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Diffstat (limited to 'arch/x86_64/ia32/ptrace32.c')
-rw-r--r--arch/x86_64/ia32/ptrace32.c59
1 files changed, 20 insertions, 39 deletions
diff --git a/arch/x86_64/ia32/ptrace32.c b/arch/x86_64/ia32/ptrace32.c
index 2a925e2af39..23a4515a73b 100644
--- a/arch/x86_64/ia32/ptrace32.c
+++ b/arch/x86_64/ia32/ptrace32.c
@@ -28,9 +28,12 @@
#include <asm/i387.h>
#include <asm/fpu32.h>
-/* determines which flags the user has access to. */
-/* 1 = access 0 = no access */
-#define FLAG_MASK 0x44dd5UL
+/*
+ * Determines which flags the user has access to [1 = access, 0 = no access].
+ * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
+ * Also masks reserved bits (31-22, 15, 5, 3, 1).
+ */
+#define FLAG_MASK 0x54dd5UL
#define R32(l,q) \
case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
@@ -38,7 +41,7 @@
static int putreg32(struct task_struct *child, unsigned regno, u32 val)
{
int i;
- __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
+ __u64 *stack = (__u64 *)task_pt_regs(child);
switch (regno) {
case offsetof(struct user32, regs.fs):
@@ -134,7 +137,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
{
- __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
+ __u64 *stack = (__u64 *)task_pt_regs(child);
switch (regno) {
case offsetof(struct user32, regs.fs):
@@ -196,36 +199,6 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
#undef R32
-static struct task_struct *find_target(int request, int pid, int *err)
-{
- struct task_struct *child;
-
- *err = -EPERM;
- if (pid == 1)
- return NULL;
-
- *err = -ESRCH;
- read_lock(&tasklist_lock);
- child = find_task_by_pid(pid);
- if (child)
- get_task_struct(child);
- read_unlock(&tasklist_lock);
- if (child) {
- *err = -EPERM;
- if (child->pid == 1)
- goto out;
- *err = ptrace_check_attach(child, request == PTRACE_KILL);
- if (*err < 0)
- goto out;
- return child;
- }
- out:
- if (child)
- put_task_struct(child);
- return NULL;
-
-}
-
asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
{
struct task_struct *child;
@@ -254,11 +227,18 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
break;
}
- child = find_target(request, pid, &ret);
- if (!child)
- return ret;
+ if (request == PTRACE_TRACEME)
+ return ptrace_traceme();
+
+ child = ptrace_get_task_struct(pid);
+ if (IS_ERR(child))
+ return PTR_ERR(child);
- childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
+ ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ if (ret < 0)
+ goto out;
+
+ childregs = task_pt_regs(child);
switch (request) {
case PTRACE_PEEKDATA:
@@ -373,6 +353,7 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
break;
}
+ out:
put_task_struct(child);
return ret;
}