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s390/disassembler: don't hide instruction addresses
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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 <iii@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Ilya Leoshkevich authored and Vasily Gorbik committed Nov 12, 2019
1 parent 72fbcd0 commit 544f1d6
Showing 1 changed file with 7 additions and 6 deletions.
13 changes: 7 additions & 6 deletions arch/s390/kernel/dis.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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++)
Expand Down Expand Up @@ -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';
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