68db0cf1SIngo Molnar #include <linux/sched/task_stack.h>
6ff268ff7SMark Salter 
7ff268ff7SMark Salter #include <asm/compat.h>
82ee0d7fdSJean Pihet #include <asm/perf_regs.h>
92ee0d7fdSJean Pihet #include <asm/ptrace.h>
102ee0d7fdSJean Pihet 
112ee0d7fdSJean Pihet u64 perf_reg_value(struct pt_regs *regs, int idx)
122ee0d7fdSJean Pihet {
132ee0d7fdSJean Pihet 	if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
142ee0d7fdSJean Pihet 		return 0;
152ee0d7fdSJean Pihet 
162ee0d7fdSJean Pihet 	/*
172ee0d7fdSJean Pihet 	 * Compat (i.e. 32 bit) mode:
182ee0d7fdSJean Pihet 	 * - PC has been set in the pt_regs struct in kernel_entry,
192ee0d7fdSJean Pihet 	 * - Handle SP and LR here.
202ee0d7fdSJean Pihet 	 */
212ee0d7fdSJean Pihet 	if (compat_user_mode(regs)) {
222ee0d7fdSJean Pihet 		if ((u32)idx == PERF_REG_ARM64_SP)
232ee0d7fdSJean Pihet 			return regs->compat_sp;
242ee0d7fdSJean Pihet 		if ((u32)idx == PERF_REG_ARM64_LR)
252ee0d7fdSJean Pihet 			return regs->compat_lr;
262ee0d7fdSJean Pihet 	}
272ee0d7fdSJean Pihet 
285b75a6afSWill Deacon 	if ((u32)idx == PERF_REG_ARM64_SP)
295b75a6afSWill Deacon 		return regs->sp;
305b75a6afSWill Deacon 
315b75a6afSWill Deacon 	if ((u32)idx == PERF_REG_ARM64_PC)
325b75a6afSWill Deacon 		return regs->pc;
335b75a6afSWill Deacon 
342ee0d7fdSJean Pihet 	return regs->regs[idx];
352ee0d7fdSJean Pihet }
362ee0d7fdSJean Pihet 
372ee0d7fdSJean Pihet #define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
382ee0d7fdSJean Pihet 
392ee0d7fdSJean Pihet int perf_reg_validate(u64 mask)
402ee0d7fdSJean Pihet {
412ee0d7fdSJean Pihet 	if (!mask || mask & REG_RESERVED)
422ee0d7fdSJean Pihet 		return -EINVAL;
432ee0d7fdSJean Pihet 
442ee0d7fdSJean Pihet 	return 0;
452ee0d7fdSJean Pihet }
462ee0d7fdSJean Pihet 
472ee0d7fdSJean Pihet u64 perf_reg_abi(struct task_struct *task)
482ee0d7fdSJean Pihet {
492ee0d7fdSJean Pihet 	if (is_compat_thread(task_thread_info(task)))
502ee0d7fdSJean Pihet 		return PERF_SAMPLE_REGS_ABI_32;
512ee0d7fdSJean Pihet 	else
522ee0d7fdSJean Pihet 		return PERF_SAMPLE_REGS_ABI_64;
532ee0d7fdSJean Pihet }
5488a7c26aSAndy Lutomirski 
5588a7c26aSAndy Lutomirski void perf_get_regs_user(struct perf_regs *regs_user,
5688a7c26aSAndy Lutomirski 			struct pt_regs *regs,
5788a7c26aSAndy Lutomirski 			struct pt_regs *regs_user_copy)
5888a7c26aSAndy Lutomirski {
5988a7c26aSAndy Lutomirski 	regs_user->regs = task_pt_regs(current);
6088a7c26aSAndy Lutomirski 	regs_user->abi = perf_reg_abi(current);
6188a7c26aSAndy Lutomirski }
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