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powerpc: Don't use 'struct ppc_inst' to reference instruction location

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'struct ppc_inst' is an internal representation of an instruction, but
in-memory instructions are and will remain a table of 'u32' forever.

Replace all 'struct ppc_inst *' used for locating an instruction in
memory by 'u32 *'. This removes a lot of undue casts to 'struct
ppc_inst *'.

It also helps locating ab-use of 'struct ppc_inst' dereference.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix ppc_inst_next(), use u32 instead of unsigned int]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy
2021-05-20 13:50:45 +00:00
committed by Michael Ellerman
parent e90a21ea80
commit 69d4d6e5fd
20 changed files with 159 additions and 176 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
arch/powerpc/kernel/optprobes.c
View File

@@ -89,9 +89,8 @@ 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(ppc_inst_read((struct ppc_inst *)p->ainsn.insn)) &&
analyse_instr(&op, &regs,
ppc_inst_read((struct ppc_inst *)p->ainsn.insn)) == 1) {
if (!is_conditional_branch(ppc_inst_read(p->ainsn.insn)) &&
analyse_instr(&op, &regs, ppc_inst_read(p->ainsn.insn)) == 1) {
emulate_update_regs(&regs, &op);
nip = regs.nip;
}
@@ -132,12 +131,10 @@ void arch_remove_optimized_kprobe(struct optimized_kprobe *op)
static void patch_imm32_load_insns(unsigned long val, int reg, kprobe_opcode_t *addr)
{
patch_instruction((struct ppc_inst *)addr,
ppc_inst(PPC_RAW_LIS(reg, IMM_H(val))));
patch_instruction(addr, ppc_inst(PPC_RAW_LIS(reg, IMM_H(val))));
addr++;
patch_instruction((struct ppc_inst *)addr,
ppc_inst(PPC_RAW_ORI(reg, reg, IMM_L(val))));
patch_instruction(addr, ppc_inst(PPC_RAW_ORI(reg, reg, IMM_L(val))));
}
/*
@@ -147,31 +144,31 @@ static void patch_imm32_load_insns(unsigned long val, int reg, kprobe_opcode_t *
static void patch_imm64_load_insns(unsigned long long val, int reg, kprobe_opcode_t *addr)
{
/* lis reg,(op)@highest */
patch_instruction((struct ppc_inst *)addr,
patch_instruction(addr,
ppc_inst(PPC_INST_ADDIS | ___PPC_RT(reg) |
((val >> 48) & 0xffff)));
addr++;
/* ori reg,reg,(op)@higher */
patch_instruction((struct ppc_inst *)addr,
patch_instruction(addr,
ppc_inst(PPC_INST_ORI | ___PPC_RA(reg) |
___PPC_RS(reg) | ((val >> 32) & 0xffff)));
addr++;
/* rldicr reg,reg,32,31 */
patch_instruction((struct ppc_inst *)addr,
patch_instruction(addr,
ppc_inst(PPC_INST_RLDICR | ___PPC_RA(reg) |
___PPC_RS(reg) | __PPC_SH64(32) | __PPC_ME64(31)));
addr++;
/* oris reg,reg,(op)@h */
patch_instruction((struct ppc_inst *)addr,
patch_instruction(addr,
ppc_inst(PPC_INST_ORIS | ___PPC_RA(reg) |
___PPC_RS(reg) | ((val >> 16) & 0xffff)));
addr++;
/* ori reg,reg,(op)@l */
patch_instruction((struct ppc_inst *)addr,
patch_instruction(addr,
ppc_inst(PPC_INST_ORI | ___PPC_RA(reg) |
___PPC_RS(reg) | (val & 0xffff)));
}
@@ -225,8 +222,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
size = (TMPL_END_IDX * sizeof(kprobe_opcode_t)) / sizeof(int);
pr_devel("Copying template to %p, size %lu\n", buff, size);
for (i = 0; i < size; i++) {
rc = patch_instruction((struct ppc_inst *)(buff + i),
ppc_inst(*(optprobe_template_entry + i)));
rc = patch_instruction(buff + i, ppc_inst(*(optprobe_template_entry + i)));
if (rc < 0)
goto error;
}
@@ -247,34 +243,30 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
goto error;
}
rc = create_branch(&branch_op_callback,
(struct ppc_inst *)(buff + TMPL_CALL_HDLR_IDX),
rc = create_branch(&branch_op_callback, buff + TMPL_CALL_HDLR_IDX,
(unsigned long)op_callback_addr,
BRANCH_SET_LINK);
rc |= create_branch(&branch_emulate_step,
(struct ppc_inst *)(buff + TMPL_EMULATE_IDX),
rc |= create_branch(&branch_emulate_step, buff + TMPL_EMULATE_IDX,
(unsigned long)emulate_step_addr,
BRANCH_SET_LINK);
if (rc)
goto error;
patch_instruction((struct ppc_inst *)(buff + TMPL_CALL_HDLR_IDX),
branch_op_callback);
patch_instruction((struct ppc_inst *)(buff + TMPL_EMULATE_IDX),
branch_emulate_step);
patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback);
patch_instruction(buff + TMPL_EMULATE_IDX, branch_emulate_step);
/*
* 3. load instruction to be emulated into relevant register, and
*/
temp = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
temp = ppc_inst_read(p->ainsn.insn);
patch_imm_load_insns(ppc_inst_as_ulong(temp), 4, buff + TMPL_INSN_IDX);
/*
* 4. branch back from trampoline
*/
patch_branch((struct ppc_inst *)(buff + TMPL_RET_IDX), (unsigned long)nip, 0);
patch_branch(buff + TMPL_RET_IDX, nip, 0);
flush_icache_range((unsigned long)buff,
(unsigned long)(&buff[TMPL_END_IDX]));
@@ -317,10 +309,9 @@ void arch_optimize_kprobes(struct list_head *oplist)
*/
memcpy(op->optinsn.copied_insn, op->kp.addr,
RELATIVEJUMP_SIZE);
create_branch(&instr,
(struct ppc_inst *)op->kp.addr,
create_branch(&instr, op->kp.addr,
(unsigned long)op->optinsn.insn, 0);
patch_instruction((struct ppc_inst *)op->kp.addr, instr);
patch_instruction(op->kp.addr, instr);
list_del_init(&op->list);
}
}