Commit-ID: 78393fdde2a456cafa414b171c90f26a3df98b20 Gitweb: https://git.kernel.org/tip/78393fdde2a456cafa414b171c90f26a3df98b20 Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Tue, 13 Mar 2018 22:03:11 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 14 Mar 2018 09:21:01 +0100
selftests/x86/entry_from_vm86: Add test cases for POPF POPF is currently broken -- add tests to catch the error. This results in: [RUN] POPF with VIP set and IF clear from vm86 mode [INFO] Exited vm86 mode due to STI [FAIL] Incorrect return reason (started at eip = 0xd, ended at eip = 0xf) because POPF currently fails to check IF before reporting a pending interrupt. This patch also makes the FAIL message a bit more informative. Reported-by: Bart Oldeman <bartolde...@gmail.com> Signed-off-by: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stas Sergeev <s...@list.ru> Cc: Thomas Gleixner <t...@linutronix.de> Cc: sta...@vger.kernel.org Link: http://lkml.kernel.org/r/a16270b5cfe7832d6d00c479d0f871066cbdb52b.1521003603.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- tools/testing/selftests/x86/entry_from_vm86.c | 30 ++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/x86/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c index 6e85f0d0498d..ade443a88421 100644 --- a/tools/testing/selftests/x86/entry_from_vm86.c +++ b/tools/testing/selftests/x86/entry_from_vm86.c @@ -95,6 +95,10 @@ asm ( "int3\n\t" "vmcode_int80:\n\t" "int $0x80\n\t" + "vmcode_popf_hlt:\n\t" + "push %ax\n\t" + "popf\n\t" + "hlt\n\t" "vmcode_umip:\n\t" /* addressing via displacements */ "smsw (2052)\n\t" @@ -124,8 +128,8 @@ asm ( extern unsigned char vmcode[], end_vmcode[]; extern unsigned char vmcode_bound[], vmcode_sysenter[], vmcode_syscall[], - vmcode_sti[], vmcode_int3[], vmcode_int80[], vmcode_umip[], - vmcode_umip_str[], vmcode_umip_sldt[]; + vmcode_sti[], vmcode_int3[], vmcode_int80[], vmcode_popf_hlt[], + vmcode_umip[], vmcode_umip_str[], vmcode_umip_sldt[]; /* Returns false if the test was skipped. */ static bool do_test(struct vm86plus_struct *v86, unsigned long eip, @@ -175,7 +179,7 @@ static bool do_test(struct vm86plus_struct *v86, unsigned long eip, (VM86_TYPE(ret) == rettype && VM86_ARG(ret) == retarg)) { printf("[OK]\tReturned correctly\n"); } else { - printf("[FAIL]\tIncorrect return reason\n"); + printf("[FAIL]\tIncorrect return reason (started at eip = 0x%lx, ended at eip = 0x%lx)\n", eip, v86->regs.eip); nerrs++; } @@ -264,6 +268,9 @@ int main(void) v86.regs.ds = load_addr / 16; v86.regs.es = load_addr / 16; + /* Use the end of the page as our stack. */ + v86.regs.esp = 4096; + assert((v86.regs.cs & 3) == 0); /* Looks like RPL = 0 */ /* #BR -- should deliver SIG??? */ @@ -295,6 +302,23 @@ int main(void) v86.regs.eflags &= ~X86_EFLAGS_IF; do_test(&v86, vmcode_sti - vmcode, VM86_STI, 0, "STI with VIP set"); + /* POPF with VIP set but IF clear: should not trap */ + v86.regs.eflags = X86_EFLAGS_VIP; + v86.regs.eax = 0; + do_test(&v86, vmcode_popf_hlt - vmcode, VM86_UNKNOWN, 0, "POPF with VIP set and IF clear"); + + /* POPF with VIP set and IF set: should trap */ + v86.regs.eflags = X86_EFLAGS_VIP; + v86.regs.eax = X86_EFLAGS_IF; + do_test(&v86, vmcode_popf_hlt - vmcode, VM86_STI, 0, "POPF with VIP and IF set"); + + /* POPF with VIP clear and IF set: should not trap */ + v86.regs.eflags = 0; + v86.regs.eax = X86_EFLAGS_IF; + do_test(&v86, vmcode_popf_hlt - vmcode, VM86_UNKNOWN, 0, "POPF with VIP clear and IF set"); + + v86.regs.eflags = 0; + /* INT3 -- should cause #BP */ do_test(&v86, vmcode_int3 - vmcode, VM86_TRAP, 3, "INT3");
