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| author | kib <kib@FreeBSD.org> | 2017-09-11 08:48:36 +0000 |
|---|---|---|
| committer | Luiz Souza <luiz@netgate.com> | 2018-02-19 14:31:40 -0300 |
| commit | 2589da26b930eaf9441b6bf27c0f410062adf507 (patch) | |
| tree | f814d1d2fffd5b06bf6cc8ee0a35de86abc861ab /sys/amd64/amd64/exception.S | |
| parent | e4ceef150ec3bdd258987bf82d56662293bb1ace (diff) | |
| download | FreeBSD-src-2589da26b930eaf9441b6bf27c0f410062adf507.zip FreeBSD-src-2589da26b930eaf9441b6bf27c0f410062adf507.tar.gz | |
MFC r322762, r322799, r322832, r322833:
Make WRFSBASE and WRGSBASE instructions functional.
(cherry picked from commit b1a7a7418e73251aad628dc4f9418e550a9fd3d7)
Diffstat (limited to 'sys/amd64/amd64/exception.S')
| -rw-r--r-- | sys/amd64/amd64/exception.S | 67 |
1 files changed, 54 insertions, 13 deletions
diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S index 2c2b99b..c288f3d 100644 --- a/sys/amd64/amd64/exception.S +++ b/sys/amd64/amd64/exception.S @@ -187,12 +187,13 @@ alltraps_testi: jz alltraps_pushregs_no_rdi sti alltraps_pushregs_no_rdi: - movq %rsi,TF_RSI(%rsp) movq %rdx,TF_RDX(%rsp) + movq %rax,TF_RAX(%rsp) +alltraps_pushregs_no_rax: + movq %rsi,TF_RSI(%rsp) movq %rcx,TF_RCX(%rsp) movq %r8,TF_R8(%rsp) movq %r9,TF_R9(%rsp) - movq %rax,TF_RAX(%rsp) movq %rbx,TF_RBX(%rsp) movq %rbp,TF_RBP(%rsp) movq %r10,TF_R10(%rsp) @@ -326,22 +327,44 @@ IDTVEC(prot) prot_addrf: movq $0,TF_ADDR(%rsp) movq %rdi,TF_RDI(%rsp) /* free up a GP register */ + movq %rax,TF_RAX(%rsp) + movq %rdx,TF_RDX(%rsp) + movw %fs,TF_FS(%rsp) + movw %gs,TF_GS(%rsp) leaq doreti_iret(%rip),%rdi cmpq %rdi,TF_RIP(%rsp) - je 1f /* kernel but with user gsbase!! */ + je 5f /* kernel but with user gsbase!! */ testb $SEL_RPL_MASK,TF_CS(%rsp) /* Did we come from kernel? */ - jz 2f /* already running with kernel GS.base */ -1: swapgs -2: movq PCPU(CURPCB),%rdi - orl $PCB_FULL_IRET,PCB_FLAGS(%rdi) /* always full iret from GPF */ - movw %fs,TF_FS(%rsp) - movw %gs,TF_GS(%rsp) + jz 6f /* already running with kernel GS.base */ + testb $CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip) + jz 2f + cmpw $KUF32SEL,TF_FS(%rsp) + jne 1f + rdfsbaseq %rax +1: cmpw $KUG32SEL,TF_GS(%rsp) + jne 2f + rdgsbaseq %rdx +2: swapgs + movq PCPU(CURPCB),%rdi + testb $CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip) + jz 4f + cmpw $KUF32SEL,TF_FS(%rsp) + jne 3f + movq %rax,PCB_FSBASE(%rdi) +3: cmpw $KUG32SEL,TF_GS(%rsp) + jne 4f + movq %rdx,PCB_GSBASE(%rdi) +4: orl $PCB_FULL_IRET,PCB_FLAGS(%rdi) /* always full iret from GPF */ movw %es,TF_ES(%rsp) movw %ds,TF_DS(%rsp) testl $PSL_I,TF_RFLAGS(%rsp) - jz alltraps_pushregs_no_rdi + jz alltraps_pushregs_no_rax sti - jmp alltraps_pushregs_no_rdi + jmp alltraps_pushregs_no_rax + +5: swapgs +6: movq PCPU(CURPCB),%rdi + jmp 4b /* * Fast syscall entry point. We enter here with just our new %cs/%ss set, @@ -349,8 +372,8 @@ prot_addrf: * pointer. We have to juggle a few things around to find our stack etc. * swapgs gives us access to our PCPU space only. * - * We do not support invoking this from a custom %cs or %ss (e.g. using - * entries from an LDT). + * We do not support invoking this from a custom segment registers, + * esp. %cs, %ss, %fs, %gs, e.g. using entries from an LDT. */ IDTVEC(fast_syscall) swapgs @@ -503,6 +526,23 @@ IDTVEC(nmi) nmi_fromuserspace: incl %ebx swapgs + testb $CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip) + jz 2f + movq PCPU(CURPCB),%rdi + testq %rdi,%rdi + jz 2f + cmpw $KUF32SEL,TF_FS(%rsp) + jne 1f + rdfsbaseq %rax + movq %rax,PCB_FSBASE(%rdi) +1: cmpw $KUG32SEL,TF_GS(%rsp) + jne 2f + movl $MSR_KGSBASE,%ecx + rdmsr + shlq $32,%rdx + orq %rdx,%rax + movq %rax,PCB_GSBASE(%rdi) +2: /* Note: this label is also used by ddb and gdb: */ nmi_calltrap: FAKE_MCOUNT(TF_RIP(%rsp)) @@ -705,6 +745,7 @@ doreti_exit: jz ld_regs testl $PCB_FULL_IRET,PCB_FLAGS(%r8) jz ld_regs + andl $~PCB_FULL_IRET,PCB_FLAGS(%r8) testl $TF_HASSEGS,TF_FLAGS(%rsp) je set_segs |
