Ring3: Placed UnicodeCollation driver into User space.

acidanthera · Jan 17, 2025 · 3f3f7fa · 3f3f7fa
1 parent cd65706
commit 3f3f7fa
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Showing 13 changed files with 182 additions and 96 deletions.
diff --git a/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S b/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S
@@ -90,6 +90,8 @@
   UINT64  ESR;    0x318   // Exception syndrome register
   UINT64  FAR;    0x320   // Fault Address Register
   UINT64  Type;   0x328   // Exception Type
+  UINT64  TTBR0;  0x330   // User Page Table
+  UINT64  Padding;0x338   // Alignment requirement
 */
 
 GCC_ASM_EXPORT(ExceptionHandlersEnd)
@@ -99,7 +101,7 @@ GCC_ASM_EXPORT(CommonCExceptionHandler)
 
 #define GP_CONTEXT_SIZE    (32 *  8)
 #define FP_CONTEXT_SIZE    (32 * 16)
-#define SYS_CONTEXT_SIZE   ( 6 *  8) // 5 SYS regs + Alignment requirement (ie: the stack must be aligned on 0x10)
+#define SYS_CONTEXT_SIZE   ( 8 *  8) // 7 SYS regs + Alignment requirement (ie: the stack must be aligned on 0x10)
 
 ASM_FUNC_ALIGN(ExceptionHandlerBase, 4096)
 
@@ -264,6 +266,11 @@ ASM_PFX(CommonExceptionEntry):
   stp      x2,  x3,  [x28, #-SYS_CONTEXT_SIZE]!
   stp      x4,  x5,  [x28, #0x10]
   stp      x6,  x0,  [x28, #0x20]
+  EL1_OR_EL2(x1)
+1:mrs      x2, ttbr0_el1
+  b        3f
+2:mrs      x2, ttbr0_el2
+3:stp      x2, xzr,  [x28, #0x30]
 
   // Push FP regs to Stack.
   stp      q0,  q1,  [x28, #-FP_CONTEXT_SIZE]!
@@ -288,17 +295,12 @@ ASM_PFX(CommonExceptionEntry):
   cmp      x2, 0           // Check whether EL0 process was interrupted
   b.ne     NoTTBR0Switch
   adrp     x1, ASM_PFX(CorePageTable)
+  ldr      x4, [x1]
   EL1_OR_EL2(x3)
-1:mrs      x4, ttbr0_el1
-  str      x4, [x1, #0x8]  // UserPageTable
-  ldr      x4, [x1]        // CorePageTable
-  msr      ttbr0_el1, x4
+1:msr      ttbr0_el1, x4
   tlbi     vmalle1
   b        3f
-2:mrs      x4, ttbr0_el2
-  str      x4, [x1, #0x8]  // UserPageTable
-  ldr      x4, [x1]        // CorePageTable
-  msr      ttbr0_el2, x4
+2:msr      ttbr0_el2, x4
   tlbi     alle2
 3:dsb      sy
   isb
@@ -324,14 +326,12 @@ NoTTBR0Switch:
   and      x2, x2, #0xF
   cmp      x2, 0           // Check whether EL0 process was interrupted
   b.ne     NoTTBR0Switch2
-  adrp     x1, ASM_PFX(CorePageTable)
+  ldr      x4, [x28, #(FP_CONTEXT_SIZE + 0x30)] // UserPageTable
   EL1_OR_EL2(x3)
-1:ldr      x4, [x1, #0x8]  // UserPageTable
-  msr      ttbr0_el1, x4
+1:msr      ttbr0_el1, x4
   tlbi     vmalle1
   b        3f
-2:ldr      x4, [x1, #0x8]  // UserPageTable
-  msr      ttbr0_el2, x4
+2:msr      ttbr0_el2, x4
   tlbi     alle2
 3:dsb      sy
   isb
@@ -428,9 +428,6 @@ ASM_FUNC(RegisterEl0Stack)
 ASM_PFX(CorePageTable):
 .ds.d 1
 
-UserPageTable:
-.ds.d 1
-
 .balign 4096
 Padding:
 .ds.b 1
diff --git a/ArmPkg/Library/ArmExceptionLib/Arm/ExceptionSupport.S b/ArmPkg/Library/ArmExceptionLib/Arm/ExceptionSupport.S
@@ -43,8 +43,11 @@ This is the stack constructed by the exception handler (low address to high addr
 
