diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-14 13:34:37 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-14 13:34:37 -0700 |
commit | 0520058d0578c2924b1571c16281f873cb4a3d2b (patch) | |
tree | d59fa88120a43dc90ec631508a0cbe13dc80e3ef /arch/x86/entry | |
parent | cd94257d7a8103acf136e4bd46e3d0ad698a6f3d (diff) | |
parent | 585c6ed738a5ed2a6fd7662fa1d82f25acfa85de (diff) |
Merge tag 'for-linus-5.9-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull more xen updates from Juergen Gross:
- Remove support for running as 32-bit Xen PV-guest.
32-bit PV guests are rarely used, are lacking security fixes for
Meltdown, and can be easily replaced by PVH mode. Another series for
doing more cleanup will follow soon (removal of 32-bit-only pvops
functionality).
- Fixes and additional features for the Xen display frontend driver.
* tag 'for-linus-5.9-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
drm/xen-front: Pass dumb buffer data offset to the backend
xen: Sync up with the canonical protocol definition in Xen
drm/xen-front: Add YUYV to supported formats
drm/xen-front: Fix misused IS_ERR_OR_NULL checks
xen/gntdev: Fix dmabuf import with non-zero sgt offset
x86/xen: drop tests for highmem in pv code
x86/xen: eliminate xen-asm_64.S
x86/xen: remove 32-bit Xen PV guest support
Diffstat (limited to 'arch/x86/entry')
-rw-r--r-- | arch/x86/entry/entry_32.S | 109 | ||||
-rw-r--r-- | arch/x86/entry/vdso/vdso32/note.S | 30 |
2 files changed, 2 insertions, 137 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 29b7d52143e9..df8c017e6161 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -449,8 +449,6 @@ .macro SWITCH_TO_KERNEL_STACK - ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV - BUG_IF_WRONG_CR3 SWITCH_TO_KERNEL_CR3 scratch_reg=%eax @@ -599,8 +597,6 @@ */ .macro SWITCH_TO_ENTRY_STACK - ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV - /* Bytes to copy */ movl $PTREGS_SIZE, %ecx @@ -872,17 +868,6 @@ SYM_ENTRY(__begin_SYSENTER_singlestep_region, SYM_L_GLOBAL, SYM_A_NONE) * will ignore all of the single-step traps generated in this range. */ -#ifdef CONFIG_XEN_PV -/* - * Xen doesn't set %esp to be precisely what the normal SYSENTER - * entry point expects, so fix it up before using the normal path. - */ -SYM_CODE_START(xen_sysenter_target) - addl $5*4, %esp /* remove xen-provided frame */ - jmp .Lsysenter_past_esp -SYM_CODE_END(xen_sysenter_target) -#endif - /* * 32-bit SYSENTER entry. * @@ -965,9 +950,8 @@ SYM_FUNC_START(entry_SYSENTER_32) movl %esp, %eax call do_SYSENTER_32 - /* XEN PV guests always use IRET path */ - ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \ - "jmp .Lsyscall_32_done", X86_FEATURE_XENPV + testl %eax, %eax + jz .Lsyscall_32_done STACKLEAK_ERASE @@ -1165,95 +1149,6 @@ SYM_FUNC_END(entry_INT80_32) #endif .endm -#ifdef CONFIG_PARAVIRT -SYM_CODE_START(native_iret) - iret - _ASM_EXTABLE(native_iret, asm_iret_error) -SYM_CODE_END(native_iret) -#endif - -#ifdef CONFIG_XEN_PV -/* - * See comment in entry_64.S for further explanation - * - * Note: This is not an actual IDT entry point. It's a XEN specific entry - * point and therefore named to match the 64-bit trampoline counterpart. - */ -SYM_FUNC_START(xen_asm_exc_xen_hypervisor_callback) - /* - * Check to see if we got the event in the critical - * region in xen_iret_direct, after we've reenabled - * events and checked for pending events. This simulates - * iret instruction's behaviour where it delivers a - * pending interrupt when