[PATCH v5 00/10] powerpc64/ftrace: Add support for ftrace_modify_call() and a few other fixes

works properly on a Power8 machine. More details in the patch. All other patches are unchanged from v4. - Naveen Naveen N. Rao (10): powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths powerpc64/ftrace: Rearrange #ifdef sections in ftrace.h powerpc64/ftrace: Add

Re: [PATCH] powerpc64s: Print exception vector name alongside the trap number

Benjamin Herrenschmidt wrote: On Wed, 2018-04-18 at 14:32 +0530, Naveen N. Rao wrote: +#ifdef CONFIG_PPC_BOOK3S_64 +static char *print_trap(unsigned long trapno) +{ + trapno &= 0xff0; + switch (trapno) { + case 0x100: return "SRESET"; +

[PATCH] powerpc64s: Print exception vector name alongside the trap number

: 90009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 2822 XER: 2000 CFAR: c06e4770 DAR: DSISR: 4200 SOFTE: 0 Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- I find this useful to have in backtraces, instead of having to look it up. Some

Re: [PATCH 1/2] KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode

Michael Ellerman wrote: Nicholas Piggin writes: On Sun, 8 Apr 2018 20:17:47 +1000 Balbir Singh wrote: On Fri, Apr 6, 2018 at 3:56 AM, Nicholas Piggin wrote: > This crashes with a "Bad real address for load" attempting to load >

[PATCH] selftests/powerpc: add test to verify rfi flush across a system call

as when it is disabled. Signed-off-by: Anton Blanchard <an...@samba.org> Signed-off-by: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- tools/testing/selftests/powerpc/Makefile | 3 +- tools/testing/selftes

[PATCH] powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it

CPU_FTR_DAWR enabled. Guard __set_breakpoint() within hw_breakpoint_disable() with ppc_breakpoint_available() to address this. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/hw_breakpoint.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff

[PATCH v4 10/10] powerpc64/ftrace: Implement support for ftrace_regs_caller()

implementation for ftrace_caller() that is used when registers are not required to be saved. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 2 - arch/powerpc/include/asm/module.h | 3 + arch/powerpc/

[PATCH v4 09/10] powerpc64/ftrace: Use the generic version of ftrace_replace_code()

Our implementation matches that of the generic version, which also handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in favor of the generic version. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/trace/ftrace.

[PATCH v4 08/10] powerpc64/module: Tighten detection of mcount call sites with -mprofile-kernel

ies as early. Fixes: 153086644fd1f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/module_64.c | 15 +-- 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/ar

[PATCH v4 07/10] powerpc64/kexec: Hard disable ftrace before switching to the new kernel

during kexec. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/machine_kexec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index 2694d078741d..936c7e2d421e 100644 ---

[PATCH v4 06/10] powerpc64/ftrace: Disable ftrace during hotplug

Disable ftrace when a cpu is about to go offline. When the cpu is woken up, ftrace will get enabled in start_secondary(). Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/smp.c | 8 1 file changed, 8 insertions(+) diff --git a/arch/powerpc/

[PATCH v4 05/10] powerpc64/ftrace: Delay enabling ftrace on secondary cpus

ondary() for secondary cpus. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/setup_64.c | 10 +++--- arch/powerpc/kernel/smp.c | 4 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kerne

[PATCH v4 04/10] powerpc64/ftrace: Add helpers to hard disable ftrace

Add some helpers to enable/disable ftrace through paca->ftrace_enabled. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 17 + 1 file changed, 17 insertions(+) diff --git a/arch/powerpc/include/asm/ftrace.h b/arc

[PATCH v4 03/10] powerpc64/ftrace: Rearrange #ifdef sections in ftrace.h

Re-arrange the last #ifdef section in preparation for a subsequent change. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 8 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/ftrace.h