   LR    0x54    # SVC Link register (we need to restore it)
 
-  LR    0x58    # pushed by srsfd
-  CPSR  0x5c
+  TTBR0 0x58
+Padding 0x5c
+
+  LR    0x60    # pushed by srsfd
+  CPSR  0x64
 
  */
 
@@ -98,7 +101,7 @@ ASM_PFX(Fiq):
 ASM_PFX(ResetEntry):
   srsdb     #0x13!                    @ Store return state on SVC stack
                                       @ We are already in SVC mode
-
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -111,6 +114,7 @@ ASM_PFX(UndefinedInstructionEntry):
   sub       LR, LR, #4                @ Only -2 for Thumb, adjust in CommonExceptionEntry
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -124,6 +128,7 @@ ASM_PFX(SoftwareInterruptEntry):
   isb
   srsdb     #0x13!                    @ Store return state on SVC stack
                                       @ We are already in SVC mode
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -136,6 +141,7 @@ ASM_PFX(PrefetchAbortEntry):
   sub       LR,LR,#4
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -148,6 +154,7 @@ ASM_PFX(DataAbortEntry):
   sub       LR,LR,#8
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -159,6 +166,7 @@ ASM_PFX(DataAbortEntry):
 ASM_PFX(ReservedExceptionEntry):
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -171,6 +179,7 @@ ASM_PFX(IrqEntry):
   sub       LR,LR,#4
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -183,6 +192,7 @@ ASM_PFX(FiqEntry):
   sub       LR,LR,#4
   srsdb     #0x13!                    @ Store return state on SVC stack
   cps       #0x13                     @ Switch to SVC for common stack
+  sub       SP, SP, #0x8              @ Save space for TTBR0
   stmfd     SP!,{LR}                  @ Store the link register for the current mode
   sub       SP,SP,#0x20               @ Save space for SP, LR, PC, IFAR - CPSR
   stmfd     SP!,{R0-R12}              @ Store the register state
@@ -217,7 +227,7 @@ ASM_PFX(AsmCommonExceptionEntry):
   mrc       p15, 0, R1, c5, c0, 0   @ Read DFSR
   str       R1, [SP, #0x44]         @ Store it in EFI_SYSTEM_CONTEXT_ARM.DFSR
 
-  ldr       R1, [SP, #0x5c]         @ srsdb saved pre-exception CPSR on the stack
+  ldr       R1, [SP, #0x64]         @ srsdb saved pre-exception CPSR on the stack
   str       R1, [SP, #0x40]         @ Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
 
   add       R2, SP, #0x38           @ Make R2 point to EFI_SYSTEM_CONTEXT_ARM.LR
@@ -229,20 +239,20 @@ ASM_PFX(AsmCommonExceptionEntry):
   stmdaeq   R2, {sp}^               @   save unbanked sp
                                     @ else
   stmdane   R2, {lr}                @   save SVC lr
-  addne     R1, SP, #0x60           @   We pushed 0x60 bytes on the stack
+  addne     R1, SP, #0x68           @   We pushed 0x68 bytes on the stack
   strne     R1, [SP, #0x34]         @   Store it in EFI_SYSTEM_CONTEXT_ARM.SP
 
 
-  ldr       R5, [SP, #0x58]         @ PC is the LR pushed by srsfd
+  ldr       R5, [SP, #0x60]         @ PC is the LR pushed by srsfd
                                     @ Check to see if we have to adjust for Thumb entry
   sub       r4, r0, #1              @ if (ExceptionType == 1 || ExceptionType == 2)) {
   cmp       r4, #1                  @   // UND & SVC have different LR adjust for Thumb
   bhi       NoAdjustNeeded
 
-  ldr       R1, [SP, #0x5c]         @ srsdb saved pre-exception CPSR on the stack
+  ldr       R1, [SP, #0x64]         @ srsdb saved pre-exception CPSR on the stack
   tst       r1, #0x20               @   if ((CPSR & T)) == T) {  // Thumb Mode on entry
   addne     R5, R5, #2              @     PC += 2;
-  strne     R5,[SP,#0x58]           @ Update LR value pushed by srsfd
+  strne     R5,[SP,#0x60]           @ Update LR value pushed by srsfd
 
 NoAdjustNeeded:
 
