From: Alistair Popple <alistair@popple•id.au>
To: Jordan Niethe <jniethe5@gmail•com>
Cc: npiggin@gmail•com, bala24@linux•ibm.com,
naveen.n.rao@linux•vnet.ibm.com, linuxppc-dev@lists•ozlabs.org,
dja@axtens•net
Subject: Re: [PATCH v7 17/28] powerpc: Introduce a function for reporting instruction length
Date: Tue, 05 May 2020 12:02:59 +1000 [thread overview]
Message-ID: <3087823.8VYvvlUQXN@townsend> (raw)
In-Reply-To: <20200501034220.8982-18-jniethe5@gmail.com>
Looks good,
Reviewed-by: Alistair Popple <alistair@popple•id.au>
On Friday, 1 May 2020 1:42:09 PM AEST Jordan Niethe wrote:
> Currently all instructions have the same length, but in preparation for
> prefixed instructions introduce a function for returning instruction
> length.
>
> Signed-off-by: Jordan Niethe <jniethe5@gmail•com>
> ---
> v6: - feature-fixups.c: do_final_fixups(): use here
> - ppc_inst_len(): change return type from bool to int
> - uprobes: Use ppc_inst_read() before calling ppc_inst_len()
> ---
> arch/powerpc/include/asm/inst.h | 5 +++++
> arch/powerpc/kernel/kprobes.c | 6 ++++--
> arch/powerpc/kernel/uprobes.c | 2 +-
> arch/powerpc/lib/feature-fixups.c | 14 +++++++-------
> 4 files changed, 17 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/inst.h
> b/arch/powerpc/include/asm/inst.h index 0d581b332c20..2f3c9d5bcf7c 100644
> --- a/arch/powerpc/include/asm/inst.h
> +++ b/arch/powerpc/include/asm/inst.h
> @@ -17,6 +17,11 @@ static inline u32 ppc_inst_val(struct ppc_inst x)
> return x.val;
> }
>
> +static inline int ppc_inst_len(struct ppc_inst x)
> +{
> + return sizeof(struct ppc_inst);
> +}
> +
> static inline int ppc_inst_primary_opcode(struct ppc_inst x)
> {
> return ppc_inst_val(x) >> 26;
> diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
> index a72c8e1a42ad..33d54b091c70 100644
> --- a/arch/powerpc/kernel/kprobes.c
> +++ b/arch/powerpc/kernel/kprobes.c
> @@ -462,14 +462,16 @@ NOKPROBE_SYMBOL(trampoline_probe_handler);
> */
> int kprobe_post_handler(struct pt_regs *regs)
> {
> + int len;
> struct kprobe *cur = kprobe_running();
> struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
>
> if (!cur || user_mode(regs))
> return 0;
>
> + len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn));
> /* make sure we got here for instruction we have a kprobe on */
> - if (((unsigned long)cur->ainsn.insn + 4) != regs->nip)
> + if (((unsigned long)cur->ainsn.insn + len) != regs->nip)
> return 0;
>
> if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
> @@ -478,7 +480,7 @@ int kprobe_post_handler(struct pt_regs *regs)
> }
>
> /* Adjust nip to after the single-stepped instruction */
> - regs->nip = (unsigned long)cur->addr + 4;
> + regs->nip = (unsigned long)cur->addr + len;
> regs->msr |= kcb->kprobe_saved_msr;
>
> /*Restore back the original saved kprobes variables and continue. */
> diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c
> index 6893d40a48c5..83e883e1a42d 100644
> --- a/arch/powerpc/kernel/uprobes.c
> +++ b/arch/powerpc/kernel/uprobes.c
> @@ -112,7 +112,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe,
> struct pt_regs *regs) * support doesn't exist and have to fix-up the next
> instruction * to be executed.