[PATCH v4 02/10] powerpc64/ftrace: Disable ftrace during kvm guest entry/exit

ftrace by setting paca->ftrace_enabled to zero. Once we exit the guest and restore host MMU context, we re-enable ftrace. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 1 file changed, 8 insertions(+) diff --git a/arc

[PATCH v4 01/10] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

uses a 'trap' to do its job. For such scenarios, introduce a new field in paca 'ftrace_enabled', which is checked on ftrace entry before continuing. This field can then be set to zero to disable/pause ftrace, and set to a non-zero value to resume ftrace. Signed-off-by: Naveen N. Rao <navee

[PATCH v4 00/10] powerpc64/ftrace: Add support for ftrace_modify_call() and a few other fixes

new implementation of ftrace_caller() that saves the minimum register state is provided. We switch between the two variants through ftrace_modify_call(). The necessary support to call into the two different variants from modules is also added. - Naveen Naveen N. Rao (10): powerpc64/ftrace:

Re: [PATCH v3 3/6] powerpc/kexec: Disable ftrace before switching to the new kernel

Michael Ellerman wrote: Michael Ellerman <m...@ellerman.id.au> writes: "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> writes: If function_graph tracer is enabled during kexec, we see the below exception in the simulator: root@(none):/# kexec -e

[PATCH v3 5/6] powerpc64/ftrace: Use the generic version of ftrace_replace_code()

Our implementation matches that of the generic version, which also handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in favor of the generic version. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/trace/ftrace.

[PATCH v3 6/6] powerpc64/ftrace: Implement support for ftrace_regs_caller()

implementation for ftrace_caller() that is used when registers are not required to be saved. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- Changes since v2: - Disable ftrace when asked for, in ftrace_caller(). arch/powerpc/include/asm/ftrace.h | 2 -

[PATCH v3 4/6] powerpc64/module: Tighten detection of mcount call sites with -mprofile-kernel

ies as early. Fixes: 153086644fd1f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/module_64.c | 15 +-- 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/ar

[PATCH v3 3/6] powerpc/kexec: Disable ftrace before switching to the new kernel

-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/machine_kexec.c | 6 ++ 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index 2694d078741d..4a1b24a9dd61 100644 --- a/arch/p

[PATCH v3 2/6] powerpc64/ftrace: Disable ftrace during kvm guest entry/exit

ftrace by setting paca->ftrace_disabled. Once we exit the guest and restore host MMU context, we re-enable ftrace. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 1 file changed, 8 insertions(+) diff --git a/arch/po

[PATCH v3 1/6] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

ost...@goodmis.org> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- Changes since v2: - Move paca->ftrace_disabled out of CONFIG_BOOK3S_64. - Disable tracing when asked for, not the other way around. arch/powerpc/include/asm/paca.h| 1 + arch/pow

[PATCH v3 0/6] powerpc64/ftrace: Add support for ftrace_modify_call() and a few other fixes

different variants from modules is also added. - Naveen Naveen N. Rao (6): powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths powerpc64/ftrace: Disable ftrace during kvm guest entry/exit powerpc/kexec: Disable ftrace before switching to the new kernel powerpc64

Re: [PATCH v2 1/5] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Naveen N. Rao wrote: We have some C code that we call into from real mode where we cannot take any exceptions. Though the C functions themselves are mostly safe, if these functions are traced, there is a possibility that we may take an exception. For instance, in certain conditions, the ftrace

Re: [PATCH v2 5/5] powerpc64/ftrace: Implement support for ftrace_regs_caller()

Steven Rostedt wrote: On Wed, 21 Mar 2018 20:59:03 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: Thanks for the review! You're welcome. Note, I did put "Acked-by" and not "Reviewed-by" because my "Reviewed-by" is usually a bit

Re: [PATCH v2 5/5] powerpc64/ftrace: Implement support for ftrace_regs_caller()

Steven Rostedt wrote: On Wed, 21 Mar 2018 20:07:32 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: I think that will always be set here. ftrace_64_mprofile.S is only built for -mprofile-kernel and we select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL is e

