Jordan Niethe's on March 20, 2020 3:18 pm:
> Prefixed instructions will mean there are instructions of different
> length. As a result dereferencing a pointer to an instruction will not
> necessarily give the desired result. Introduce a function for reading
> instructions from memory into the instruction data type.
>
> Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> ---
> v4: New to series
> ---
> arch/powerpc/include/asm/uprobes.h | 4 ++--
> arch/powerpc/kernel/kprobes.c | 8 ++++----
> arch/powerpc/kernel/mce_power.c | 2 +-
> arch/powerpc/kernel/optprobes.c | 6 +++---
> arch/powerpc/kernel/trace/ftrace.c | 33 +++++++++++++++++++-----------
> arch/powerpc/kernel/uprobes.c | 2 +-
> arch/powerpc/lib/code-patching.c | 22 ++++++++++----------
> arch/powerpc/lib/feature-fixups.c | 6 +++---
> arch/powerpc/xmon/xmon.c | 6 +++---
> 9 files changed, 49 insertions(+), 40 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/uprobes.h
> b/arch/powerpc/include/asm/uprobes.h
> index 2bbdf27d09b5..fff3c5fc90b5 100644
> --- a/arch/powerpc/include/asm/uprobes.h
> +++ b/arch/powerpc/include/asm/uprobes.h
> @@ -23,8 +23,8 @@ typedef ppc_opcode_t uprobe_opcode_t;
>
> struct arch_uprobe {
> union {
> - u32 insn;
> - u32 ixol;
> + u8 insn[MAX_UINSN_BYTES];
> + u8 ixol[MAX_UINSN_BYTES];
> };
> };
Hmm. I wonder if this should be a different patch. Not sure if raw
bytes is a good idea here. ppc probes also has a ppc_opcode_t, maybe
could be replaced with ppc_insn_t and used here instead?
Also can't find where you define ppc_inst_read.
> diff --git a/arch/powerpc/kernel/trace/ftrace.c
> b/arch/powerpc/kernel/trace/ftrace.c
> index 7614a9f537fd..ad451205f268 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -41,6 +41,12 @@
> #define NUM_FTRACE_TRAMPS 8
> static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
>
> +static long
> +read_inst(ppc_inst *inst, const void *src)
> +{
> + return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE);
> +}
Humbly suggest probe_kernel_inst_read.
Thanks,
Nick
