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Commit 0da0017f authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
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s390/perf: extend perf_regs support to include floating-point registers 



Extend the perf register support to also export floating-point register
contents for user space tasks.  Floating-point registers might be used
in leaf functions to contain the return address.  Hence, they are required
for proper DWARF unwinding.

Signed-off-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: default avatarThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent a9fc2db0

arch/s390/include/uapi/asm/perf_regs.h

+16 −0
Original line number Diff line number Diff line
@@ -18,6 +18,22 @@ enum perf_event_s390_regs { 
	PERF_REG_S390_R13,

	PERF_REG_S390_R14,

	PERF_REG_S390_R15,

	PERF_REG_S390_FP0,

	PERF_REG_S390_FP1,

	PERF_REG_S390_FP2,

	PERF_REG_S390_FP3,

	PERF_REG_S390_FP4,

	PERF_REG_S390_FP5,

	PERF_REG_S390_FP6,

	PERF_REG_S390_FP7,

	PERF_REG_S390_FP8,

	PERF_REG_S390_FP9,

	PERF_REG_S390_FP10,

	PERF_REG_S390_FP11,

	PERF_REG_S390_FP12,

	PERF_REG_S390_FP13,

	PERF_REG_S390_FP14,

	PERF_REG_S390_FP15,

	PERF_REG_S390_MASK,

	PERF_REG_S390_PC,

arch/s390/kernel/perf_regs.c

+21 −0
Original line number Diff line number Diff line
@@ -4,12 +4,29 @@ 
#include <linux/errno.h>

#include <linux/bug.h>

#include <asm/ptrace.h>

#include <asm/fpu/api.h>

#include <asm/fpu/types.h>



u64 perf_reg_value(struct pt_regs *regs, int idx)

{

	freg_t fp;



	if (WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX))

		return 0;



	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)

		return regs->gprs[idx];



	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {

		if (!user_mode(regs))

			return 0;



		idx -= PERF_REG_S390_FP0;

		fp = MACHINE_HAS_VX ? *(freg_t *)(current->thread.fpu.vxrs + idx)

				    : current->thread.fpu.fprs[idx];

		return fp.ui;

	}



	if (idx == PERF_REG_S390_MASK)

		return regs->psw.mask;

	if (idx == PERF_REG_S390_PC)
@@ -43,7 +60,11 @@ void perf_get_regs_user(struct perf_regs *regs_user, 
	/*

	 * Use the regs from the first interruption and let

	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).

	 *

	 * Also save FPU registers for user-space tasks only.

	 */

	regs_user->regs = task_pt_regs(current);

	if (user_mode(regs_user->regs))

		save_fpu_regs();

	regs_user->abi = perf_reg_abi(current);

}