Re: [PATCH v2 5/5] powerpc64/ftrace: Implement support for ftrace_regs_caller()

Steven Rostedt wrote: On Wed, 21 Mar 2018 16:13:22 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs) { mod->arch.toc = my_r2(sechdrs, mod); - mod->arch.tramp = create_ft

[PATCH v2 1/5] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

uses a 'trap' to do its job. For such scenarios, introduce a new field in paca 'ftrace_disabled', which is checked on ftrace entry before continuing. This field can then be set to a non-zero value to disable/pause ftrace, and reset to zero to resume ftrace. Signed-off-by: Naveen N. Rao <navee

[PATCH v2 2/5] powerpc64/ftrace: Disable ftrace during kvm guest entry/exit

ftrace by setting paca->ftrace_disabled. Once we exit the guest and restore host MMU context, we re-enable ftrace. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 1 file changed, 8 insertions(+) diff --git a/arch/po

[PATCH v2 5/5] powerpc64/ftrace: Implement support for ftrace_regs_caller()

implementation for ftrace_caller() that is used when registers are not required to be saved. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 2 - arch/powerpc/include/asm/module.h | 3 + arch/powerpc/

[PATCH v2 4/5] powerpc64/ftrace: Use the generic version of ftrace_replace_code()

Our implementation matches that of the generic version, which also handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in favor of the generic version. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/trace/ftrace.

[PATCH v2 3/5] powerpc64/module: Tighten detection of mcount call sites with -mprofile-kernel

ies as early. Fixes: 153086644fd1f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/module_64.c | 15 +-- 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/ar

[PATCH v2 0/5] powerpc/ftrace: Add support for ftrace_modify_call() and a few other fixes

register state is provided. We switch between the two variants through ftrace_modify_call(). The necessary support to call into the two different variants from modules is also added. - Naveen Naveen N. Rao (5): powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Re: [PATCH 1/2] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Michael Ellerman wrote: Nicholas Piggin <npig...@gmail.com> writes: On Mon, 19 Mar 2018 14:43:00 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: We have some C code that we call into from real mode where we cannot take any exceptions. Though the

Re: [PATCH 1/2] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Steven Rostedt wrote: On Mon, 19 Mar 2018 14:43:00 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index 3f3e81852422..fdf702b4df25 100644 --- a/arc

Re: [PATCH 1/2] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Nicholas Piggin wrote: On Mon, 19 Mar 2018 14:43:00 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: We have some C code that we call into from real mode where we cannot take any exceptions. Though the C functions themselves are mostly safe, if these func

[PATCH 2/2] powerpc64/ftrace: Disable ftrace during kvm guest entry/exit

ftrace by setting paca->ftrace_disabled. Once we exit the guest and restore host MMU context, we re-enable ftrace. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 1 file changed, 8 insertions(+) diff --git a/arch/po

[PATCH 1/2] powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

for this currently, we guard the ftrace/mcount checks within CONFIG_KVM. This can later be removed if/when there are other users. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/paca.h| 1 + arch/powerpc/kernel/asm-offsets.c | 1 +

[PATCH 0/2] Disable ftrace during kvm guest entry/exit

and as such, it is guarded in CONFIG_KVM as suggested by Steven Rostedt. This has had some minimal testing, and I will continue to test it this week and report back if I see any issues. - Naveen Naveen N. Rao (2): powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths

Re: [RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

Michael Ellerman wrote: "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> writes: My earlier assumption was that we have other scenarios when we are in realmode (specifically with MSR_RI unset) where we won't be able to recover from a trap, during function tracing

Re: [RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

Steven Rostedt wrote: On Thu, 08 Mar 2018 00:07:07 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: Yes, that's negligible. Though, to be honest, I will have to introduce a 'mfmsr' for the older -pg variant. I still think that the improved reliability far outw

