linux/arch/x86
Sean Christopherson 334872a091 x86/traps: Attempt to fixup exceptions in vDSO before signaling
vDSO functions can now leverage an exception fixup mechanism similar to
kernel exception fixup.  For vDSO exception fixup, the initial user is
Intel's Software Guard Extensions (SGX), which will wrap the low-level
transitions to/from the enclave, i.e. EENTER and ERESUME instructions,
in a vDSO function and leverage fixup to intercept exceptions that would
otherwise generate a signal.  This allows the vDSO wrapper to return the
fault information directly to its caller, obviating the need for SGX
applications and libraries to juggle signal handlers.

Attempt to fixup vDSO exceptions immediately prior to populating and
sending signal information.  Except for the delivery mechanism, an
exception in a vDSO function should be treated like any other exception
in userspace, e.g. any fault that is successfully handled by the kernel
should not be directly visible to userspace.

Although it's debatable whether or not all exceptions are of interest to
enclaves, defer to the vDSO fixup to decide whether to do fixup or
generate a signal.  Future users of vDSO fixup, if there ever are any,
will undoubtedly have different requirements than SGX enclaves, e.g. the
fixup vs. signal logic can be made function specific if/when necessary.

Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-19-jarkko@kernel.org
2020-11-18 18:02:50 +01:00
..
boot x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path 2020-10-29 18:06:52 +01:00
configs * A defconfig fix, from Daniel Díaz. 2020-09-20 15:06:43 -07:00
crypto crypto: x86/poly1305 - add back a needed assignment 2020-10-24 09:38:32 +11:00
entry x86/vdso: Add support for exception fixup in vDSO functions 2020-11-18 18:02:50 +01:00
events perf/x86/intel/uncore: Fix Add BW copypasta 2020-11-10 18:38:40 +01:00
hyperv hyperv-fixes for 5.10-rc3 2020-11-05 11:32:03 -08:00
ia32 x86: remove address space overrides using set_fs() 2020-09-08 22:21:36 -04:00
include x86/vdso: Add support for exception fixup in vDSO functions 2020-11-18 18:02:50 +01:00
kernel x86/traps: Attempt to fixup exceptions in vDSO before signaling 2020-11-18 18:02:50 +01:00
kvm Fixes for ARM and x86, the latter especially for old processors 2020-11-15 09:57:58 -08:00
lib x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S 2020-11-04 12:30:20 +01:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mm x86/traps: Attempt to fixup exceptions in vDSO before signaling 2020-11-18 18:02:50 +01:00
net bpf: x64: Do not emit sub/add 0, %rsp when !stack_depth 2020-09-29 16:47:39 -07:00
oprofile
pci pci-v5.10-changes 2020-10-22 12:41:00 -07:00
platform treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
ras treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
realmode x86/head/64: Don't call verify_cpu() on starting APs 2020-09-09 11:33:20 +02:00
tools x86/insn: Make inat-tables.c suitable for pre-decompression code 2020-09-07 19:45:24 +02:00
um arch/um: partially revert the conversion to __section() macro 2020-10-26 15:39:37 -07:00
video
xen treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
.gitignore
Kbuild
Kconfig x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections 2020-11-17 14:36:13 +01:00
Kconfig.assembler x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
Kconfig.cpu treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Kconfig.debug x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
Makefile x86/build: Warn on orphan section placement 2020-09-03 10:28:36 +02:00
Makefile_32.cpu
Makefile.um