> */
> - regs->nip = utask->vaddr + MAX_UINSN_BYTES;
> + regs->nip = utask->vaddr + ppc_inst_len(ppc_inst_read(&auprobe->insn));
>
> user_disable_single_step(current);
> return 0;
> diff --git a/arch/powerpc/lib/feature-fixups.c
> b/arch/powerpc/lib/feature-fixups.c index 13ec3264a565..f4845e740338 100644
> --- a/arch/powerpc/lib/feature-fixups.c
> +++ b/arch/powerpc/lib/feature-fixups.c
> @@ -390,20 +390,20 @@ void do_lwsync_fixups(unsigned long value, void
> *fixup_start, void *fixup_end) static void do_final_fixups(void)
> {
> #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
> - struct ppc_inst *src, *dest;
> - unsigned long length;
> + struct ppc_inst inst, *src, *dest, *end;
>
> if (PHYSICAL_START == 0)
> return;
>
> src = (struct ppc_inst *)(KERNELBASE + PHYSICAL_START);
> dest = (struct ppc_inst *)KERNELBASE;
> - length = (__end_interrupts - _stext) / sizeof(struct ppc_inst);
> + end = (void *)src + (__end_interrupts - _stext);
>
> - while (length--) {
> - raw_patch_instruction(dest, ppc_inst_read(src));
> - src++;
> - dest++;
> + while (src < end) {
> + inst = ppc_inst_read(src);
> + raw_patch_instruction(dest, inst);
> + src = (void *)src + ppc_inst_len(inst);
> + dest = (void *)dest + ppc_inst_len(inst);
> }
> #endif
> }
next prev parent reply other threads:[~2020-05-05 2:04 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 3:41 [PATCH v7 00/28] Initial Prefixed Instruction support Jordan Niethe
2020-05-01 3:41 ` [PATCH v7 01/28] powerpc/xmon: Remove store_inst() for patch_instruction() Jordan Niethe
2020-05-01 3:41 ` [PATCH v7 02/28] powerpc/xmon: Move breakpoint instructions to own array Jordan Niethe
2020-05-04 5:41 ` Alistair Popple
2020-05-04 5:52 ` Jordan Niethe
2020-05-01 3:41 ` [PATCH v7 03/28] powerpc/xmon: Move breakpoints to text section Jordan Niethe
2020-05-01 3:41 ` [PATCH v7 04/28] powerpc/xmon: Use bitwise calculations in_breakpoint_table() Jordan Niethe
2020-05-04 5:41 ` Alistair Popple
2020-05-05 7:08 ` Michael Ellerman
2020-05-05 7:31 ` Jordan Niethe
2020-05-01 3:41 ` [PATCH v7 05/28] powerpc: Change calling convention for create_branch() et. al Jordan Niethe
2020-05-04 2:55 ` Alistair Popple
2020-05-01 3:41 ` [PATCH v7 06/28] powerpc: Use a macro for creating instructions from u32s Jordan Niethe
2020-05-04 5:54 ` Alistair Popple
2020-05-01 3:41 ` [PATCH v7 07/28] powerpc: Use an accessor for instructions Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 08/28] powerpc: Use a function for getting the instruction op code Jordan Niethe
2020-05-04 8:01 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 09/28] powerpc: Use a function for byte swapping instructions Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 10/28] powerpc: Introduce functions for instruction equality Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 11/28] powerpc: Use a datatype for instructions Jordan Niethe
2020-05-02 14:29 ` kbuild test robot
2020-05-01 3:42 ` [PATCH v7 12/28] powerpc: Use a function for reading instructions Jordan Niethe
2020-05-04 8:26 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 13/28] powerpc: Add a probe_user_read_inst() function Jordan Niethe
2020-05-04 8:30 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 14/28] powerpc: Add a probe_kernel_read_inst() function Jordan Niethe
2020-05-04 9:24 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 15/28] powerpc/kprobes: Use patch_instruction() Jordan Niethe
2020-05-05 1:41 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 16/28] powerpc: Define and use __get_user_instr{, inatomic}() Jordan Niethe
2020-05-05 1:46 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 17/28] powerpc: Introduce a function for reporting instruction length Jordan Niethe
2020-05-05 2:02 ` Alistair Popple [this message]
2020-05-01 3:42 ` [PATCH v7 18/28] powerpc/xmon: Use a function for reading instructions Jordan Niethe
2020-05-05 2:07 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 19/28] powerpc/xmon: Move insertion of breakpoint for xol'ing Jordan Niethe
2020-05-05 2:19 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 20/28] powerpc: Make test_translate_branch() independent of instruction length Jordan Niethe
2020-05-05 2:40 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 21/28] powerpc: Enable Prefixed Instructions Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 22/28] powerpc: Define new SRR1 bits for a future ISA version Jordan Niethe
2020-05-05 2:49 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 23/28] powerpc: Add prefixed instructions to instruction data type Jordan Niethe
2020-05-05 6:04 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 24/28] powerpc: Test prefixed code patching Jordan Niethe
2020-05-05 6:08 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 25/28] powerpc: Test prefixed instructions in feature fixups Jordan Niethe
2020-05-05 7:15 ` Alistair Popple
2020-05-05 7:34 ` Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 26/28] powerpc: Support prefixed instructions in alignment handler Jordan Niethe
2020-05-05 7:17 ` Alistair Popple
2020-05-01 3:42 ` [PATCH v7 27/28] powerpc sstep: Add support for prefixed load/stores Jordan Niethe
2020-05-01 3:42 ` [PATCH v7 28/28] powerpc sstep: Add support for prefixed fixed-point arithmetic Jordan Niethe
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