On Fri, Oct 18, 2013 at 03:54:37PM +0100, Jean Pihet wrote:
From: Jean Pihet jean.pihet@newoldbits.com
This patch implements the functions required for the perf registers API, allowing the perf tool to interface kernel register dumps with libunwind in order to provide userspace backtracing. Only the general purpose user space registers are exported, i.e.: PERF_REG_ARM_X0, ... PERF_REG_ARM_X28, PERF_REG_ARM_FP, PERF_REG_ARM_LR, PERF_REG_ARM_SP, PERF_REG_ARM_PC and not the PERF_REG_ARM_V* registers.
[...]
diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c new file mode 100644 index 0000000..bbcf63c --- /dev/null +++ b/arch/arm64/kernel/perf_regs.c @@ -0,0 +1,29 @@ +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/perf_event.h> +#include <linux/bug.h> +#include <asm/perf_regs.h> +#include <asm/ptrace.h>
+u64 perf_reg_value(struct pt_regs *regs, int idx) +{
- if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM_MAX))
return 0;- return regs->regs[idx];
+}
+#define REG_RESERVED (~((1ULL << PERF_REG_ARM_MAX) - 1))
+int perf_reg_validate(u64 mask) +{
- if (!mask || mask & REG_RESERVED)
return -EINVAL;- return 0;
+}
+u64 perf_reg_abi(struct task_struct *task) +{
- return PERF_SAMPLE_REGS_ABI_64;
+}
You need to deal with compat (AArch32) tasks here too, which means providing something compatible with what we do on arch/arm/ depending on the thread flags.
Will