diff options
author | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
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committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/tools/testing/selftests/x86/thunks_32.S | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/tools/testing/selftests/x86/thunks_32.S')
-rw-r--r-- | kernel/tools/testing/selftests/x86/thunks_32.S | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/x86/thunks_32.S b/kernel/tools/testing/selftests/x86/thunks_32.S new file mode 100644 index 000000000..29b644bb9 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/thunks_32.S @@ -0,0 +1,55 @@ +/* + * thunks_32.S - assembly helpers for mixed-bitness code + * Copyright (c) 2015 Denys Vlasenko + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * These are little helpers that make it easier to switch bitness on + * the fly. + */ + + .text + .code32 + + .global call64_from_32 + .type call32_from_64, @function + + // 4(%esp): function to call +call64_from_32: + // Fetch function address + mov 4(%esp), %eax + + // Save registers which are callee-clobbered by 64-bit ABI + push %ecx + push %edx + push %esi + push %edi + + // Switch to long mode + jmp $0x33,$1f +1: .code64 + + // Call the function + call *%rax + + // Switch to compatibility mode + push $0x23 /* USER32_CS */ + .code32; push $1f; .code64 /* hack: can't have X86_64_32S relocation in 32-bit ELF */ + lretq +1: .code32 + + pop %edi + pop %esi + pop %edx + pop %ecx + + ret + +.size call64_from_32, .-call64_from_32 |