Re: [RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

Michael Ellerman wrote: "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> writes: We can't take a trap in most parts of real mode code. Instead of adding the 'notrace' annotation to all C functions that can be invoked from real mode, detect that we are in real mode on ftrace

Re: [RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

Hi Steve, Steven Rostedt wrote: On Wed, 7 Mar 2018 22:16:19 +0530 "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: We can't take a trap in most parts of real mode code. Instead of adding the 'notrace' annotation to all C functions that can be invoked from real mode

[RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

We can't take a trap in most parts of real mode code. Instead of adding the 'notrace' annotation to all C functions that can be invoked from real mode, detect that we are in real mode on ftrace entry and return back. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- This RF

[RFC PATCH 0/1] Exclude real mode code from ftrace

ofile-kernel, and would need to be updated to deal with other ftrace entry code. Naveen N. Rao (1): powerpc/ftrace: Exclude real mode code from being traced arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 15 +++ 1 file changed, 15 insertions(+) -- 2.16.1

Re: [PATCH 2/2] powerpc/perf: Fix the kernel address leak to userspace via SDAR

Madhavan Srinivasan wrote: Sampled Data Address Register (SDAR) is a 64-bit register that contains the effective address of the storage operand of an instruction that was being executed, possibly out-of-order, at or around the time that the Performance Monitor alert occurred. In certain

Re: [PATCH AUTOSEL for 4.9 005/219] kretprobes: Ensure probe location is at function entry

Hi Sasha, Sasha Levin wrote: From: "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> [ Upstream commit 90ec5e89e393c76e19afc845d8f88a5dc8315919 ] Sorry if this is obvious, but why was this patch picked up for -stable? I don't see the upstream commit tagging -stable

Re: [RFC][PATCH bpf] tools: bpftool: Fix tags for bpf-to-bpf calls

Daniel Borkmann wrote: On 02/27/2018 01:13 PM, Sandipan Das wrote: With this patch, it will look like this: 0: (85) call pc+2#bpf_prog_8f85936f29a7790a+3 (Note the +2 is the insn->off already.) 1: (b7) r0 = 1 2: (95) exit 3: (b7) r0 = 2 4: (95) exit where 8f85936f29a7790a is

Re: [PATCH] bpf, powerpc: fix jit for seccomp_data access

Mark Lord wrote: On 18-02-21 07:52 AM, Mark Lord wrote: On 18-02-21 03:35 AM, Naveen N. Rao wrote: .. Looks good to me, but I am not able to apply this patch. There seems to be whitespace damage. Here (attached) is a clean copy. Again, this time with the commit message included! Thanks

Re: [PATCH] bpf, powerpc: fix jit for seccomp_data access

Mark Lord wrote: I am using SECCOMP to filter syscalls on a ppc32 platform, and noticed that the JIT compiler was failing on the BPF even though the interpreter was working fine. The issue was that the compiler was missing one of the instructions used by SECCOMP, so here is a patch to enable

Re: [RFC][PATCH bpf v2 1/2] bpf: allow 64-bit offsets for bpf function calls

Michael Ellerman wrote: "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> writes: Daniel Borkmann wrote: On 02/15/2018 05:25 PM, Daniel Borkmann wrote: On 02/13/2018 05:05 AM, Sandipan Das wrote: The imm field of a bpf_insn is a signed 32-bit integer. For JIT-ed bpf-to-bp

Re: [RFC][PATCH bpf v2 1/2] bpf: allow 64-bit offsets for bpf function calls

Daniel Borkmann wrote: On 02/15/2018 05:25 PM, Daniel Borkmann wrote: On 02/13/2018 05:05 AM, Sandipan Das wrote: The imm field of a bpf_insn is a signed 32-bit integer. For JIT-ed bpf-to-bpf function calls, it stores the offset from __bpf_call_base to the start of the callee function. For

