Commit-ID: a4455082dc6f0b5d51a23523f77600e8ede47c79 Gitweb: http://git.kernel.org/tip/a4455082dc6f0b5d51a23523f77600e8ede47c79 Author: Dave Hansen <[email protected]> AuthorDate: Wed, 8 Jun 2016 10:25:33 -0700 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Cc: Al Viro <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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);