enabling interrupts: - */ - cmpl $xen_iret_start_crit, (%esp) - jb 1f - cmpl $xen_iret_end_crit, (%esp) - jae 1f - call xen_iret_crit_fixup -1: - pushl $-1 /* orig_ax = -1 => not a system call */ - SAVE_ALL - ENCODE_FRAME_POINTER - - mov %esp, %eax - call xen_pv_evtchn_do_upcall - jmp handle_exception_return -SYM_FUNC_END(xen_asm_exc_xen_hypervisor_callback) - -/* - * Hypervisor uses this for application faults while it executes. - * We get here for two reasons: - * 1. Fault while reloading DS, ES, FS or GS - * 2. Fault while executing IRET - * Category 1 we fix up by reattempting the load, and zeroing the segment - * register if the load fails. - * Category 2 we fix up by jumping to do_iret_error. We cannot use the - * normal Linux return path in this case because if we use the IRET hypercall - * to pop the stack frame we end up in an infinite loop of failsafe callbacks. - * We distinguish between categories by maintaining a status value in EAX. - */ -SYM_FUNC_START(xen_failsafe_callback) - pushl %eax - movl $1, %eax -1: mov 4(%esp), %ds -2: mov 8(%esp), %es -3: mov 12(%esp), %fs -4: mov 16(%esp), %gs - /* EAX == 0 => Category 1 (Bad segment) - EAX != 0 => Category 2 (Bad IRET) */ - testl %eax, %eax - popl %eax - lea 16(%esp), %esp - jz 5f - jmp asm_iret_error -5: pushl $-1 /* orig_ax = -1 => not a system call */ - SAVE_ALL - ENCODE_FRAME_POINTER - jmp handle_exception_return - -.section .fixup, "ax" -6: xorl %eax, %eax - movl %eax, 4(%esp) - jmp 1b -7: xorl %eax, %eax - movl %eax, 8(%esp) - jmp 2b -8: xorl %eax, %eax - movl %eax, 12(%esp) - jmp 3b -9: xorl %eax, %eax - movl %eax, 16(%esp) - jmp 4b -.previous - _ASM_EXTABLE(1b, 6b) - _ASM_EXTABLE(2b, 7b) - _ASM_EXTABLE(3b, 8b) - _ASM_EXTABLE(4b, 9b) -SYM_FUNC_END(xen_failsafe_callback) -#endif /* CONFIG_XEN_PV */ - SYM_CODE_START_LOCAL_NOALIGN(handle_exception) /* the function address is in %gs's slot on the stack */ SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1 diff --git a/arch/x86/entry/vdso/vdso32/note.S b/arch/x86/entry/vdso/vdso32/note.S index e78047d119f6..2cbd39939dc6 100644 --- a/arch/x86/entry/vdso/vdso32/note.S +++ b/arch/x86/entry/vdso/vdso32/note.S @@ -16,33 +16,3 @@ ELFNOTE_START(Linux, 0, "a") ELFNOTE_END BUILD_SALT - -#ifdef CONFIG_XEN -/* - * Add a special note telling glibc's dynamic linker a fake hardware - * flavor that it will use to choose the search path for libraries in the - * same way it uses real hardware capabilities like "mmx". - * We supply "nosegneg" as the fake capability, to indicate that we - * do not like negative offsets in instructions using segment overrides, - * since we implement those inefficiently. This makes it possible to - * install libraries optimized to avoid those access patterns in someplace - * like /lib/i686/tls/nosegneg. Note that an /etc/ld.so.conf.d/file - * corresponding to the bits here is needed to make ldconfig work right. - * It should contain: - * hwcap 1 nosegneg - * to match the mapping of bit to name that we give here. - * - * At runtime, the fake hardware feature will be considered to be present - * if its bit is set in the mask word. So, we start with the mask 0, and - * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen. - */ - -#include "../../xen/vdso.h" /* Defines VDSO_NOTE_NONEGSEG_BIT. */ - -ELFNOTE_START(GNU, 2, "a") - .long 1 /* ncaps */ -VDSO32_NOTE_MASK: /* Symbol used by arch/x86/xen/setup.c */ - .long 0 /* mask */ - .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */ -ELFNOTE_END -#endif |