Re: [RFC][PATCH bpf 1/2] bpf: allow 64-bit offsets for bpf function calls

Naveen N. Rao wrote: Alexei Starovoitov wrote: On 2/8/18 4:03 AM, Sandipan Das wrote: The imm field of a bpf_insn is a signed 32-bit integer. For JIT-ed bpf-to-bpf function calls, it stores the offset from __bpf_call_base to the start of the callee function. For some architectures

Re: [RFC][PATCH bpf 1/2] bpf: allow 64-bit offsets for bpf function calls

Alexei Starovoitov wrote: On 2/8/18 4:03 AM, Sandipan Das wrote: The imm field of a bpf_insn is a signed 32-bit integer. For JIT-ed bpf-to-bpf function calls, it stores the offset from __bpf_call_base to the start of the callee function. For some architectures, such as powerpc64, it was found

Re: [PATCH] powerpc/kprobes: Fix call trace due to incorrect preempt count

Michael Ellerman wrote: Ananth N Mavinakayanahalli <ana...@linux.vnet.ibm.com> writes: On Wed, Jan 17, 2018 at 05:52:24PM +0530, Naveen N. Rao wrote: Michael Ellerman reported the following call trace when running ftracetest: BUG: using __this_cpu_write() in preemptible [

[PATCH] powerpc/kprobes: Fix call trace due to incorrect preempt count

ing preemption and resetting current kprobe to the probe handlers (kprobe_handler() or optimized_callback()). Reported-by: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kprobes.c | 30 +--

Re: [PATCH] powerpc/perf: Dereference bhrb entries safely

] perf_event_interrupt+0x298/0x460 [c0027964] performance_monitor_exception+0x54/0x70 [c0009ba4] performance_monitor_common+0x114/0x120 Fix this by deferefencing them safely. Suggested-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> Signed-off-by: Ravi Bangoria <r

Re: [PATCH] powernv: Avoid calling trace tlbie in kexec path.

Michael Ellerman wrote: Balbir Singh writes: On Thu, Nov 23, 2017 at 4:32 AM, Mahesh J Salgaonkar wrote: From: Mahesh Salgaonkar Rebooting into a new kernel with kexec fails in trace_tlbie() which is called from

Re: [PATCH] powernv: Avoid calling trace tlbie in kexec path.

Mahesh Jagannath Salgaonkar wrote: On 11/23/2017 12:37 AM, Naveen N. Rao wrote: Mahesh J Salgaonkar wrote: From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com> Rebooting into a new kernel with kexec fails in trace_tlbie() which is called from native_hpte_clear(). This happens if the r

Re: [PATCH] powernv: Avoid calling trace tlbie in kexec path.

Mahesh J Salgaonkar wrote: From: Mahesh Salgaonkar Rebooting into a new kernel with kexec fails in trace_tlbie() which is called from native_hpte_clear(). This happens if the running kernel has CONFIG_LOCKDEP enabled. With lockdep enabled, the tracepoints always

Re: [PATCH v4.2] powerpc/modules: Don't try to restore r2 after a sibling call

Kamalesh Babulal wrote: On Thursday 16 November 2017 11:15 PM, Josh Poimboeuf wrote: On Thu, Nov 16, 2017 at 06:39:03PM +0530, Naveen N. Rao wrote: Josh Poimboeuf wrote: On Wed, Nov 15, 2017 at 02:58:33PM +0530, Naveen N. Rao wrote: +int instr_is_link_branch(unsigned int instr

Re: [PATCH v4 2/3] powerpc/modules: Don't try to restore r2 after a sibling call

Josh Poimboeuf wrote: On Wed, Nov 15, 2017 at 02:58:33PM +0530, Naveen N. Rao wrote: > +int instr_is_link_branch(unsigned int instr) > +{ > + return (instr_is_branch_iform(instr) || instr_is_branch_bform(instr)) && > + (instr & BRANCH_SET_LINK); > +} >

