diff options
author | Dave Hansen <dave.hansen@linux.intel.com> | 2020-01-23 21:41:15 +0300 |
---|---|---|
committer | Dave Hansen <dave.hansen@intel.com> | 2020-01-23 21:41:15 +0300 |
commit | aa9ccb7b47f909e2e7206ebb47e4c63e477199fc (patch) | |
tree | 76592fb190eada40e527c4791a76839d838c7f9a /arch | |
parent | 4ba68d00055774308ede6c4c2133e5a8b70a2ab8 (diff) | |
download | linux-aa9ccb7b47f909e2e7206ebb47e4c63e477199fc.tar.xz |
x86/mpx: remove bounds exception code
From: Dave Hansen <dave.hansen@linux.intel.com>
MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).
Remove the other user-visible ABI: signal handling. This code
should basically have been inactive after the prctl()s were
removed, but there may be some small ABI remnants from this code.
Remove it.
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/traps.c | 74 |
1 files changed, 0 insertions, 74 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 4bb0f8447112..6fd5b7561444 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -57,8 +57,6 @@ #include <asm/mach_traps.h> #include <asm/alternative.h> #include <asm/fpu/xstate.h> -#include <asm/trace/mpx.h> -#include <asm/mpx.h> #include <asm/vm86.h> #include <asm/umip.h> @@ -430,8 +428,6 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) { - const struct mpx_bndcsr *bndcsr; - RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); if (notify_die(DIE_TRAP, "bounds", regs, error_code, X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP) @@ -441,76 +437,6 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) if (!user_mode(regs)) die("bounds", regs, error_code); - if (!cpu_feature_enabled(X86_FEATURE_MPX)) { - /* The exception is not from Intel MPX */ - goto exit_trap; - } - - /* - * We need to look at BNDSTATUS to resolve this exception. - * A NULL here might mean that it is in its 'init state', - * which is all zeros which indicates MPX was not - * responsible for the exception. - */ - bndcsr = get_xsave_field_ptr(XFEATURE_BNDCSR); - if (!bndcsr) - goto exit_trap; - - trace_bounds_exception_mpx(bndcsr); - /* - * The error code field of the BNDSTATUS register communicates status - * information of a bound range exception #BR or operation involving - * bound directory. - */ - switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) { - case 2: /* Bound directory has invalid entry. */ - if (mpx_handle_bd_fault()) - goto exit_trap; - break; /* Success, it was handled */ - case 1: /* Bound violation. */ - { - struct task_struct *tsk = current; - struct mpx_fault_info mpx; - - if (mpx_fault_info(&mpx, regs)) { - /* - * We failed to decode the MPX instruction. Act as if - * the exception was not caused by MPX. - */ - goto exit_trap; - } - /* - * Success, we decoded the instruction and retrieved - * an 'mpx' containing the address being accessed - * which caused the exception. This information - * allows and application to possibly handle the - * #BR exception itself. - */ - if (!do_trap_no_signal(tsk, X86_TRAP_BR, "bounds", regs, - error_code)) - break; - - show_signal(tsk, SIGSEGV, "trap ", "bounds", regs, error_code); - - force_sig_bnderr(mpx.addr, mpx.lower, mpx.upper); - break; - } - case 0: /* No exception caused by Intel MPX operations. */ - goto exit_trap; - default: - die("bounds", regs, error_code); - } - - return; - -exit_trap: - /* - * This path out is for all the cases where we could not - * handle the exception in some way (like allocating a - * table or telling userspace about it. We will also end - * up here if the kernel has MPX turned off at compile - * time.. - */ do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, 0, NULL); } |