Commit-ID: a4455082dc6f0b5d51a23523f77600e8ede47c79
Gitweb: http://git.kernel.org/tip/a4455082dc6f0b5d51a23523f77600e8ede47c79
Author: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 8 Jun 2016 10:25:33 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 14 Jun 2016 12:19:24 +0200
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: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: linux-edac@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160608172533.F8F05637@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/compat.h | 11 +++++++++++
arch/x86/kernel/signal_compat.c | 15 +++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 5a3b2c1..a188061 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -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 {
/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
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;
/* SIGPOLL */
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index dc3c0b1..5335ad9 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -32,6 +32,21 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
&to->_sifields._pad[0]);
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);
+ }
break;
case __SI_SYS >> 16:
put_user_ex(from->si_syscall, &to->si_syscall);
--
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