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| author | Dave Martin <Dave.Martin@arm.com> | 2017-01-18 19:25:24 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-01-18 21:05:12 +0300 |
| commit | ad9e202aa1ce571b1d7fed969d06f66067f8a086 (patch) | |
| tree | 75379a242a506cf3d3195946e9c2c1b755708979 /arch/arm64 | |
| parent | aeb1f39d814b2e21e5e5706a48834bfd553d0059 (diff) | |
| download | linux-ad9e202aa1ce571b1d7fed969d06f66067f8a086.tar.xz | |
arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields
We cannot preserve partial fields for hardware breakpoints, because
the values written by userspace to the hardware breakpoint
registers can't subsequently be recovered intact from the hardware.
So, just reject attempts to write incomplete fields with -EINVAL.
Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2cdb23 ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 91c4719dfc00..a22161ccf447 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -551,6 +551,8 @@ static int hw_break_set(struct task_struct *target, /* (address, ctrl) registers */ limit = regset->n * regset->size; while (count && offset < limit) { + if (count < PTRACE_HBP_ADDR_SZ) + return -EINVAL; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr, offset, offset + PTRACE_HBP_ADDR_SZ); if (ret) @@ -560,6 +562,8 @@ static int hw_break_set(struct task_struct *target, return ret; offset += PTRACE_HBP_ADDR_SZ; + if (!count) + break; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, offset, offset + PTRACE_HBP_CTRL_SZ); if (ret) |