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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-29 19:36:22 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-29 19:36:22 +0300
commit65f4d6d0f80b3c55830ec5735194703fa2909ba1 (patch)
tree1a7ea2b9ccad8a38364e888bb927564329059e0e /tools
parent810fb07a9b504ac22b95899cf8b39d25a5f3e5c5 (diff)
parent8bb2610bc4967f19672444a7b0407367f1540028 (diff)
downloadlinux-65f4d6d0f80b3c55830ec5735194703fa2909ba1.tar.xz
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti fixes from Thomas Gleixner: "A set of updates for the x86/pti related code: - Preserve r8-r11 in int $0x80. r8-r11 need to be preserved, but the int$80 entry code removed that quite some time ago. Make it correct again. - A set of fixes for the Global Bit work which went into 4.17 and caused a bunch of interesting regressions: - Triggering a BUG in the page attribute code due to a missing check for early boot stage - Warnings in the page attribute code about holes in the kernel text mapping which are caused by the freeing of the init code. Handle such holes gracefully. - Reduce the amount of kernel memory which is set global to the actual text and do not incidentally overlap with data. - Disable the global bit when RANDSTRUCT is enabled as it partially defeats the hardening. - Make the page protection setup correct for vma->page_prot population again. The adjustment of the protections fell through the crack during the Global bit rework and triggers warnings on machines which do not support certain features, e.g. NX" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry/64/compat: Preserve r8-r11 in int $0x80 x86/pti: Filter at vma->vm_page_prot population x86/pti: Disallow global kernel text with RANDSTRUCT x86/pti: Reduce amount of kernel text allowed to be Global x86/pti: Fix boot warning from Global-bit setting x86/pti: Fix boot problems from Global-bit setting
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/x86/test_syscall_vdso.c35
1 files changed, 21 insertions, 14 deletions
diff --git a/tools/testing/selftests/x86/test_syscall_vdso.c b/tools/testing/selftests/x86/test_syscall_vdso.c
index 40370354d4c1..c9c3281077bc 100644
--- a/tools/testing/selftests/x86/test_syscall_vdso.c
+++ b/tools/testing/selftests/x86/test_syscall_vdso.c
@@ -100,12 +100,19 @@ asm (
" shl $32, %r8\n"
" orq $0x7f7f7f7f, %r8\n"
" movq %r8, %r9\n"
- " movq %r8, %r10\n"
- " movq %r8, %r11\n"
- " movq %r8, %r12\n"
- " movq %r8, %r13\n"
- " movq %r8, %r14\n"
- " movq %r8, %r15\n"
+ " incq %r9\n"
+ " movq %r9, %r10\n"
+ " incq %r10\n"
+ " movq %r10, %r11\n"
+ " incq %r11\n"
+ " movq %r11, %r12\n"
+ " incq %r12\n"
+ " movq %r12, %r13\n"
+ " incq %r13\n"
+ " movq %r13, %r14\n"
+ " incq %r14\n"
+ " movq %r14, %r15\n"
+ " incq %r15\n"
" ret\n"
" .code32\n"
" .popsection\n"
@@ -128,12 +135,13 @@ int check_regs64(void)
int err = 0;
int num = 8;
uint64_t *r64 = &regs64.r8;
+ uint64_t expected = 0x7f7f7f7f7f7f7f7fULL;
if (!kernel_is_64bit)
return 0;
do {
- if (*r64 == 0x7f7f7f7f7f7f7f7fULL)
+ if (*r64 == expected++)
continue; /* register did not change */
if (syscall_addr != (long)&int80) {
/*
@@ -147,18 +155,17 @@ int check_regs64(void)
continue;
}
} else {
- /* INT80 syscall entrypoint can be used by
+ /*
+ * INT80 syscall entrypoint can be used by
* 64-bit programs too, unlike SYSCALL/SYSENTER.
* Therefore it must preserve R12+
* (they are callee-saved registers in 64-bit C ABI).
*
- * This was probably historically not intended,
- * but R8..11 are clobbered (cleared to 0).
- * IOW: they are the only registers which aren't
- * preserved across INT80 syscall.
+ * Starting in Linux 4.17 (and any kernel that
+ * backports the change), R8..11 are preserved.
+ * Historically (and probably unintentionally), they
+ * were clobbered or zeroed.
*/
- if (*r64 == 0 && num <= 11)
- continue;
}
printf("[FAIL]\tR%d has changed:%016llx\n", num, *r64);
err++;