Re: [PATCH v4 2/3] powerpc/modules: Don't try to restore r2 after a sibling call

Josh Poimboeuf wrote: On Tue, Nov 14, 2017 at 03:59:21PM +0530, Naveen N. Rao wrote: Kamalesh Babulal wrote: > From: Josh Poimboeuf <jpoim...@redhat.com> > > When attempting to load a livepatch module, I got the following error: > > module_64: patch_module: Expect noo

Re: [PATCH v4 2/3] powerpc/modules: Don't try to restore r2 after a sibling call

Kamalesh Babulal wrote: From: Josh Poimboeuf When attempting to load a livepatch module, I got the following error: module_64: patch_module: Expect noop after relocate, got 3c82 The error was triggered by the following code in unregister_netdevice_queue(): 14c:

Re: [PATCH v2] powerpc64/exceptions: Refactor code to eliminate a few memory loads

Michael Ellerman wrote: > "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> writes: > >> On 2017/06/19 03:21PM, Aneesh Kumar K.V wrote: >>> > @@ -1445,8 +1446,8 @@ do_hash_page: >>> > handle_page_fault: >>> > andis. r0,r4,DSISR_

Re: [PATCH v3] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

Josh Poimboeuf wrote: On Tue, Nov 07, 2017 at 12:31:05PM +0100, Torsten Duwe wrote: On Tue, Nov 07, 2017 at 07:34:29PM +1100, Michael Ellerman wrote: > > So, just brainstorming a bit, here are the possible solutions I can > > think of: > > > > a) Create a special klp stub for such calls (as in

Re: [PATCH v3] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

On 2017/10/31 03:30PM, Torsten Duwe wrote: > On Tue, Oct 31, 2017 at 07:49:59PM +0530, Naveen N . Rao wrote: > > Hi Kamalesh, > > Sorry for the late review. Overall, the patch looks good to me. > > If you're good with a hammer... > > Maybe I failed to express my views

Re: [PATCH v3] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

Hi Kamalesh, Sorry for the late review. Overall, the patch looks good to me. So: Acked-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> However, I have a few minor comments which can be addressed in a subsequent patch. On 2017/10/17 05:18AM, Kamalesh Babulal wrote: > Livepatch re-us

[PATCH 2/2] powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text

it needed to be dereferenced. This is actually only an issue for kprobe blacklisted asm labels (through use of _ASM_NOKPROBE_SYMBOL) and can cause other issues with ftrace. Also, the additional checks are not really necessary for our other uses. As such, move this check to the kprobes subsystem. Signed-off-by

[PATCH 1/2] Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols"

a recursive loop. Reported-by: Chandan Rajendra <chan...@linux.vnet.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/include/asm/code-patching.h | 10 +- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/arch/powerpc/include/asm/cod

[PATCH 0/2] Fix function_graph tracer for ppc64 BE

in ppc_function_entry() for all users. - Naveen Naveen N. Rao (2): Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols" powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text arch/powerpc/includ

Re: [PATCH 4/4] powerpc/kprobes: refactor kprobe_lookup_name for safer string operations

On 2017/10/25 04:35PM, Masami Hiramatsu wrote: > On Mon, 23 Oct 2017 22:07:41 +0530 > "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: > > > Use safer string manipulation functions when dealing with a > > user-provided string in kprobe_lookup_name().

Re: [PATCH 1/4] powerpc/kprobes: Disable preemption before invoking probe handler for optprobes

On 2017/10/25 02:18AM, Masami Hiramatsu wrote: > On Mon, 23 Oct 2017 22:07:38 +0530 > "Naveen N. Rao" <naveen.n@linux.vnet.ibm.com> wrote: > > > Per Documentation/kprobes.txt, probe handlers need to be invoked with > > preemption disabled. Update opt

[PATCH 4/4] powerpc/kprobes: refactor kprobe_lookup_name for safer string operations

Use safer string manipulation functions when dealing with a user-provided string in kprobe_lookup_name(). Reported-by: David Laight <david.lai...@aculab.com> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kp

