[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging-4.10] x86/pv: Move exception injection into {, compat_}test_all_events()
commit 9abae6f7a867d3437141f95cbb030c1841ca97e6 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Tue May 8 18:14:35 2018 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue May 8 18:14:35 2018 +0100 x86/pv: Move exception injection into {,compat_}test_all_events() This allows paths to jump straight to {,compat_}test_all_events() and have injection of pending exceptions happen automatically, rather than requiring all calling paths to handle exceptions themselves. The normal exception path is simplified as a result, and compat_post_handle_exception() is removed entirely. This is part of XSA-260 / CVE-2018-8897. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> --- xen/arch/x86/x86_64/compat/entry.S | 24 +++++++++++++++--------- xen/arch/x86/x86_64/entry.S | 23 ++++++++++++++++------- 2 files changed, 31 insertions(+), 16 deletions(-) diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S index 75497bc292..4dc539e271 100644 --- a/xen/arch/x86/x86_64/compat/entry.S +++ b/xen/arch/x86/x86_64/compat/entry.S @@ -39,6 +39,12 @@ ENTRY(compat_test_all_events) leaq irq_stat+IRQSTAT_softirq_pending(%rip),%rcx cmpl $0,(%rcx,%rax,1) jne compat_process_softirqs + + /* Inject exception if pending. */ + lea VCPU_trap_bounce(%rbx), %rdx + testb $TBF_EXCEPTION, TRAPBOUNCE_flags(%rdx) + jnz .Lcompat_process_trapbounce + testb $1,VCPU_mce_pending(%rbx) jnz compat_process_mce .Lcompat_test_guest_nmi: @@ -68,6 +74,15 @@ compat_process_softirqs: call do_softirq jmp compat_test_all_events + ALIGN +/* %rbx: struct vcpu, %rdx: struct trap_bounce */ +.Lcompat_process_trapbounce: + sti +.Lcompat_bounce_exception: + call compat_create_bounce_frame + movb $0, TRAPBOUNCE_flags(%rdx) + jmp compat_test_all_events + ALIGN /* %rbx: struct vcpu */ compat_process_mce: @@ -189,15 +204,6 @@ ENTRY(cr4_pv32_restore) xor %eax, %eax ret -/* %rdx: trap_bounce, %rbx: struct vcpu */ -ENTRY(compat_post_handle_exception) - testb $TBF_EXCEPTION,TRAPBOUNCE_flags(%rdx) - jz compat_test_all_events -.Lcompat_bounce_exception: - call compat_create_bounce_frame - movb $0,TRAPBOUNCE_flags(%rdx) - jmp compat_test_all_events - .section .text.entry, "ax", @progbits /* See lstar_enter for entry register state. */ diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index bdd33e727f..3e9b4128bd 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -42,6 +42,12 @@ test_all_events: leaq irq_stat+IRQSTAT_softirq_pending(%rip), %rcx cmpl $0, (%rcx, %rax, 1) jne process_softirqs + + /* Inject exception if pending. */ + lea VCPU_trap_bounce(%rbx), %rdx + testb $TBF_EXCEPTION, TRAPBOUNCE_flags(%rdx) + jnz .Lprocess_trapbounce + cmpb $0, VCPU_mce_pending(%rbx) jne process_mce .Ltest_guest_nmi: @@ -70,6 +76,15 @@ process_softirqs: jmp test_all_events ALIGN +/* %rbx: struct vcpu, %rdx struct trap_bounce */ +.Lprocess_trapbounce: + sti +.Lbounce_exception: + call create_bounce_frame + movb $0, TRAPBOUNCE_flags(%rdx) + jmp test_all_events + + ALIGN /* %rbx: struct vcpu */ process_mce: testb $1 << VCPU_TRAP_MCE, VCPU_async_exception_mask(%rbx) @@ -667,15 +682,9 @@ handle_exception_saved: mov %r15, STACK_CPUINFO_FIELD(xen_cr3)(%r14) testb $3,UREGS_cs(%rsp) jz restore_all_xen - leaq VCPU_trap_bounce(%rbx),%rdx movq VCPU_domain(%rbx),%rax testb $1,DOMAIN_is_32bit_pv(%rax) - jnz compat_post_handle_exception - testb $TBF_EXCEPTION,TRAPBOUNCE_flags(%rdx) - jz test_all_events -.Lbounce_exception: - call create_bounce_frame - movb $0,TRAPBOUNCE_flags(%rdx) + jnz compat_test_all_events jmp test_all_events /* No special register assumptions. */ -- generated by git-patchbot for /home/xen/git/xen.git#staging-4.10 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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