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[180.150.65.4]) by smtp.gmail.com with ESMTPSA id m2sm11460406pjk.4.2020.04.06.01.10.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Apr 2020 01:10:30 -0700 (PDT) From: Jordan Niethe To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v5 10/21] powerpc: Use a function for reading instructions Date: Mon, 6 Apr 2020 18:09:25 +1000 Message-Id: <20200406080936.7180-11-jniethe5@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200406080936.7180-1-jniethe5@gmail.com> References: <20200406080936.7180-1-jniethe5@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alistair@popple.id.au, npiggin@gmail.com, bala24@linux.ibm.com, Jordan Niethe , dja@axtens.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 --- v4: New to series v5: - Rename read_inst() -> probe_kernel_read_inst() - No longer modify uprobe probe type in this patch --- arch/powerpc/include/asm/inst.h | 5 +++++ arch/powerpc/kernel/kprobes.c | 11 ++++------ arch/powerpc/kernel/mce_power.c | 2 +- arch/powerpc/kernel/optprobes.c | 4 ++-- arch/powerpc/kernel/trace/ftrace.c | 33 +++++++++++++++++++----------- arch/powerpc/lib/code-patching.c | 23 ++++++++++----------- arch/powerpc/lib/feature-fixups.c | 2 +- arch/powerpc/xmon/xmon.c | 6 +++--- 8 files changed, 48 insertions(+), 38 deletions(-) diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h index a71decf5f871..369b35ce964c 100644 --- a/arch/powerpc/include/asm/inst.h +++ b/arch/powerpc/include/asm/inst.h @@ -27,6 +27,11 @@ static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x) return ppc_inst(swab32(ppc_inst_val(x))); } +static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr) +{ + return *ptr; +} + static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y) { return !memcmp(&x, &y, sizeof(struct ppc_inst)); diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 9ed996cb0589..ff53e5ef7e40 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -106,7 +106,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; - struct ppc_inst insn = *(struct ppc_inst *)p->addr; + struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr); if ((unsigned long)p->addr & 0x03) { printk("Attempt to register kprobe at an unaligned address\n"); @@ -125,11 +125,8 @@ int arch_prepare_kprobe(struct kprobe *p) } if (!ret) { - memcpy(p->ainsn.insn, p->addr, - MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); - p->opcode = *p->addr; - flush_icache_range((unsigned long)p->ainsn.insn, - (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); + patch_instruction((struct ppc_inst *)p->ainsn.insn, insn); + p->opcode = ppc_inst_val(insn); } p->ainsn.boostable = 0; @@ -217,7 +214,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe); static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) { int ret; - struct ppc_inst insn = *(struct ppc_inst *)p->ainsn.insn; + struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn); /* regs->nip is also adjusted if emulate_step returns 1 */ ret = emulate_step(regs, insn); diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c index 7118b46a6543..859b602fa270 100644 --- a/arch/powerpc/kernel/mce_power.c +++ b/arch/powerpc/kernel/mce_power.c @@ -374,7 +374,7 @@ static int mce_find_instr_ea_and_phys(struct pt_regs *regs, uint64_t *addr, pfn = addr_to_pfn(regs, regs->nip); if (pfn != ULONG_MAX) { instr_addr = (pfn << PAGE_SHIFT) + (regs->nip & ~PAGE_MASK); - instr = *(struct ppc_inst *)(instr_addr); + instr = ppc_inst_read((struct ppc_inst *)instr_addr); if (!analyse_instr(&op, &tmp, instr)) { pfn = addr_to_pfn(regs, op.ea); *addr = op.ea; diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index b61bbcee84f4..684640b8fa2e 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -100,8 +100,8 @@ static unsigned long can_optimize(struct kprobe *p) * Ensure that the instruction is not a conditional branch, * and that can be emulated. */ - if (!is_conditional_branch(*(struct ppc_inst *)p->ainsn.insn) && - analyse_instr(&op, ®s, *(struct ppc_inst *)p->ainsn.insn) == 1) { + if (!is_conditional_branch(ppc_inst_read((struct ppc_inst *)p->ainsn.insn)) && + analyse_instr(&op, ®s, ppc_inst_read((struct ppc_inst *)p->ainsn.insn)) == 1) { emulate_update_regs(®s, &op); nip = regs.nip; } diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 442c62fb68ff..e78742613b36 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 +probe_kernel_read_inst(struct ppc_inst *inst, const void *src) +{ + return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE); +} + static struct ppc_inst ftrace_call_replace(unsigned long ip, unsigned long addr, int link) { @@ -68,7 +74,7 @@ ftrace_modify_code(unsigned long ip, struct ppc_inst old, struct ppc_inst new) */ /* read the text we want to modify */ - if (probe_kernel_read(&replaced, (void *)ip, MCOUNT_INSN_SIZE)) + if (probe_kernel_read_inst(&replaced, (void *)ip)) return -EFAULT; /* Make sure it is what we expect it to be */ @@ -130,7 +136,7 @@ __ftrace_make_nop(struct module *mod, struct ppc_inst op, pop; /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { + if (probe_kernel_read_inst(&op, (void *)ip)) { pr_err("Fetching opcode failed.\n"); return -EFAULT; } @@ -164,7 +170,7 @@ __ftrace_make_nop(struct module *mod, /* When using -mkernel_profile there is no load to jump over */ pop = ppc_inst(PPC_INST_NOP); - if (probe_kernel_read(&op, (void *)(ip - 4), 4)) { + if (probe_kernel_read_inst(&op, (void *)(ip - 4))) { pr_err("Fetching instruction at %lx failed.\n", ip - 4); return -EFAULT; } @@ -196,7 +202,7 @@ __ftrace_make_nop(struct module *mod, * Check what is in the next instruction. We can see ld r2,40(r1), but * on first pass after boot we will see mflr r0. */ - if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) { + if (probe_kernel_read_inst(&op, (void *)(ip+4))) { pr_err("Fetching op failed.\n"); return -EFAULT; } @@ -348,7 +354,7 @@ static int setup_mcount_compiler_tramp(unsigned long tramp) return -1; /* New trampoline -- read where this goes */ - if (probe_kernel_read(&op, (void *)tramp, sizeof(int))) { + if (probe_kernel_read_inst(&op, (void *)tramp)) { pr_debug("Fetching opcode failed.\n"); return -1; } @@ -398,7 +404,7 @@ static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long addr) struct ppc_inst op; /* Read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { + if (probe_kernel_read_inst(&op, (void *)ip)) { pr_err("Fetching opcode failed.\n"); return -EFAULT; } @@ -524,7 +530,10 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) struct module *mod = rec->arch.mod; /* read where this goes */ - if (probe_kernel_read(op, ip, sizeof(op))) + if (probe_kernel_read_inst(op, ip)) + return -EFAULT; + + if (probe_kernel_read_inst(op + 1, ip + 4)) return -EFAULT; if (!expected_nop_sequence(ip, op[0], op[1])) { @@ -587,7 +596,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) unsigned long ip = rec->ip; /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE)) + if (probe_kernel_read_inst(&op, (void *)ip)) return -EFAULT; /* It should be pointing to a nop */ @@ -643,7 +652,7 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr) } /* Make sure we have a nop */ - if (probe_kernel_read(&op, ip, sizeof(op))) { + if (probe_kernel_read_inst(&op, ip)) { pr_err("Unable to read ftrace location %p\n", ip); return -EFAULT; } @@ -721,7 +730,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, } /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { + if (probe_kernel_read_inst(&op, (void *)ip)) { pr_err("Fetching opcode failed.\n"); return -EFAULT; } @@ -846,7 +855,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) struct ppc_inst old, new; int ret; - old = *(struct ppc_inst *)&ftrace_call; + old = ppc_inst_read((struct ppc_inst *)&ftrace_call); new = ftrace_call_replace(ip, (unsigned long)func, 1); ret = ftrace_modify_code(ip, old, new); @@ -854,7 +863,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) /* Also update the regs callback function */ if (!ret) { ip = (unsigned long)(&ftrace_regs_call); - old = *(struct ppc_inst *)&ftrace_regs_call; + old = ppc_inst_read((struct ppc_inst *)&ftrace_regs_call); new = ftrace_call_replace(ip, (unsigned long)func, 1); ret = ftrace_modify_code(ip, old, new); } diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 91be4a0b51cb..ba08f3815d00 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -349,9 +349,9 @@ static unsigned long branch_bform_target(const struct ppc_inst *instr) unsigned long branch_target(const struct ppc_inst *instr) { - if (instr_is_branch_iform(*instr)) + if (instr_is_branch_iform(ppc_inst_read(instr))) return branch_iform_target(instr); - else if (instr_is_branch_bform(*instr)) + else if (instr_is_branch_bform(ppc_inst_read(instr))) return branch_bform_target(instr); return 0; @@ -359,7 +359,7 @@ unsigned long branch_target(const struct ppc_inst *instr) int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr) { - if (instr_is_branch_iform(*instr) || instr_is_branch_bform(*instr)) + if (instr_is_branch_iform(ppc_inst_read(instr)) || instr_is_branch_bform(ppc_inst_read(instr))) return branch_target(instr) == addr; return 0; @@ -368,13 +368,12 @@ int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr) int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest, const struct ppc_inst *src) { unsigned long target; - target = branch_target(src); - if (instr_is_branch_iform(*src)) - return create_branch(instr, dest, target, ppc_inst_val(*src)); - else if (instr_is_branch_bform(*src)) - return create_cond_branch(instr, dest, target, ppc_inst_val(*src)); + if (instr_is_branch_iform(ppc_inst_read(src))) + return create_branch(instr, dest, target, ppc_inst_val(ppc_inst_read(src))); + else if (instr_is_branch_bform(ppc_inst_read(src))) + return create_cond_branch(instr, dest, target, ppc_inst_val(ppc_inst_read(src))); return 1; } @@ -598,7 +597,7 @@ static void __init test_translate_branch(void) patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); - check(ppc_inst_equal(*q, ppc_inst(0x4a000000))); + check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000))); /* Maximum positive case, move x to x - 32 MB + 4 */ p = buf + 0x2000000; @@ -609,7 +608,7 @@ static void __init test_translate_branch(void) patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); - check(ppc_inst_equal(*q, ppc_inst(0x49fffffc))); + check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc))); /* Jump to x + 16 MB moved to x + 20 MB */ p = buf; @@ -655,7 +654,7 @@ static void __init test_translate_branch(void) patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); - check(ppc_inst_equal(*q, ppc_inst(0x43ff8000))); + check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000))); /* Maximum positive case, move x to x - 32 KB + 4 */ p = buf + 0x8000; @@ -667,7 +666,7 @@ static void __init test_translate_branch(void) patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); - check(ppc_inst_equal(*q, ppc_inst(0x43ff7ffc))); + check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc))); /* Jump to x + 12 KB moved to x + 20 KB */ p = buf; diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c index 8c5d0db77013..f00dd13b1c3c 100644 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -48,7 +48,7 @@ static int patch_alt_instruction(struct ppc_inst *src, struct ppc_inst *dest, int err; struct ppc_inst instr; - instr = *src; + instr = ppc_inst_read(src); if (instr_is_relative_branch(*src)) { struct ppc_inst *target = (struct ppc_inst *)branch_target(src); diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index e3d8e1b8ce01..5e3949322a6c 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -705,13 +705,13 @@ static int xmon_core(struct pt_regs *regs, int fromipi) if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT)) { bp = at_breakpoint(regs->nip); if (bp != NULL) { - int stepped = emulate_step(regs, bp->instr[0]); + int stepped = emulate_step(regs, ppc_inst_read(bp->instr)); if (stepped == 0) { regs->nip = (unsigned long) &bp->instr[0]; atomic_inc(&bp->ref_count); } else if (stepped < 0) { printf("Couldn't single-step %s instruction\n", - (IS_RFID(bp->instr[0])? "rfid": "mtmsrd")); + IS_RFID(ppc_inst_read(bp->instr))? "rfid": "mtmsrd"); } } } @@ -952,7 +952,7 @@ static void remove_bpts(void) if (mread(bp->address, &instr, 4) == 4 && ppc_inst_equal(instr, ppc_inst(bpinstr)) && patch_instruction( - (struct ppc_inst *)bp->address, bp->instr[0]) != 0) + (struct ppc_inst *)bp->address, ppc_inst_read(bp->instr)) != 0) printf("Couldn't remove breakpoint at %lx\n", bp->address); } -- 2.17.1