diff options
Diffstat (limited to 'arch/mips/kernel')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 25 | ||||
| -rw-r--r-- | arch/mips/kernel/genex.S | 8 |
2 files changed, 25 insertions, 8 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index f39e85fd58fa..b15615b28569 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -54,10 +54,20 @@ static inline void ftrace_dyn_arch_init_insns(void) u32 *buf; unsigned int v1; - /* la v1, _mcount */ - v1 = 3; - buf = (u32 *)&insn_la_mcount[0]; - UASM_i_LA(&buf, v1, MCOUNT_ADDR); + /* If we are not in compat space, the number of generated + * instructions will exceed the maximum expected limit of 2. + * To prevent buffer overflow, we avoid generating them. + * insn_la_mcount will not be used later in ftrace_make_call. + */ + if (uasm_in_compat_space_p(MCOUNT_ADDR)) { + /* la v1, _mcount */ + v1 = 3; + buf = (u32 *)&insn_la_mcount[0]; + UASM_i_LA(&buf, v1, MCOUNT_ADDR); + } else { + pr_warn("ftrace: mcount address beyond 32 bits is not supported (%lX)\n", + MCOUNT_ADDR); + } /* jal (ftrace_caller + 8), jump over the first two instruction */ buf = (u32 *)&insn_jal_ftrace_caller; @@ -189,6 +199,13 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) unsigned int new; unsigned long ip = rec->ip; + /* When the code to patch does not belong to the kernel code + * space, we must use insn_la_mcount. However, if MCOUNT_ADDR + * is not in compat space, insn_la_mcount is not usable. + */ + if (!core_kernel_text(ip) && !uasm_in_compat_space_p(MCOUNT_ADDR)) + return -EFAULT; + new = core_kernel_text(ip) ? insn_jal_ftrace_caller : insn_la_mcount[0]; #ifdef CONFIG_64BIT diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S index 08c0a01d9a29..be1b049d856f 100644 --- a/arch/mips/kernel/genex.S +++ b/arch/mips/kernel/genex.S @@ -109,7 +109,7 @@ handle_vcei: .align 5 LEAF(r4k_wait) /* Keep the ISA bit clear for calculations on local labels here. */ -0: .fill 0 +0: .fill 0 /* Start of idle interrupt region. */ local_irq_enable /* @@ -121,7 +121,7 @@ LEAF(r4k_wait) */ 1: .fill 0 /* The R2 EI/EHB sequence takes 8 bytes, otherwise pad up. */ - .if 1b - 0b > 32 + .if 1b - 0b > 32 .error "overlong idle interrupt region" .elseif 1b - 0b > 8 .align 4 @@ -146,10 +146,10 @@ r4k_wait_exit: MFC0 k0, CP0_EPC /* Subtract/add 2 to let the ISA bit propagate through the mask. */ PTR_LA k1, r4k_wait_insn - 2 - ori k0, r4k_wait_idle_size - 2 + ori k0, r4k_wait_idle_size - 2 .set noreorder bne k0, k1, \handler - PTR_ADDIU k0, r4k_wait_exit - r4k_wait_insn + 2 + PTR_ADDIU k0, r4k_wait_exit - r4k_wait_insn + 2 .set reorder MTC0 k0, CP0_EPC .set pop |