@@ -260,8 +270,7 @@ NoAdjustNeeded:
   cmp       R5, 0                   @ Check whether EL0 process was interrupted
   bne       NoTTBR0Switch
   mrc       p15,0,R5,c2,c0,0        @ R5 == TTBR0
-  ADRL      (R6, UserPageTable)
-  str       R5, [R6]
+  str       R5, [SP, #0x58]
   and       R5, R5, #0x7F           @ Preserve TTBR0 attributes
   LDRL      (R6, ASM_PFX(CorePageTable))
   orr       R6, R6, R5              @ Assign TTBR0 attributes
@@ -296,7 +305,7 @@ CommonCExceptionHandler (
   and       R4, R4, #0xF
   cmp       R4, 0                   @ Check whether EL0 process was interrupted
   bne       NoTTBR0Switch2
-  LDRL      (R4, UserPageTable)
+  ldr       R4, [SP, #0x58]         @ User Page Table
   mcr       p15,0,R4,c2,c0,0        @ TTBR0 == R4
   mcr       p15,0,r0,c8,c7,0        @ TLBIALL, TLB Invalidate All.
   mcr       p15,0,r0,c7,c5,6        @ BPIALL, Branch Predictor Invalidate All.
@@ -325,6 +334,7 @@ NoTTBR0Switch2:
 
   add       SP,SP,#0x20             @ Clear out the remaining stack space
   ldmfd     SP!,{LR}                @ restore the link register for this context
+  add       SP, SP, #0x8            @ Clear out TTBR0 and Padding
   rfefd     SP!                     @ return from exception via srsfd stack slot
 
 ASM_FUNC_ALIGN(ExceptionHandlerFinal, 4096)
@@ -336,9 +346,6 @@ ASM_FUNC_ALIGN(ExceptionHandlerFinal, 4096)
 ASM_PFX(CorePageTable):
 .ds.l 1
 
-UserPageTable:
-.ds.l 1
-
 .balign 4096
 Padding:
 .ds.b 1
diff --git a/ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc b/ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc
@@ -90,7 +90,7 @@ APRIORI DXE {
   INF MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
   INF USER FatPkg/EnhancedFatDxe/Fat.inf
   INF USER MdeModulePkg/Core/Dxe/DxeRing3/DxeRing3.inf
-  INF MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
+  INF USER MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
   INF MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
   INF OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
 

diff --git a/MdeModulePkg/Core/Dxe/SysCall/AARCH64/CoreBootServices.S b/MdeModulePkg/Core/Dxe/SysCall/AARCH64/CoreBootServices.S
@@ -82,7 +82,8 @@ ASM_FUNC(ArmCallRing3)
   stp  q12, q13, [sp, #0xa0]
   stp  q14, q15, [sp, #0x80]
 
-  stp  xzr, x16, [sp, #0x70]
+  mrs  x6, sp_el0
+  stp  x6,  x16, [sp, #0x70]
   stp  x17, x18, [sp, #0x60]
   stp  x19, x20, [sp, #0x50]
   stp  x21, x22, [sp, #0x40]
@@ -138,7 +139,7 @@ ASM_FUNC(ReturnToCore)
   ldp  q12, q13, [sp, #0xa0]
   ldp  q14, q15, [sp, #0x80]
 
-  ldr  x16, [sp, #0x78]
+  ldp  x6,  x16, [sp, #0x70]
   ldp  x17, x18, [sp, #0x60]
   ldp  x19, x20, [sp, #0x50]
   ldp  x21, x22, [sp, #0x40]
@@ -147,6 +148,7 @@ ASM_FUNC(ReturnToCore)
   ldp  x27, x28, [sp, #0x10]
   ldp  x29, x30, [sp]
   add	 sp, sp, #0x100
+  msr  sp_el0, x6
   // Enable interrupts.
   msr  daifclr, #0xf
   isb

diff --git a/MdeModulePkg/Core/Dxe/SysCall/AARCH64/InitializeAARCH64.c b/MdeModulePkg/Core/Dxe/SysCall/AARCH64/InitializeAARCH64.c
@@ -12,8 +12,7 @@
 
 #include "DxeMain.h"
 
-STATIC UINTN  mSysCallStackTop;
-UINTN         gUserPageTable;
+UINTN  gUserPageTable;
 
