diff options
Diffstat (limited to 'main/xen/xsa213-4.6.patch')
| -rw-r--r-- | main/xen/xsa213-4.6.patch | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/main/xen/xsa213-4.6.patch b/main/xen/xsa213-4.6.patch deleted file mode 100644 index 115bb6310b..0000000000 --- a/main/xen/xsa213-4.6.patch +++ /dev/null @@ -1,173 +0,0 @@ -From: Jan Beulich <jbeulich@suse.com> -Subject: multicall: deal with early exit conditions - -In particular changes to guest privilege level require the multicall -sequence to be aborted, as hypercalls are permitted from kernel mode -only. While likely not very useful in a multicall, also properly handle -the return value in the HYPERVISOR_iret case (which should be the guest -specified value). - -This is XSA-213. - -Reported-by: Jann Horn <jannh@google.com> -Signed-off-by: Jan Beulich <jbeulich@suse.com> -Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> -Acked-by: Julien Grall <julien.grall@arm.com> - ---- a/xen/arch/arm/traps.c -+++ b/xen/arch/arm/traps.c -@@ -1485,30 +1485,33 @@ static bool_t check_multicall_32bit_clea - return true; - } - --void do_multicall_call(struct multicall_entry *multi) -+enum mc_disposition do_multicall_call(struct multicall_entry *multi) - { - arm_hypercall_fn_t call = NULL; - - if ( multi->op >= ARRAY_SIZE(arm_hypercall_table) ) - { - multi->result = -ENOSYS; -- return; -+ return mc_continue; - } - - call = arm_hypercall_table[multi->op].fn; - if ( call == NULL ) - { - multi->result = -ENOSYS; -- return; -+ return mc_continue; - } - - if ( is_32bit_domain(current->domain) && - !check_multicall_32bit_clean(multi) ) -- return; -+ return mc_continue; - - multi->result = call(multi->args[0], multi->args[1], - multi->args[2], multi->args[3], - multi->args[4]); -+ -+ return likely(!psr_mode_is_user(guest_cpu_user_regs())) -+ ? mc_continue : mc_preempt; - } - - /* ---- a/xen/common/multicall.c -+++ b/xen/common/multicall.c -@@ -40,6 +40,7 @@ do_multicall( - struct mc_state *mcs = ¤t->mc_state; - uint32_t i; - int rc = 0; -+ enum mc_disposition disp = mc_continue; - - if ( unlikely(__test_and_set_bit(_MCSF_in_multicall, &mcs->flags)) ) - { -@@ -50,7 +51,7 @@ do_multicall( - if ( unlikely(!guest_handle_okay(call_list, nr_calls)) ) - rc = -EFAULT; - -- for ( i = 0; !rc && i < nr_calls; i++ ) -+ for ( i = 0; !rc && disp == mc_continue && i < nr_calls; i++ ) - { - if ( i && hypercall_preempt_check() ) - goto preempted; -@@ -63,7 +64,7 @@ do_multicall( - - trace_multicall_call(&mcs->call); - -- do_multicall_call(&mcs->call); -+ disp = do_multicall_call(&mcs->call); - - #ifndef NDEBUG - { -@@ -77,7 +78,14 @@ do_multicall( - } - #endif - -- if ( unlikely(__copy_field_to_guest(call_list, &mcs->call, result)) ) -+ if ( unlikely(disp == mc_exit) ) -+ { -+ if ( __copy_field_to_guest(call_list, &mcs->call, result) ) -+ /* nothing, best effort only */; -+ rc = mcs->call.result; -+ } -+ else if ( unlikely(__copy_field_to_guest(call_list, &mcs->call, -+ result)) ) - rc = -EFAULT; - else if ( test_bit(_MCSF_call_preempted, &mcs->flags) ) - { -@@ -93,6 +101,9 @@ do_multicall( - guest_handle_add_offset(call_list, 1); - } - -+ if ( unlikely(disp == mc_preempt) && i < nr_calls ) -+ goto preempted; -+ - perfc_incr(calls_to_multicall); - perfc_add(calls_from_multicall, i); - mcs->flags = 0; ---- a/xen/include/asm-arm/multicall.h -+++ b/xen/include/asm-arm/multicall.h -@@ -1,7 +1,11 @@ - #ifndef __ASM_ARM_MULTICALL_H__ - #define __ASM_ARM_MULTICALL_H__ - --extern void do_multicall_call(struct multicall_entry *call); -+extern enum mc_disposition { -+ mc_continue, -+ mc_exit, -+ mc_preempt, -+} do_multicall_call(struct multicall_entry *call); - - #endif /* __ASM_ARM_MULTICALL_H__ */ - /* ---- a/xen/include/asm-x86/multicall.h -+++ b/xen/include/asm-x86/multicall.h -@@ -7,8 +7,21 @@ - - #include <xen/errno.h> - -+enum mc_disposition { -+ mc_continue, -+ mc_exit, -+ mc_preempt, -+}; -+ -+#define multicall_ret(call) \ -+ (unlikely((call)->op == __HYPERVISOR_iret) \ -+ ? mc_exit \ -+ : likely(guest_kernel_mode(current, \ -+ guest_cpu_user_regs())) \ -+ ? mc_continue : mc_preempt) -+ - #define do_multicall_call(_call) \ -- do { \ -+ ({ \ - __asm__ __volatile__ ( \ - " movq %c1(%0),%%rax; " \ - " leaq hypercall_table(%%rip),%%rdi; " \ -@@ -37,9 +50,11 @@ - /* all the caller-saves registers */ \ - : "rax", "rcx", "rdx", "rsi", "rdi", \ - "r8", "r9", "r10", "r11" ); \ -- } while ( 0 ) -+ multicall_ret(_call); \ -+ }) - - #define compat_multicall_call(_call) \ -+ ({ \ - __asm__ __volatile__ ( \ - " movl %c1(%0),%%eax; " \ - " leaq compat_hypercall_table(%%rip),%%rdi; "\ -@@ -67,6 +82,8 @@ - "i" (-ENOSYS) \ - /* all the caller-saves registers */ \ - : "rax", "rcx", "rdx", "rsi", "rdi", \ -- "r8", "r9", "r10", "r11" ) \ -+ "r8", "r9", "r10", "r11" ); \ -+ multicall_ret(_call); \ -+ }) - - #endif /* __ASM_X86_MULTICALL_H__ */ |