From 544f1d62e3e6c6e6d17a5e56f6139208acb5ff46 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Thu, 31 Oct 2019 18:25:16 +0100 Subject: [PATCH] s390/disassembler: don't hide instruction addresses Due to kptr_restrict, JITted BPF code is now displayed like this: 000000000b6ed1b2: ebdff0800024 stmg %r13,%r15,128(%r15) 000000004cde2ba0: 41d0f040 la %r13,64(%r15) 00000000fbad41b0: a7fbffa0 aghi %r15,-96 Leaking kernel addresses to dmesg is not a concern in this case, because this happens only when JIT debugging is explicitly activated, which only root can do. Use %px in this particular instance, and also to print an instruction address in show_code and PCREL (e.g. brasl) arguments in print_insn. While at present functionally equivalent to %016lx, %px is recommended by Documentation/core-api/printk-formats.rst for such cases. Signed-off-by: Ilya Leoshkevich Reviewed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dis.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c index 7abe6ae261b4..f304802ecf7b 100644 --- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -461,10 +461,11 @@ static int print_insn(char *buffer, unsigned char *code, unsigned long addr) ptr += sprintf(ptr, "%%c%i", value); else if (operand->flags & OPERAND_VR) ptr += sprintf(ptr, "%%v%i", value); - else if (operand->flags & OPERAND_PCREL) - ptr += sprintf(ptr, "%lx", (signed int) value - + addr); - else if (operand->flags & OPERAND_SIGNED) + else if (operand->flags & OPERAND_PCREL) { + void *pcrel = (void *)((int)value + addr); + + ptr += sprintf(ptr, "%px", pcrel); + } else if (operand->flags & OPERAND_SIGNED) ptr += sprintf(ptr, "%i", value); else ptr += sprintf(ptr, "%u", value); @@ -536,7 +537,7 @@ void show_code(struct pt_regs *regs) else *ptr++ = ' '; addr = regs->psw.addr + start - 32; - ptr += sprintf(ptr, "%016lx: ", addr); + ptr += sprintf(ptr, "%px: ", (void *)addr); if (start + opsize >= end) break; for (i = 0; i < opsize; i++) @@ -564,7 +565,7 @@ void print_fn_code(unsigned char *code, unsigned long len) opsize = insn_length(*code); if (opsize > len) break; - ptr += sprintf(ptr, "%p: ", code); + ptr += sprintf(ptr, "%px: ", code); for (i = 0; i < opsize; i++) ptr += sprintf(ptr, "%02x", code[i]); *ptr++ = '\t';