Commit a4455082 authored by Dave Hansen's avatar Dave Hansen Committed by Ingo Molnar
Browse files

x86/signals: Add missing signal_compat code for x86 features

The 32-bit siginfo is a different binary format than the 64-bit
one.  So, when running 32-bit binaries on 64-bit kernels, we have
to convert the kernel's 64-bit version to a 32-bit version that
userspace can grok.

We've added a few features to siginfo over the past few years and
neglected to add them to arch/x86/kernel/signal_compat.c:

   1. The si_addr_lsb used in SIGBUS's sent for machine checks
   2. The upper/lower bounds for MPX SIGSEGV faults
   3. The protection key for pkey faults

I caught this with some protection keys unit tests and realized
it affected a few more features.

This was tested only with my protection keys patch that looks
for a proper value in si_pkey.  I didn't actually test the machine
check or MPX code.
Signed-off-by: default avatarDave Hansen <>
Cc: Al Viro <>
Cc: Andy Lutomirski <>
Cc: Borislav Petkov <>
Cc: Brian Gerst <>
Cc: Dave Hansen <>
Cc: Denys Vlasenko <>
Cc: H. Peter Anvin <>
Cc: Linus Torvalds <>
Cc: Oleg Nesterov <>
Cc: Peter Zijlstra <>
Cc: Thomas Gleixner <>
Cc: Tony Luck <>

Signed-off-by: default avatarIngo Molnar <>
parent f0702555
......@@ -40,6 +40,7 @@ typedef s32 compat_long_t;
typedef s64 __attribute__((aligned(4))) compat_s64;
typedef u32 compat_uint_t;
typedef u32 compat_ulong_t;
typedef u32 compat_u32;
typedef u64 __attribute__((aligned(4))) compat_u64;
typedef u32 compat_uptr_t;
......@@ -181,6 +182,16 @@ typedef struct compat_siginfo {
struct {
unsigned int _addr; /* faulting insn/memory ref. */
short int _addr_lsb; /* Valid LSB of the reported address. */
union {
/* used when si_code=SEGV_BNDERR */
struct {
compat_uptr_t _lower;
compat_uptr_t _upper;
} _addr_bnd;
/* used when si_code=SEGV_PKUERR */
compat_u32 _pkey;
} _sigfault;
......@@ -32,6 +32,21 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
if (from->si_signo == SIGBUS &&
(from->si_code == BUS_MCEERR_AR ||
from->si_code == BUS_MCEERR_AO))
put_user_ex(from->si_addr_lsb, &to->si_addr_lsb);
if (from->si_signo == SIGSEGV) {
if (from->si_code == SEGV_BNDERR) {
compat_uptr_t lower = (unsigned long)&to->si_lower;
compat_uptr_t upper = (unsigned long)&to->si_upper;
put_user_ex(lower, &to->si_lower);
put_user_ex(upper, &to->si_upper);
if (from->si_code == SEGV_PKUERR)
put_user_ex(from->si_pkey, &to->si_pkey);
case __SI_SYS >> 16:
put_user_ex(from->si_syscall, &to->si_syscall);
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment