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-rw-r--r--arch/x86/um/shared/sysdep/stub_32.h33
-rw-r--r--arch/x86/um/shared/sysdep/stub_64.h36
-rw-r--r--arch/x86/um/stub_32.S17
-rw-r--r--arch/x86/um/stub_64.S5
-rw-r--r--arch/x86/um/stub_segv.c5
5 files changed, 62 insertions, 34 deletions
diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h
index 8ea69211e53c..c3891c1ada26 100644
--- a/arch/x86/um/shared/sysdep/stub_32.h
+++ b/arch/x86/um/shared/sysdep/stub_32.h
@@ -7,8 +7,8 @@
#define __SYSDEP_STUB_H
#include <asm/ptrace.h>
+#include <generated/asm-offsets.h>
-#define STUB_SYSCALL_RET EAX
#define STUB_MMAP_NR __NR_mmap2
#define MMAP_OFFSET(o) ((o) >> UM_KERN_PAGE_SHIFT)
@@ -77,17 +77,28 @@ static inline void trap_myself(void)
__asm("int3");
}
-static inline void remap_stack(int fd, unsigned long offset)
+static void inline remap_stack_and_trap(void)
{
- __asm__ volatile ("movl %%eax,%%ebp ; movl %0,%%eax ; int $0x80 ;"
- "movl %7, %%ebx ; movl %%eax, (%%ebx)"
- : : "g" (STUB_MMAP_NR), "b" (STUB_DATA),
- "c" (UM_KERN_PAGE_SIZE),
- "d" (PROT_READ | PROT_WRITE),
- "S" (MAP_FIXED | MAP_SHARED), "D" (fd),
- "a" (offset),
- "i" (&((struct stub_data *) STUB_DATA)->child_err)
- : "memory");
+ __asm__ volatile (
+ "movl %%esp,%%ebx ;"
+ "andl %0,%%ebx ;"
+ "movl %1,%%eax ;"
+ "movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;"
+ "movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;"
+ "int $0x80 ;"
+ "addl %4,%%ebx ; movl %%eax, (%%ebx) ;"
+ "int $3"
+ : :
+ "g" (~(UM_KERN_PAGE_SIZE - 1)),
+ "g" (STUB_MMAP_NR),
+ "g" (UML_STUB_FIELD_FD),
+ "g" (UML_STUB_FIELD_OFFSET),
+ "g" (UML_STUB_FIELD_CHILD_ERR),
+ "c" (UM_KERN_PAGE_SIZE),
+ "d" (PROT_READ | PROT_WRITE),
+ "S" (MAP_FIXED | MAP_SHARED)
+ :
+ "memory");
}
#endif
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
index b7b8b8e4359d..6e2626b77a2e 100644
--- a/arch/x86/um/shared/sysdep/stub_64.h
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -7,8 +7,8 @@
#define __SYSDEP_STUB_H
#include <sysdep/ptrace_user.h>
+#include <generated/asm-offsets.h>
-#define STUB_SYSCALL_RET PT_INDEX(RAX)
#define STUB_MMAP_NR __NR_mmap
#define MMAP_OFFSET(o) (o)
@@ -82,18 +82,30 @@ static inline void trap_myself(void)
__asm("int3");
}
-static inline void remap_stack(long fd, unsigned long offset)
+static inline void remap_stack_and_trap(void)
{
- __asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
- "movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
- "movq %%rax, (%%rbx)":
- : "a" (STUB_MMAP_NR), "D" (STUB_DATA),
- "S" (UM_KERN_PAGE_SIZE),
- "d" (PROT_READ | PROT_WRITE),
- "g" (MAP_FIXED | MAP_SHARED), "g" (fd),
- "g" (offset),
- "i" (&((struct stub_data *) STUB_DATA)->child_err)
- : __syscall_clobber, "r10", "r8", "r9" );
