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| author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2020-09-02 06:29:42 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-09-15 14:13:20 +0200 |
| commit | 5b905d77987de065bdd3a2906816b5f143df087b (patch) | |
| tree | 0c35d7c18b1d8902425b792d1102835ca582af13 /.mailmap | |
| parent | powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c (diff) | |
| download | linux-5b905d77987de065bdd3a2906816b5f143df087b.tar.xz linux-5b905d77987de065bdd3a2906816b5f143df087b.zip | |
powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N
On powerpc, ptrace watchpoint works in one-shot mode. i.e. kernel
disables event every time it fires and user has to re-enable it.
Also, in case of ptrace watchpoint, kernel notifies ptrace user
before executing instruction.
With CONFIG_HAVE_HW_BREAKPOINT=N, kernel is missing to disable
ptrace event and thus it's causing infinite loop of exceptions.
This is especially harmful when user watches on a data which is
also read/written by kernel, eg syscall parameters. In such case,
infinite exceptions happens in kernel mode which causes soft-lockup.
Fixes: 9422de3e953d ("powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers")
Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-6-ravi.bangoria@linux.ibm.com
Diffstat (limited to '.mailmap')
0 files changed, 0 insertions, 0 deletions