 EFI_STATUS
 EFIAPI
@@ -156,8 +155,6 @@ CallRing3 (
   IN UINTN            *ReturnSP
   )
 {
-  mSysCallStackTop = SysCallStackTop;
-
   return ArmCallRing3 (
             Data,
             UserStackTop,

diff --git a/MdeModulePkg/Core/Dxe/SysCall/ARM/CoreBootServices.S b/MdeModulePkg/Core/Dxe/SysCall/ARM/CoreBootServices.S
@@ -76,6 +76,9 @@ ASM_FUNC(ArmCallRing3)
   ldr   R6, [SP, #0x28]
   // R7 is gUserPageTable
   ldr   R7, [SP, #0x2C]
+  // Save old SP_usr on Core Stack.
+  sub   SP, SP, #0x8
+  stmia SP, {SP}^
 
 #if (FixedPcdGet32(PcdVFPEnabled))
   // Save vstm registers in case they are used in optimizations.
@@ -135,6 +138,10 @@ ASM_FUNC(ReturnToCore)
   vpop  {d0-d15}
 #endif
 
+  // Restore old SP_usr.
+  ldmia SP, {SP}^
+  add   SP, SP, #0x8
+
   pop   {R4-R12, LR}
 
   // Enable interrupts.

diff --git a/MdeModulePkg/Core/Dxe/SysCall/ARM/InitializeARM.c b/MdeModulePkg/Core/Dxe/SysCall/ARM/InitializeARM.c
@@ -11,8 +11,7 @@
 
 #include "DxeMain.h"
 
-STATIC UINTN  mSysCallStackTop;
-UINTN         gUserPageTable;
+UINTN  gUserPageTable;
 
 EFI_STATUS
 EFIAPI
@@ -151,8 +150,6 @@ CallRing3 (
   IN UINTN            *ReturnSP
   )
 {
-  mSysCallStackTop = SysCallStackTop;
-
   return ArmCallRing3 (
             Data,
             UserStackTop,

diff --git a/MdeModulePkg/Core/Dxe/SysCall/IA32/CoreBootServices.nasm b/MdeModulePkg/Core/Dxe/SysCall/IA32/CoreBootServices.nasm
@@ -180,24 +180,27 @@ ASM_PFX(CallRing3):
     push    ebp
     push    edi
     push    esi
+    ; Save old SysCallStackTop.
+    push dword MSR_IA32_SYSENTER_ESP
+    call ASM_PFX(AsmReadMsr64)
+    pop     ebx
+    push    eax
 
     ; Save Core Stack pointer.
-    mov     ebx, [esp + 4 * 8] ; ReturnSP
+    mov     ebx, [esp + 4 * 9] ; ReturnSP
     mov     [ebx], esp
 
-    mov     ebx, [esp + 4 * 7]
-    mov     [ASM_PFX(SysCallStackTop)], ebx
     mov     edx, 0
-    mov     eax, ebx
+    mov     eax, [esp + 4 * 8] ; SysCallStackTop
     mov     ecx, MSR_IA32_SYSENTER_ESP
     wrmsr
 
     SetRing3DataSegmentSelectors
 
     ; Prepare SYSEXIT arguments.
-    mov     ecx, [esp + 4 * 6] ; UserStackTop
+    mov     ecx, [esp + 4 * 7] ; UserStackTop
     mov     edx, [ASM_PFX(gRing3EntryPoint)]
-    mov     eax, [esp + 4 * 5] ; Data
+    mov     eax, [esp + 4 * 6] ; Data
 
     ; Switch to User Stack.
     mov     ebp, ecx
@@ -223,8 +226,15 @@ ASM_PFX(SysCallEnd):
 ;------------------------------------------------------------------------------
 global ASM_PFX(ReturnToCore)
 ASM_PFX(ReturnToCore):
-    mov     eax, [esp + 4]   ; Status
+    mov     ebx, [esp + 4]   ; Status
     mov     esp, [esp + 4*2] ; ReturnSP
+    ; Restore old SysCallStackTop.
+    mov     edx, 0
+    pop     eax
+    mov     ecx, MSR_IA32_SYSENTER_ESP
+    wrmsr
+
+    mov     eax, ebx
     pop     esi
     pop     edi
     pop     ebp
@@ -245,5 +255,5 @@ ASM_PFX(gUserPageTable):
   resd 1
 
 ALIGN   4096
-ASM_PFX(SysCallStackTop):
+Padding:
   resd 1