[PATCH 3/4] powerpc/kprobes: Blacklist emulate_update_regs() from kprobes

Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/lib/sstep.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 8c3955e183d4..70274b7b4773 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/ss

[PATCH 2/4] powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace

Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kprobes-ftrace.c | 10 ++ arch/powerpc/kernel/optprobes.c | 10 -- 2 files changed, 2 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerp

[PATCH 1/4] powerpc/kprobes: Disable preemption before invoking probe handler for optprobes

if CONFIG_PREEMPT was enabled. Commit a30b85df7d599f ("kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT=y") changes this. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/optprobes.c | 5 +++-- 1 file changed, 3 insertions(+), 2 de

Re: [PATCH v5] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

pendency for registers that are not used for > CLOCK_REALTIME_COARSE (Naveen) > - Reorder instructions to get proper dependency setup (Naveen) > > arch/powerpc/kernel/asm-offsets.c | 2 + > arch/powerpc/kernel/vdso64/gettimeofday.S | 68 > ++- > 2 files changed, 59 insertions(+), 11 deletions(-) Looks good to me. Reviewed-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com>

Re: [PATCH v6] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

Hi Santosh, This seems to have gone from v4 to v6 -- did I miss v5? On 2017/10/10 11:10PM, Santosh Sivaraj wrote: > Current vDSO64 implementation does not have support for coarse clocks > (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back > to system call, increasing the

Re: [PATCH v4] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

On 2017/10/10 09:03AM, Santosh Sivaraj wrote: > * Naveen N. Rao <naveen.n@linux.vnet.ibm.com> wrote (on 2017-10-09 > 10:39:18 +): > > > On 2017/10/09 08:09AM, Santosh Sivaraj wrote: [snip] > > > + add r3,r3,r0 > > > + ld r0,CFG_TB_UPD

Re: [PATCH v2] powerpc/lib/sstep: Fix count leading zeros instructions

nge analyse_instr so it doesn't modify > *regs") > Signed-off-by: Sandipan Das <sandi...@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> > --- > v2: Make zero-checking condition more compact. > Add details of original commit that

Re: [PATCH] powerpc/lib/sstep: Fix count leading zeros instructions

On 2017/10/09 11:07AM, Sandipan Das wrote: > According to the GCC documentation, the behaviour of __builtin_clz() > and __builtin_clzl() is undefined if the value of the input argument > is zero. Without handling this special case, these builtins have been > used for emulating the following

Re: [PATCH v4] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

On 2017/10/09 08:09AM, Santosh Sivaraj wrote: > Current vDSO64 implementation does not have support for coarse clocks > (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back > to system call, increasing the response time, vDSO implementation reduces > the cycle time. Below is a

Re: [PATCH 2/2] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

On 2017/09/18 09:23AM, Santosh Sivaraj wrote: > Current vDSO64 implementation does not have support for coarse clocks > (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back > to system call, increasing the response time, vDSO implementation reduces > the cycle time. Below is a

Re: [PATCH 2/2] powerpc/vdso64: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE

On 2017/09/18 09:23AM, Santosh Sivaraj wrote: > Current vDSO64 implementation does not have support for coarse clocks > (CLOCK_MONOTONIC_COARSE, CLOCK_REALTIME_COARSE), for which it falls back > to system call, increasing the response time, vDSO implementation reduces > the cycle time. Below is a

Re: [PATCH 1/2] powerpc/vdso64: Coarse timer support preparatory patch

Hi Santosh, On 2017/09/18 09:23AM, Santosh Sivaraj wrote: > Reorganize code to make it easy to introduce CLOCK_REALTIME_COARSE and > CLOCK_MONOTONIC_COARSE timer support. > > Signed-off-by: Santosh Sivaraj > --- > arch/powerpc/kernel/vdso64/gettimeofday.S | 14

