Messages in this thread Patch in this message | | | Subject | [PATCH 1/3] x86, signals: add missing signal_compat code for x86 features | From | Dave Hansen <> | Date | Wed, 08 Jun 2016 10:25:33 -0700 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
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@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: linux-edac@vger.kernel.org Cc: x86@kernel.org Cc: Andy Lutomirski <luto@kernel.org> ---
b/arch/x86/include/asm/compat.h | 11 +++++++++++ b/arch/x86/kernel/signal_compat.c | 15 +++++++++++++++ 2 files changed, 26 insertions(+)
diff -puN arch/x86/include/asm/compat.h~add-signal-compat-for-mpx-pkeys arch/x86/include/asm/compat.h --- a/arch/x86/include/asm/compat.h~add-signal-compat-for-mpx-pkeys 2016-06-08 10:23:23.559472773 -0700 +++ b/arch/x86/include/asm/compat.h 2016-06-08 10:23:23.564472998 -0700 @@ -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 -puN arch/x86/kernel/signal_compat.c~add-signal-compat-for-mpx-pkeys arch/x86/kernel/signal_compat.c --- a/arch/x86/kernel/signal_compat.c~add-signal-compat-for-mpx-pkeys 2016-06-08 10:23:23.561472863 -0700 +++ b/arch/x86/kernel/signal_compat.c 2016-06-08 10:23:23.565473043 -0700 @@ -32,6 +32,21 @@ int copy_siginfo_to_user32(compat_siginf &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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