The patch titled
uml: use correct register file size everywhere
has been added to the -mm tree. Its filename is
uml-use-correct-register-file-size-everywhere.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: uml: use correct register file size everywhere
From: Jeff Dike <jdike@xxxxxxxxxxx>
This patch uses MAX_REG_NR consistently to refer to the register file size.
FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the
ptrace register file size. MAX_REG_NR was introduced as a consistent way
to get the number of registers, but wasn't used everywhere it should be.
When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because
of a corrupted segment register value in the known-good register file. The
patch also adds a register dump at that point in case there are any future
problems here.
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/um/include/sysdep-x86_64/ptrace.h | 4 ----
arch/um/os-Linux/skas/mem.c | 10 +++++++---
arch/um/os-Linux/skas/process.c | 6 +++---
arch/um/os-Linux/sys-i386/registers.c | 5 +++--
arch/um/os-Linux/sys-x86_64/registers.c | 4 ++--
5 files changed, 15 insertions(+), 14 deletions(-)
diff -puN arch/um/include/sysdep-x86_64/ptrace.h~uml-use-correct-register-file-size-everywhere arch/um/include/sysdep-x86_64/ptrace.h
--- a/arch/um/include/sysdep-x86_64/ptrace.h~uml-use-correct-register-file-size-everywhere
+++ a/arch/um/include/sysdep-x86_64/ptrace.h
@@ -104,10 +104,6 @@ union uml_pt_regs {
#endif
#ifdef UML_CONFIG_MODE_SKAS
struct skas_regs {
- /* x86_64 ptrace uses sizeof(user_regs_struct) as its register
- * file size, while i386 uses FRAME_SIZE. Therefore, we need
- * to use UM_FRAME_SIZE here instead of HOST_FRAME_SIZE.
- */
unsigned long regs[MAX_REG_NR];
unsigned long fp[HOST_FP_SIZE];
struct faultinfo faultinfo;
diff -puN arch/um/os-Linux/skas/mem.c~uml-use-correct-register-file-size-everywhere arch/um/os-Linux/skas/mem.c
--- a/arch/um/os-Linux/skas/mem.c~uml-use-correct-register-file-size-everywhere
+++ a/arch/um/os-Linux/skas/mem.c
@@ -47,7 +47,7 @@ int multi_op_count = 0;
static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
{
unsigned long regs[MAX_REG_NR];
- int n;
+ int n, i;
long ret, offset;
unsigned long * data;
unsigned long * syscall;
@@ -65,9 +65,13 @@ static inline long do_syscall_stub(struc
(unsigned long) &__syscall_stub_start);
n = ptrace_setregs(pid, regs);
- if(n < 0)
+ if(n < 0){
+ printk("Registers - \n");
+ for(i = 0; i < MAX_REG_NR; i++)
+ printk("\t%d\t0x%lx\n", i, regs[i]);
panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
- n);
+ -n);
+ }
wait_stub_done(pid, 0, "do_syscall_stub");
diff -puN arch/um/os-Linux/skas/process.c~uml-use-correct-register-file-size-everywhere arch/um/os-Linux/skas/process.c
--- a/arch/um/os-Linux/skas/process.c~uml-use-correct-register-file-size-everywhere
+++ a/arch/um/os-Linux/skas/process.c
@@ -66,7 +66,7 @@ void wait_stub_done(int pid, int sig, ch
if((n < 0) || !WIFSTOPPED(status) ||
(WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
- unsigned long regs[HOST_FRAME_SIZE];
+ unsigned long regs[MAX_REG_NR];
if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
printk("Failed to get registers from stub, "
@@ -75,7 +75,7 @@ void wait_stub_done(int pid, int sig, ch
int i;
printk("Stub registers -\n");
- for(i = 0; i < HOST_FRAME_SIZE; i++)
+ for(i = 0; i < ARRAY_SIZE(regs); i++)