Re: [PATCH v2] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

egular stack and is used to store/restore TOC/LR values, other than > the stub setup and branch. The additional instructions sequences to > handle klp_stub increases the stub size and current ppc64_stub_insn[] > is not sufficient to hold them. This patch also introduces new > ppc6

Re: [PATCH] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

ues, other than > the stub setup and branch. The additional instructions sequences to handle > klp_stub increases the stub size and current ppc64_stub_insn[] is not > sufficient to hold them. This patch also introduces new > ppc64le_klp_stub_entry[], along with the helpers to find/allocate > livep

Re: [PATCH 1/3] powerpc/lib/sstep: Add XER bits introduced in POWER ISA v3.0

n behaviour of all these instructions needs to > be updated to set these new bits accordingly. > > Signed-off-by: Sandipan Das <sandi...@linux.vnet.ibm.com> For this series: Acked-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> > --- > arch/powerpc/lib/sstep.c | 2 ++ >

[PATCH v2 6/6] powerpc/jprobes: Validate break handler invocation as being due to a jprobe_return()

Fix a circa 2005 FIXME by implementing a check to ensure that we actually got into the jprobe break handler() due to the trap in jprobe_return(). Acked-by: Masami Hiramatsu <mhira...@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kp

[PATCH v2 5/6] powerpc/jprobes: Disable preemption when triggered through ftrace

dler(). Disable it. Fixes: ead514d5fb30a0 ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE") Acked-by: Masami Hiramatsu <mhira...@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kprobes-ftrace.c | 15 +++

[PATCH v2 3/6] powerpc/kprobes: Clean up jprobe detection in livepatch handler

patch renames is_current_kprobe_addr() to __is_active_jprobe() and adds a comment to (hopefully) better clarify the purpose of this helper. The helper has also now been moved to kprobes-ftrace.c so that it is only available for KPROBES_ON_FTRACE. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ib

[PATCH v2 4/6] powerpc/kprobes: Fix warnings from __this_cpu_read() on preempt kernels

check done by __this_cpu_read(). Fixes: c05b8c4474c030 ("powerpc/kprobes: Skip livepatch_handler() for jprobes") Reported-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com> Tested-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n@li

[PATCH v2 1/6] powerpc/kprobes: Some cosmetic updates to try_to_emulate()

1. This is only used in kprobes.c, so make it static. 2. Remove the un-necessary (ret == 0) comparison in the else clause. Reviewed-by: Masami Hiramatsu <mhira...@kernel.org> Reviewed-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n@lin

[PATCH v2 2/6] powerpc/kprobes: Do not suppress instruction emulation if a single run failed

at least once, then we single step only this probe hit and continue to try emulating the instruction in subsequent probe hits. Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> --- arch/powerpc/kernel/kprobes.c | 17 ++--- 1 file changed, 14 insertions(+), 3 del

[PATCH v2 0/6] powerpc/kprobes: More fixes

detection of jprobe in ftrace_caller() and that this is only for KPROBES_ON_FTRACE. - Naveen Naveen N. Rao (6): powerpc/kprobes: Some cosmetic updates to try_to_emulate() powerpc/kprobes: Do not suppress instruction emulation if a single run failed powerpc/kprobes: Clean up jprobe

Re: [PATCH] powerpc/livepatch: Fix livepatch stack access

On 2017/09/21 09:00PM, Balbir Singh wrote: > On Thu, Sep 21, 2017 at 8:02 PM, Michael Ellerman wrote: > > Kamalesh Babulal writes: > > > >> While running stress test with livepatch module loaded, kernel > >> bug was triggered. > >> > >> cpu 0x5:

Re: [PATCH] powerpc/livepatch: Fix livepatch stack access

g task stack and livepatch stack into r1 register. > Using r11 register also avoids disabling/enabling irq's while setting > up the livepatch stack. > > Signed-off-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com> > Cc: Balbir Singh <bsinghar...@gmail.com> > Cc: Naveen N. Rao &

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