Re: [PATCH] x86: fix a bug introduced by "allocate full pt_regs" commit
On Thu, Feb 26, 2015 at 6:08 AM, Denys Vlasenko wrote: > If syscall_trace_enter_phase1 returns 0, > code restores %rax from pt_regs->ax, but should restore it from > pt_regs->orig_ax. > > The bug crept in because LOAD_ARGS macro was very sublty different > from RESTORE_ARGS, it had only two callsites and only this one > was using that difference. I folded this in to the original patch to avoid breaking bisection. I put the missing -ARGOFFSET in and then removed it again in the appropriate place later in the series. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] x86: fix a bug introduced by "allocate full pt_regs" commit
If syscall_trace_enter_phase1 returns 0, code restores %rax from pt_regs->ax, but should restore it from pt_regs->orig_ax. The bug crept in because LOAD_ARGS macro was very sublty different from RESTORE_ARGS, it had only two callsites and only this one was using that difference. Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x...@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index da61974..519498d 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -316,7 +316,8 @@ tracesys: call syscall_trace_enter_phase1 test %rax, %rax jnz tracesys_phase2 /* if needed, run the slow path */ - RESTORE_C_REGS /* else restore clobbered regs */ + RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */ + movq ORIG_RAX(%rsp), %rax jmp system_call_fastpath/* and return to the fast path */ tracesys_phase2: -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] x86: fix a bug introduced by allocate full pt_regs commit
If syscall_trace_enter_phase1 returns 0, code restores %rax from pt_regs-ax, but should restore it from pt_regs-orig_ax. The bug crept in because LOAD_ARGS macro was very sublty different from RESTORE_ARGS, it had only two callsites and only this one was using that difference. Signed-off-by: Denys Vlasenko dvlas...@redhat.com CC: Linus Torvalds torva...@linux-foundation.org CC: Steven Rostedt rost...@goodmis.org CC: Ingo Molnar mi...@kernel.org CC: Borislav Petkov b...@alien8.de CC: H. Peter Anvin h...@zytor.com CC: Andy Lutomirski l...@amacapital.net CC: Oleg Nesterov o...@redhat.com CC: Frederic Weisbecker fweis...@gmail.com CC: Alexei Starovoitov a...@plumgrid.com CC: Will Drewry w...@chromium.org CC: Kees Cook keesc...@chromium.org CC: x...@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index da61974..519498d 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -316,7 +316,8 @@ tracesys: call syscall_trace_enter_phase1 test %rax, %rax jnz tracesys_phase2 /* if needed, run the slow path */ - RESTORE_C_REGS /* else restore clobbered regs */ + RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */ + movq ORIG_RAX(%rsp), %rax jmp system_call_fastpath/* and return to the fast path */ tracesys_phase2: -- 1.8.1.4 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] x86: fix a bug introduced by allocate full pt_regs commit
On Thu, Feb 26, 2015 at 6:08 AM, Denys Vlasenko dvlas...@redhat.com wrote: If syscall_trace_enter_phase1 returns 0, code restores %rax from pt_regs-ax, but should restore it from pt_regs-orig_ax. The bug crept in because LOAD_ARGS macro was very sublty different from RESTORE_ARGS, it had only two callsites and only this one was using that difference. I folded this in to the original patch to avoid breaking bisection. I put the missing -ARGOFFSET in and then removed it again in the appropriate place later in the series. --Andy -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
