diff options
| author | Andy Lutomirski <luto@kernel.org> | 2021-02-13 20:19:45 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-03-08 13:27:31 +0100 |
| commit | d0962f2b24c99889a386f0658c71535f56358f77 (patch) | |
| tree | 60557e89cb7b3e4e2b0a95e44a54025661a9d8e3 /arch/x86/entry/entry_32.S | |
| parent | x86/stackprotector/32: Make the canary into a regular percpu variable (diff) | |
| download | linux-d0962f2b24c99889a386f0658c71535f56358f77.tar.xz linux-d0962f2b24c99889a386f0658c71535f56358f77.zip | |
x86/entry/32: Remove leftover macros after stackprotector cleanups
Now that nonlazy-GS mode is gone, remove the macros from entry_32.S
that obfuscated^Wabstracted GS handling. The assembled output is
identical before and after this patch.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/b1543116f0f0e68f1763d90d5f7fcec27885dff5.1613243844.git.luto@kernel.org
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 43 |
1 files changed, 2 insertions, 41 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index eb0cb662bca5..bee9101e211e 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -53,35 +53,6 @@ #define PTI_SWITCH_MASK (1 << PAGE_SHIFT) -/* - * User gs save/restore - * - * This is leftover junk from CONFIG_X86_32_LAZY_GS. A subsequent patch - * will remove it entirely. - */ - /* unfortunately push/pop can't be no-op */ -.macro PUSH_GS - pushl $0 -.endm -.macro POP_GS pop=0 - addl $(4 + \pop), %esp -.endm -.macro POP_GS_EX -.endm - - /* all the rest are no-op */ -.macro PTGS_TO_GS -.endm -.macro PTGS_TO_GS_EX -.endm -.macro GS_TO_REG reg -.endm -.macro REG_TO_PTGS reg -.endm -.macro SET_KERNEL_GS reg -.endm - - /* Unconditionally switch to user cr3 */ .macro SWITCH_TO_USER_CR3 scratch_reg:req ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI @@ -234,7 +205,7 @@ .macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 unwind_espfix=0 cld .if \skip_gs == 0 - PUSH_GS + pushl $0 .endif pushl %fs @@ -259,9 +230,6 @@ movl $(__USER_DS), %edx movl %edx, %ds movl %edx, %es -.if \skip_gs == 0 - SET_KERNEL_GS %edx -.endif /* Switch to kernel stack if necessary */ .if \switch_stacks > 0 SWITCH_TO_KERNEL_STACK @@ -300,7 +268,7 @@ 1: popl %ds 2: popl %es 3: popl %fs - POP_GS \pop + addl $(4 + \pop), %esp /* pop the unused "gs" slot */ IRET_FRAME .pushsection .fixup, "ax" 4: movl $0, (%esp) @@ -313,7 +281,6 @@ _ASM_EXTABLE(1b, 4b) _ASM_EXTABLE(2b, 5b) _ASM_EXTABLE(3b, 6b) - POP_GS_EX .endm .macro RESTORE_ALL_NMI cr3_reg:req pop=0 @@ -928,7 +895,6 @@ SYM_FUNC_START(entry_SYSENTER_32) movl PT_EIP(%esp), %edx /* pt_regs->ip */ movl PT_OLDESP(%esp), %ecx /* pt_regs->sp */ 1: mov PT_FS(%esp), %fs - PTGS_TO_GS popl %ebx /* pt_regs->bx */ addl $2*4, %esp /* skip pt_regs->cx and pt_regs->dx */ @@ -964,7 +930,6 @@ SYM_FUNC_START(entry_SYSENTER_32) jmp 1b .popsection _ASM_EXTABLE(1b, 2b) - PTGS_TO_GS_EX .Lsysenter_fix_flags: pushl $X86_EFLAGS_FIXED @@ -1106,11 +1071,7 @@ SYM_CODE_START_LOCAL_NOALIGN(handle_exception) SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1 ENCODE_FRAME_POINTER - /* fixup %gs */ - GS_TO_REG %ecx movl PT_GS(%esp), %edi # get the function address - REG_TO_PTGS %ecx - SET_KERNEL_GS %ecx /* fixup orig %eax */ movl PT_ORIG_EAX(%esp), %edx # get the error code |