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authorMax Filippov <jcmvbkbc@gmail.com>2018-11-26 18:06:01 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-05 19:41:23 +0100
commitd36e4ee3b3ce4cf93e8fa145841287bbdb140fec (patch)
tree3cc438a14e92ab57fdcaac0153083f4115fb44c9
parentb35182226166c03713a10ffebcf2838569c95d57 (diff)
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xtensa: fix coprocessor part of ptrace_{get,set}xregs
commit 38a35a78c5e270cbe53c4fef6b0d3c2da90dd849 upstream. Layout of coprocessor registers in the elf_xtregs_t and xtregs_coprocessor_t may be different due to alignment. Thus it is not always possible to copy data between the xtregs_coprocessor_t structure and the elf_xtregs_t and get correct values for all registers. Use a table of offsets and sizes of individual coprocessor register groups to do coprocessor context copying in the ptrace_getxregs and ptrace_setxregs. This fixes incorrect coprocessor register values reading from the user process by the native gdb on an xtensa core with multiple coprocessors and registers with high alignment requirements. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/xtensa/kernel/ptrace.c42
1 files changed, 38 insertions, 4 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index e2461968efb2..7c3ed7d78075 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -127,12 +127,37 @@ static int ptrace_setregs(struct task_struct *child, void __user *uregs)
}
+#if XTENSA_HAVE_COPROCESSORS
+#define CP_OFFSETS(cp) \
+ { \
+ .elf_xtregs_offset = offsetof(elf_xtregs_t, cp), \
+ .ti_offset = offsetof(struct thread_info, xtregs_cp.cp), \
+ .sz = sizeof(xtregs_ ## cp ## _t), \
+ }
+
+static const struct {
+ size_t elf_xtregs_offset;
+ size_t ti_offset;
+ size_t sz;
+} cp_offsets[] = {
+ CP_OFFSETS(cp0),
+ CP_OFFSETS(cp1),
+ CP_OFFSETS(cp2),
+ CP_OFFSETS(cp3),
+ CP_OFFSETS(cp4),
+ CP_OFFSETS(cp5),
+ CP_OFFSETS(cp6),
+ CP_OFFSETS(cp7),
+};
+#endif
+
static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
{
struct pt_regs *regs = task_pt_regs(child);
struct thread_info *ti = task_thread_info(child);
elf_xtregs_t __user *xtregs = uregs;
int ret = 0;
+ int i __maybe_unused;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
return -EIO;
@@ -140,8 +165,13 @@ static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessor registers to memory. */
coprocessor_flush_all(ti);
- ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
- sizeof(xtregs_coprocessor_t));
+
+ for (i = 0; i < ARRAY_SIZE(cp_offsets); ++i)
+ ret |= __copy_to_user((char __user *)xtregs +
+ cp_offsets[i].elf_xtregs_offset,
+ (const char *)ti +
+ cp_offsets[i].ti_offset,
+ cp_offsets[i].sz);
#endif
ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
sizeof(xtregs->opt));
@@ -157,6 +187,7 @@ static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
struct pt_regs *regs = task_pt_regs(child);
elf_xtregs_t *xtregs = uregs;
int ret = 0;
+ int i __maybe_unused;
if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
return -EFAULT;
@@ -166,8 +197,11 @@ static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
coprocessor_flush_all(ti);
coprocessor_release_all(ti);
- ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0,
- sizeof(xtregs_coprocessor_t));
+ for (i = 0; i < ARRAY_SIZE(cp_offsets); ++i)
+ ret |= __copy_from_user((char *)ti + cp_offsets[i].ti_offset,
+ (const char __user *)xtregs +
+ cp_offsets[i].elf_xtregs_offset,
+ cp_offsets[i].sz);
#endif
ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
sizeof(xtregs->opt));