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author | Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | 2017-11-08 07:30:15 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-11-16 15:06:14 +0100 |
commit | 0da0017f72554c005c1a04c3adc5da9eb64fa7e5 (patch) | |
tree | caca91b7cc8c47786c3c617c7a311c7e4f4bd1a0 /arch/s390/kernel/perf_regs.c | |
parent | a9fc2db0a8abf51c81122799c5ae4808f2324b6d (diff) | |
download | linux-0da0017f72554c005c1a04c3adc5da9eb64fa7e5.tar.bz2 |
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: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/perf_regs.c')
-rw-r--r-- | arch/s390/kernel/perf_regs.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_regs.c b/arch/s390/kernel/perf_regs.c index e883e6a2146a..f8603ebed669 100644 --- a/arch/s390/kernel/perf_regs.c +++ b/arch/s390/kernel/perf_regs.c @@ -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); } |