Commit-ID: 32caa06091cc59651222cdc971dc21eaab36b097 Gitweb: http://git.kernel.org/tip/32caa06091cc59651222cdc971dc21eaab36b097 Author: Denys Vlasenko <[email protected]> AuthorDate: Fri, 10 Apr 2015 15:06:58 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Sat, 11 Apr 2015 13:08:53 +0200
perf/x86/64: Simplify regs_user->abi setting code in get_regs_user() user_64bit_mode(regs) basically checks regs->cs to point to a 64-bit segment. This check used to be unreliable here because regs->cs was not always correct in syscalls. Now regs->cs is always correct: in syscalls, in interrupts, in exceptions. No need to emply heuristics here. Signed-off-by: Denys Vlasenko <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/perf_regs.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c index a8d4e48..8157d39 100644 --- a/arch/x86/kernel/perf_regs.c +++ b/arch/x86/kernel/perf_regs.c @@ -166,22 +166,8 @@ void perf_get_regs_user(struct perf_regs *regs_user, * be careful not to look at any other percpu variables that might * change during context switches. */ - if (IS_ENABLED(CONFIG_IA32_EMULATION) && - task_thread_info(current)->status & TS_COMPAT) { - /* Easy case: we're in a compat syscall. */ - regs_user->abi = PERF_SAMPLE_REGS_ABI_32; - } else if (user_regs->orig_ax != -1) { - /* - * We're probably in a 64-bit syscall. - * Warning: this code is severely racy. At least it's better - * than just blindly copying user_regs. - */ - regs_user->abi = PERF_SAMPLE_REGS_ABI_64; - } else { - /* We're probably in an interrupt or exception. */ - regs_user->abi = user_64bit_mode(user_regs) ? - PERF_SAMPLE_REGS_ABI_64 : PERF_SAMPLE_REGS_ABI_32; - } + regs_user->abi = user_64bit_mode(user_regs) ? + PERF_SAMPLE_REGS_ABI_64 : PERF_SAMPLE_REGS_ABI_32; regs_user->regs = regs_user_copy; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