+ __asm__ volatile (
+ "movq %0,%%rax ;"
+ "movq %%rsp,%%rdi ;"
+ "andq %1,%%rdi ;"
+ "movq %2,%%r10 ;"
+ "movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
+ "movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
+ __syscall ";"
+ "movq %%rsp,%%rdi ; andq %1,%%rdi ;"
+ "addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
+ "int3"
+ : :
+ "g" (STUB_MMAP_NR),
+ "g" (~(UM_KERN_PAGE_SIZE - 1)),
+ "g" (MAP_FIXED | MAP_SHARED),
+ "g" (UML_STUB_FIELD_FD),
+ "g" (UML_STUB_FIELD_OFFSET),
+ "g" (UML_STUB_FIELD_CHILD_ERR),
+ "S" (UM_KERN_PAGE_SIZE),
+ "d" (PROT_READ | PROT_WRITE)
+ :
+ __syscall_clobber, "r10", "r8", "r9");
}
#endif
diff --git a/arch/x86/um/stub_32.S b/arch/x86/um/stub_32.S
index a193e88536a9..8291899e6aaf 100644
--- a/arch/x86/um/stub_32.S
+++ b/arch/x86/um/stub_32.S
@@ -5,21 +5,22 @@
.globl batch_syscall_stub
batch_syscall_stub:
- /* load pointer to first operation */
- mov $(STUB_DATA+8), %esp
-
+ /* %esp comes in as "top of page" */
+ mov %esp, %ecx
+ /* %esp has pointer to first operation */
+ add $8, %esp
again:
/* load length of additional data */
mov 0x0(%esp), %eax
/* if(length == 0) : end of list */
/* write possible 0 to header */
- mov %eax, STUB_DATA+4
+ mov %eax, 0x4(%ecx)
cmpl $0, %eax
jz done
/* save current pointer */
- mov %esp, STUB_DATA+4
+ mov %esp, 0x4(%ecx)
/* skip additional data */
add %eax, %esp
@@ -38,6 +39,10 @@ again:
/* execute syscall */
int $0x80
+ /* restore top of page pointer in %ecx */
+ mov %esp, %ecx
+ andl $(~UM_KERN_PAGE_SIZE) + 1, %ecx
+
/* check return value */
pop %ebx
cmp %ebx, %eax
@@ -45,7 +50,7 @@ again:
done:
/* save return value */
- mov %eax, STUB_DATA
+ mov %eax, (%ecx)
/* stop */
int3
diff --git a/arch/x86/um/stub_64.S b/arch/x86/um/stub_64.S
index 8a95c5b2eaf9..f3404640197a 100644
--- a/arch/x86/um/stub_64.S
+++ b/arch/x86/um/stub_64.S
@@ -4,9 +4,8 @@
.section .__syscall_stub, "ax"
.globl batch_syscall_stub
batch_syscall_stub:
- mov $(STUB_DATA), %rbx
- /* load pointer to first operation */
- mov %rbx, %rsp
+ /* %rsp has the pointer to first operation */
+ mov %rsp, %rbx
add $0x10, %rsp
again:
/* load length of additional data */
diff --git a/arch/x86/um/stub_segv.c b/arch/x86/um/stub_segv.c
index 27361cbb7ca9..21836eaf1725 100644
--- a/arch/x86/um/stub_segv.c
+++ b/arch/x86/um/stub_segv.c
@@ -11,10 +11,11 @@
void __attribute__ ((__section__ (".__syscall_stub")))
stub_segv_handler(int sig, siginfo_t *info, void *p)
{
+ int stack;
ucontext_t *uc = p;
+ struct faultinfo *f = (void *)(((unsigned long)&stack) & ~(UM_KERN_PAGE_SIZE - 1));
- GET_FAULTINFO_FROM_MC(*((struct faultinfo *) STUB_DATA),
- &uc->uc_mcontext);
+ GET_FAULTINFO_FROM_MC(*f, &uc->uc_mcontext);
trap_myself();
}
generated by cgit (git 2.34.1) at 2024-06-12 20:08:35 +0000