[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] x86/asm: Drop __GET_CURRENT()
__GET_CURRENT() is very dangerous to use, as is easy to confuse with GET_CURRENT(), but strictly depends on the regster parameter already having the STACK_END value in it. Also, there is no reason to special case accesses of current_vcpu differently to other cpuinfo fields. Expand __GET_CURRENT() in its current users, and remove the macro. Take the opportunity to replace the GET_CURRENT() in the cstar path which doesn't need to recalculate STACK_END. No functional change. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- CC: Jan Beulich <JBeulich@xxxxxxxx> --- xen/arch/x86/x86_64/compat/entry.S | 2 +- xen/arch/x86/x86_64/entry.S | 8 ++++---- xen/include/asm-x86/asm_defns.h | 4 +--- 3 files changed, 6 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S index 4190c73..8fc594f 100644 --- a/xen/arch/x86/x86_64/compat/entry.S +++ b/xen/arch/x86/x86_64/compat/entry.S @@ -224,7 +224,7 @@ ENTRY(cstar_enter) movq $0, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) .Lcstar_cr3_okay: - GET_CURRENT(bx) + movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx movq VCPU_domain(%rbx),%rcx cmpb $0,DOMAIN_is_32bit_pv(%rcx) je switch_to_kernel diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index a5a6702..308bbf3 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -171,7 +171,7 @@ ENTRY(lstar_enter) movq $0, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) .Llstar_cr3_okay: - __GET_CURRENT(bx) + movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx testb $TF_kernel_mode,VCPU_thread_flags(%rbx) jz switch_to_kernel @@ -277,7 +277,7 @@ GLOBAL(sysenter_eflags_saved) movq $0, STACK_CPUINFO_FIELD(xen_cr3)(%rbx) .Lsyse_cr3_okay: - __GET_CURRENT(bx) + movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx cmpb $0,VCPU_sysenter_disables_events(%rbx) movq VCPU_sysenter_addr(%rbx),%rax setne %cl @@ -332,7 +332,7 @@ UNLIKELY_START(ne, msi_check) call check_for_unexpected_msi UNLIKELY_END(msi_check) - __GET_CURRENT(bx) + movq STACK_CPUINFO_FIELD(current_vcpu)(%rbx), %rbx /* Check that the callback is non-null. */ leaq VCPU_int80_bounce(%rbx),%rdx @@ -477,7 +477,7 @@ ENTRY(dom_crash_sync_extable) GET_STACK_END(ax) leaq STACK_CPUINFO_FIELD(guest_cpu_user_regs)(%rax),%rsp # create_bounce_frame() temporarily clobbers CS.RPL. Fix up. - __GET_CURRENT(ax) + movq STACK_CPUINFO_FIELD(current_vcpu)(%rax), %rax movq VCPU_domain(%rax),%rax testb $1,DOMAIN_is_32bit_pv(%rax) setz %al diff --git a/xen/include/asm-x86/asm_defns.h b/xen/include/asm-x86/asm_defns.h index 88b775b..aee14ba 100644 --- a/xen/include/asm-x86/asm_defns.h +++ b/xen/include/asm-x86/asm_defns.h @@ -132,11 +132,9 @@ void ret_from_intr(void); GET_STACK_END(reg); \ addq $STACK_CPUINFO_FIELD(field), %r##reg -#define __GET_CURRENT(reg) \ - movq STACK_CPUINFO_FIELD(current_vcpu)(%r##reg), %r##reg #define GET_CURRENT(reg) \ GET_STACK_END(reg); \ - __GET_CURRENT(reg) + movq STACK_CPUINFO_FIELD(current_vcpu)(%r##reg), %r##reg #ifndef NDEBUG #define ASSERT_NOT_IN_ATOMIC \ -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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