88a7c26af8
On x86_64, at least, task_pt_regs may be only partially initialized in many contexts, so x86_64 should not use it without extra care from interrupt context, let alone NMI context. This will allow x86_64 to override the logic and will supply some scratch space to use to make a cleaner copy of user regs. Tested-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: chenggang.qcg@taobao.com Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jean Pihet <jean.pihet@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salter <msalter@redhat.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/perf_event.h>
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#include <linux/bug.h>
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#include <asm/compat.h>
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#include <asm/perf_regs.h>
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#include <asm/ptrace.h>
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u64 perf_reg_value(struct pt_regs *regs, int idx)
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{
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if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
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return 0;
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/*
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* Compat (i.e. 32 bit) mode:
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* - PC has been set in the pt_regs struct in kernel_entry,
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* - Handle SP and LR here.
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*/
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if (compat_user_mode(regs)) {
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if ((u32)idx == PERF_REG_ARM64_SP)
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return regs->compat_sp;
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if ((u32)idx == PERF_REG_ARM64_LR)
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return regs->compat_lr;
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}
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if ((u32)idx == PERF_REG_ARM64_SP)
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return regs->sp;
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if ((u32)idx == PERF_REG_ARM64_PC)
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return regs->pc;
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return regs->regs[idx];
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}
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#define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
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int perf_reg_validate(u64 mask)
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{
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if (!mask || mask & REG_RESERVED)
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return -EINVAL;
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return 0;
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}
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u64 perf_reg_abi(struct task_struct *task)
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{
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if (is_compat_thread(task_thread_info(task)))
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return PERF_SAMPLE_REGS_ABI_32;
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else
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return PERF_SAMPLE_REGS_ABI_64;
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}
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void perf_get_regs_user(struct perf_regs *regs_user,
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struct pt_regs *regs,
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struct pt_regs *regs_user_copy)
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{
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regs_user->regs = task_pt_regs(current);
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regs_user->abi = perf_reg_abi(current);
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}
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