printk("\t%d - %lx\n", i, regs[i]);
}
panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
@@ -327,7 +327,7 @@ void userspace(union uml_pt_regs *regs)
int copy_context_skas0(unsigned long new_stack, int pid)
{
int err;
- unsigned long regs[HOST_FRAME_SIZE];
+ unsigned long regs[MAX_REG_NR];
unsigned long fp_regs[HOST_FP_SIZE];
unsigned long current_stack = current_stub_stack();
struct stub_data *data = (struct stub_data *) current_stack;
diff -puN arch/um/os-Linux/sys-i386/registers.c~uml-use-correct-register-file-size-everywhere arch/um/os-Linux/sys-i386/registers.c
--- a/arch/um/os-Linux/sys-i386/registers.c~uml-use-correct-register-file-size-everywhere
+++ a/arch/um/os-Linux/sys-i386/registers.c
@@ -15,7 +15,7 @@
/* These are set once at boot time and not changed thereafter */
-static unsigned long exec_regs[HOST_FRAME_SIZE];
+static unsigned long exec_regs[MAX_REG_NR];
static unsigned long exec_fp_regs[HOST_FP_SIZE];
static unsigned long exec_fpx_regs[HOST_XFP_SIZE];
static int have_fpx_regs = 1;
@@ -101,6 +101,7 @@ void init_registers(int pid)
{
int err;
+ memset(exec_regs, 0, sizeof(exec_regs));
err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
if(err)
panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
@@ -124,7 +125,7 @@ void init_registers(int pid)
void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
{
- memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
+ memcpy(regs, exec_regs, sizeof(exec_regs));
if(fp_regs != NULL)
memcpy(fp_regs, exec_fp_regs,
HOST_FP_SIZE * sizeof(unsigned long));
diff -puN arch/um/os-Linux/sys-x86_64/registers.c~uml-use-correct-register-file-size-everywhere arch/um/os-Linux/sys-x86_64/registers.c
--- a/arch/um/os-Linux/sys-x86_64/registers.c~uml-use-correct-register-file-size-everywhere
+++ a/arch/um/os-Linux/sys-x86_64/registers.c
@@ -14,7 +14,7 @@
/* These are set once at boot time and not changed thereafter */
-static unsigned long exec_regs[HOST_FRAME_SIZE];
+static unsigned long exec_regs[MAX_REG_NR];
static unsigned long exec_fp_regs[HOST_FP_SIZE];
void init_thread_registers(union uml_pt_regs *to)
@@ -72,7 +72,7 @@ void init_registers(int pid)
void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
{
- memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
+ memcpy(regs, exec_regs, sizeof(exec_regs));
if(fp_regs != NULL)
memcpy(fp_regs, exec_fp_regs,
HOST_FP_SIZE * sizeof(unsigned long));
_
Patches currently in -mm which might be from jdike@xxxxxxxxxxx are
uml-fix-epoll.patch
uml-fix-static-linking.patch
uml-use-correct-register-file-size-everywhere.patch
remove-hardcoding-of-hard_smp_processor_id-on-up.patch
uml-delete-unused-code.patch
uml-formatting-fixes.patch
uml-host_info-tidying.patch
uml-mark-tt-mode-code-for-future-removal.patch
uml-print-coredump-limits.patch
uml-handle-block-device-hotplug-errors.patch
uml-driver-formatting-fixes.patch
uml-driver-formatting-fixes-fix.patch
uml-network-interface-hotplug-error-handling.patch
array_size-check-for-type-uml-fix.patch
uml-fix-prototypes.patch
uml-move-sigio-testing-to-sigioc.patch
uml-create-archh.patch
uml-create-as-layouth.patch
uml-move-remaining-useful-contents-of-user_utilh.patch
uml-remove-user_utilh.patch
uml-add-missing-__init-declarations.patch
remove-unused-header-file-arch-um-kernel-tt-include-mode_kern-tth.patch
-
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