Changeset 32573ff in mainline for kernel/arch/amd64/src/asm.S

Timestamp:

2016-05-02T20:58:16Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

7c4b26c

Parents:

6adb775f (diff), 5035ba05 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline, which has dltest and fixes.

File:

• kernel/arch/amd64/src/asm.S (modified) (6 diffs)

kernel/arch/amd64/src/asm.S

@@ -31 +31 @@
 #include <arch/mm/page.h>
 #include <arch/istate_struct.h>
+#include <arch/kseg_struct.h>
+#include <arch/cpu.h>
 
 .text
@@ -178 +180 @@
                 subq $(ISTATE_SOFT_SIZE + 8), %rsp
         .endif
-        
+
         /*
          * Save the general purpose registers.
@@ -199 +201 @@
 
         /*
+         * Is this trap from the kernel?
+         */
+        cmpq $(GDT_SELECTOR(KTEXT_DES)), ISTATE_OFFSET_CS(%rsp)
+        jz 0f
+
+        /*
+         * Switch to kernel FS base.
+         */
+        swapgs
+        movl $AMD_MSR_FS, %ecx
+        movl %gs:KSEG_OFFSET_FSBASE, %eax
+        movl %gs:KSEG_OFFSET_FSBASE+4, %edx
+        wrmsr
+        swapgs
+
+        /*
          * Imitate a regular stack frame linkage.
          * Stop stack traces here if we came from userspace.
          */
-        xorl %edx, %edx
-        cmpq $(GDT_SELECTOR(KTEXT_DES)), ISTATE_OFFSET_CS(%rsp)
+0:      movl $0x0, %edx
         cmovnzq %rdx, %rbp
 
@@ -272 +289 @@
         swapgs
         
-        /*
-         * %gs:0 Scratch space for this thread's user RSP
-         * %gs:8 Address to be used as this thread's kernel RSP
-         */
-        
-        movq %rsp, %gs:0  /* save this thread's user RSP */
-        movq %gs:8, %rsp  /* set this thread's kernel RSP */
-        
+        movq %rsp, %gs:KSEG_OFFSET_USTACK_RSP  /* save this thread's user RSP */
+        movq %gs:KSEG_OFFSET_KSTACK_RSP, %rsp  /* set this thread's kernel RSP */
+
         /*
          * Note that the space needed for the imitated istate structure has been
@@ -308 +320 @@
 
         /*
+         * Switch to kernel FS base.
+         */
+        movl $AMD_MSR_FS, %ecx
+        movl %gs:KSEG_OFFSET_FSBASE, %eax
+        movl %gs:KSEG_OFFSET_FSBASE+4, %edx
+        wrmsr
+        movq ISTATE_OFFSET_RDX(%rsp), %rdx      /* restore 3rd argument */
+
+        /*
          * Save the return address and the userspace stack on locations that
          * would normally be taken by them.
          */
-        movq %gs:0, %rax
+        movq %gs:KSEG_OFFSET_USTACK_RSP, %rax
         movq %rax, ISTATE_OFFSET_RSP(%rsp)
         movq %rcx, ISTATE_OFFSET_RIP(%rsp)
@@ -325 +346 @@
         swapgs
         sti
-        
+
         /* Copy the 4th argument where it is expected  */
         movq %r10, %rcx