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elf: don't hash userspace addresses

PATCH In review Alexey Dobriyan 2 participants 5 messages May 4, 2018 – May 9, 2018

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#0 lore raw

PATCH 1/1 elf: don't hash userspace addresses

---

 fs/binfmt_elf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
fs/binfmt_elf.c +2 -2
@@ -379,8 +379,8 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 
 	if ((type & MAP_FIXED_NOREPLACE) &&
 	    PTR_ERR((void *)map_addr) == -EEXIST)
-		pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
-			task_pid_nr(current), current->comm, (void *)addr);
+		pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the memory is mapped already\n",
+			task_pid_nr(current), current->comm, addr);
 
 	return(map_addr);
 }
#1 lore raw
Quoted 9 lines · Alexey Dobriyan

---

 fs/binfmt_elf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

fs/binfmt_elf.c static unsigned long elf_map(struct file *filep, unsigned long addr, · line 383

Quoted 7 lines
fs/binfmt_elf.c +2 -2
@@ -379,8 +379,8 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 
 	if ((type & MAP_FIXED_NOREPLACE) &&
 	    PTR_ERR((void *)map_addr) == -EEXIST)
-		pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
-			task_pid_nr(current), current->comm, (void *)addr);
+		pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the memory is mapped already\n",
+			task_pid_nr(current), current->comm, addr);

"%px" does not hash. For what reason you replace %px with %lx ?

Quoted 4 lines
fs/binfmt_elf.c +0 -0
 	return(map_addr);
 }
 
#2 lore raw
Quoted 11 lines · Tetsuo Handa
Quoted 10 lines · Alexey Dobriyan

---

 fs/binfmt_elf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
fs/binfmt_elf.c +0 -0
@@ -379,8 +379,8 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 
Quoted 8 lines

fs/binfmt_elf.c static unsigned long elf_map(struct file *filep, unsigned long addr, · line 383

Quoted 6 lines
fs/binfmt_elf.c +2 -2
 	if ((type & MAP_FIXED_NOREPLACE) &&
 	    PTR_ERR((void *)map_addr) == -EEXIST)
-		pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
-			task_pid_nr(current), current->comm, (void *)addr);
+		pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the memory is mapped already\n",
+			task_pid_nr(current), current->comm, addr);

"%px" does not hash. For what reason you replace %px with %lx ?

Duh. There is no reason to use non-standard %px.

#3 lore raw
Quoted 21 lines · Alexey Dobriyan
Quoted 11 lines · Tetsuo Handa
Quoted 10 lines · Alexey Dobriyan

---

 fs/binfmt_elf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
fs/binfmt_elf.c +0 -0
@@ -379,8 +379,8 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 
Quoted 8 lines

fs/binfmt_elf.c static unsigned long elf_map(struct file *filep, unsigned long addr, · line 383

Quoted 6 lines
fs/binfmt_elf.c +2 -2
 	if ((type & MAP_FIXED_NOREPLACE) &&
 	    PTR_ERR((void *)map_addr) == -EEXIST)
-		pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
-			task_pid_nr(current), current->comm, (void *)addr);
+		pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the memory is mapped already\n",
+			task_pid_nr(current), current->comm, addr);

"%px" does not hash. For what reason you replace %px with %lx ?

Quoted 2 lines

Duh. There is no reason to use non-standard %px.

See the comment for pointer() function in lib/vsprintf.c . In Linux kernel world, various extension for %p is supported.

#4 lore raw
Quoted 22 lines · Tetsuo Handa
Quoted 21 lines · Alexey Dobriyan
Quoted 19 lines · Tetsuo Handa
Quoted 9 lines · Alexey Dobriyan

---

 fs/binfmt_elf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

fs/binfmt_elf.c static unsigned long elf_map(struct file *filep, unsigned long addr, · line 383

Quoted 7 lines
fs/binfmt_elf.c +2 -2
@@ -379,8 +379,8 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
 
 	if ((type & MAP_FIXED_NOREPLACE) &&
 	    PTR_ERR((void *)map_addr) == -EEXIST)
-		pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
-			task_pid_nr(current), current->comm, (void *)addr);
+		pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the memory is mapped already\n",
+			task_pid_nr(current), current->comm, addr);

"%px" does not hash. For what reason you replace %px with %lx ?

Quoted 5 lines
Quoted 2 lines

Duh. There is no reason to use non-standard %px.

See the comment for pointer() function in lib/vsprintf.c . In Linux kernel world, various extension for %p is supported.

%p has this funny property: scanf(printf("%p", ptr)) does not equal %p because small pointer will become (null) or (errptr) or whatever is decided in recent vsnprintf thread, therefore the less %p is used the better.