From: Christophe Leroy Date: Mon, 9 May 2022 05:36:09 +0000 (+0200) Subject: powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 X-Git-Tag: v6.1-rc5~1222^2~62 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=23b44fc248f420bbcd0dcd290c3399885360984d;p=platform%2Fkernel%2Flinux-starfive.git powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/96f53c237316dab4b1b8c682685266faa92da816.1652074503.git.christophe.leroy@csgroup.eu --- diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 0b199fc9..531da4d 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 -mprofile-kernel or PPC32 there is no load to jump over */ 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 +#ifdef CONFIG_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; +#ifdef CONFIG_PPC64_ELF_ABI_V1 if (copy_inst_from_kernel_nofault(op + 1, ip + 4)) return -EFAULT; +#endif if (!expected_nop_sequence(ip, op[0], op[1])) { pr_err("Unexpected call sequence at %p: %s %s\n", @@ -531,58 +491,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return 0; } - -#else /* !CONFIG_PPC64: */ -static int -__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) -{ - int err; - ppc_inst_t op; - u32 *ip = (u32 *)rec->ip; - struct module *mod = rec->arch.mod; - unsigned long tramp; - - /* read where this goes */ - if (copy_inst_from_kernel_nofault(&op, ip)) - return -EFAULT; - - /* It should be pointing to a nop */ - if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_NOP()))) { - pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op)); - return -EINVAL; - } - - /* If we never set up a trampoline to ftrace_caller, then bail */ -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - if (!mod->arch.tramp || !mod->arch.tramp_regs) { -#else - if (!mod->arch.tramp) { -#endif - pr_err("No ftrace trampoline\n"); - return -EINVAL; - } - -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - if (rec->flags & FTRACE_FL_REGS) - tramp = mod->arch.tramp_regs; - else -#endif - tramp = mod->arch.tramp; - /* create the branch to the trampoline */ - err = create_branch(&op, ip, tramp, BRANCH_SET_LINK); - if (err) { - pr_err("REL24 out of range!\n"); - return -EINVAL; - } - - pr_devel("write to %lx\n", rec->ip); - - if (patch_instruction(ip, op)) - return -EPERM; - - return 0; -} -#endif /* CONFIG_PPC64 */ #endif /* CONFIG_MODULES */ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)