From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Ingo Molnar <mingo@redhat.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Paul Mackerras <paulus@samba.org>,
Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64
Date: Mon, 18 Apr 2022 12:10:04 +0530 [thread overview]
Message-ID: <1650262952.h2adiu8czw.naveen@linux.ibm.com> (raw)
In-Reply-To: <fb60b19f154db8132a00c2df7aca7db3e85603b5.1648131740.git.christophe.leroy@csgroup.eu>
Christophe Leroy wrote:
> Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
> for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
> one for PPC64.
>
> Same for __ftrace_make_call().
>
> Make them common.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/kernel/trace/ftrace.c | 108 +++--------------------------
> 1 file changed, 8 insertions(+), 100 deletions(-)
>
> diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
> index 1b05d33f96c6..2c7e42e439bb 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -114,7 +114,6 @@ static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
> }
>
> #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
> static int
> __ftrace_make_nop(struct module *mod,
> struct dyn_ftrace *rec, unsigned long addr)
> @@ -154,10 +153,11 @@ __ftrace_make_nop(struct module *mod,
> return -EINVAL;
> }
>
> -#ifdef CONFIG_MPROFILE_KERNEL
> - /* When using -mkernel_profile there is no load to jump over */
> + /* When using -mkernel_profile or PPC32 there is no load to jump over */
-mprofile-kernel
Since you are modifying that line anyway ^^
> pop = ppc_inst(PPC_RAW_NOP());
>
> +#ifdef CONFIG_PPC64
> +#ifdef CONFIG_MPROFILE_KERNEL
> if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
> pr_err("Fetching instruction at %lx failed.\n", ip - 4);
> return -EFAULT;
> @@ -201,6 +201,7 @@ __ftrace_make_nop(struct module *mod,
> return -EINVAL;
> }
> #endif /* CONFIG_MPROFILE_KERNEL */
> +#endif /* PPC64 */
>
> if (patch_instruction((u32 *)ip, pop)) {
> pr_err("Patching NOP failed.\n");
> @@ -209,48 +210,6 @@ __ftrace_make_nop(struct module *mod,
>
> return 0;
> }
> -
> -#else /* !PPC64 */
> -static int
> -__ftrace_make_nop(struct module *mod,
> - struct dyn_ftrace *rec, unsigned long addr)
> -{
> - ppc_inst_t op;
> - unsigned long ip = rec->ip;
> - unsigned long tramp, ptr;
> -
> - if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE))
> - return -EFAULT;
> -
> - /* Make sure that that this is still a 24bit jump */
> - if (!is_bl_op(op)) {
> - pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));
> - return -EINVAL;
> - }
> -
> - /* lets find where the pointer goes */
> - tramp = find_bl_target(ip, op);
> -
> - /* Find where the trampoline jumps to */
> - if (module_trampoline_target(mod, tramp, &ptr)) {
> - pr_err("Failed to get trampoline target\n");
> - return -EFAULT;
> - }
> -
> - if (ptr != addr) {
> - pr_err("Trampoline location %08lx does not match addr\n",
> - tramp);
> - return -EINVAL;
> - }
> -
> - op = ppc_inst(PPC_RAW_NOP());
> -
> - if (patch_instruction((u32 *)ip, op))
> - return -EPERM;
> -
> - return 0;
> -}
> -#endif /* PPC64 */
> #endif /* CONFIG_MODULES */
>
> static unsigned long find_ftrace_tramp(unsigned long ip)
> @@ -437,13 +396,12 @@ int ftrace_make_nop(struct module *mod,
> }
>
> #ifdef CONFIG_MODULES
> -#ifdef CONFIG_PPC64
> /*
> * Examine the existing instructions for __ftrace_make_call.
> * They should effectively be a NOP, and follow formal constraints,
> * depending on the ABI. Return false if they don't.
> */
> -#ifndef CONFIG_MPROFILE_KERNEL
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
It is better to gate this on PPC64_ELF_ABI_v1
> static int
> expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
> {
> @@ -465,7 +423,7 @@ expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
> static int
> expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
> {
> - /* look for patched "NOP" on ppc64 with -mprofile-kernel */
> + /* look for patched "NOP" on ppc64 with -mprofile-kernel or ppc32 */
> if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
> return 0;
> return 1;
> @@ -484,8 +442,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
> if (copy_inst_from_kernel_nofault(op, ip))
> return -EFAULT;
>
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
> return -EFAULT;
> +#endif
Here too...
- Naveen
next prev parent reply other threads:[~2022-04-18 6:41 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-24 14:29 [PATCH v1 00/22] powerpc: ftrace optimisation and cleanup and more [v1] Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 01/22] powerpc/ftrace: Refactor prepare_ftrace_return() Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 02/22] powerpc/ftrace: Remove redundant create_branch() calls Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 03/22] powerpc/code-patching: Inline is_offset_in_{cond}_branch_range() Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 04/22] powerpc/ftrace: Use is_offset_in_branch_range() Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 05/22] powerpc/code-patching: Inline create_branch() Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code() Christophe Leroy
2022-04-18 6:07 ` Naveen N. Rao
2022-04-22 9:12 ` Michael Ellerman
2022-05-04 11:43 ` Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 07/22] powerpc/ftrace: Use patch_instruction() return directly Christophe Leroy
2022-04-18 6:21 ` Naveen N. Rao
2022-04-18 19:44 ` Steven Rostedt
2022-05-04 12:01 ` Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 08/22] powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 Christophe Leroy
2022-04-18 6:40 ` Naveen N. Rao [this message]
2022-05-04 12:19 ` Christophe Leroy
2022-05-06 11:41 ` Christophe Leroy
2022-03-24 14:29 ` [PATCH v1 09/22] powerpc/ftrace: Don't include ftrace.o for CONFIG_FTRACE_SYSCALLS Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 10/22] powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACE Christophe Leroy
2022-04-18 7:00 ` Naveen N. Rao
2022-05-06 11:41 ` Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 11/22] powerpc/ftrace: Remove ftrace_plt_tramps[] Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 12/22] powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1 Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 13/22] powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding Christophe Leroy
2022-04-18 7:38 ` Naveen N. Rao
2022-05-04 12:39 ` Christophe Leroy
2022-05-05 16:47 ` Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 14/22] powerpc/ftrace: Use size macro " Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 15/22] powerpc/ftrace: Simplify expected_nop_sequence() Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 16/22] powerpc/ftrace: Minimise number of #ifdefs Christophe Leroy
2022-04-18 7:59 ` Naveen N. Rao
2022-05-04 12:44 ` Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 17/22] powerpc/inst: Add __copy_inst_from_kernel_nofault() Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 18/22] powerpc/ftrace: Don't use copy_from_kernel_nofault() in module_trampoline_target() Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 19/22] powerpc/inst: Remove PPC_INST_BRANCH Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 20/22] powerpc/modules: Use PPC_INST_BRANCH_MASK instead of opencoding Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 21/22] powerpc/inst: Remove PPC_INST_BL Christophe Leroy
2022-03-24 14:30 ` [PATCH v1 22/22] powerpc/opcodes: Remove unused PPC_INST_XXX macros Christophe Leroy
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