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| author | Vaibhav Jain <vaibhav@linux.vnet.ibm.com> | 2018-03-04 23:01:32 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-03-13 15:50:05 +1100 |
| commit | 1ff3b404019adf9d605224e1dce0677a0375d274 (patch) | |
| tree | e12830b3eafd08ffa3064b9bced36faed5f057c9 | |
| parent | e1368d0c9edbc366e45216e7295fd61ae55c2b12 (diff) | |
| download | linux-1ff3b404019adf9d605224e1dce0677a0375d274.tar.bz2 | |
powerpc/xmon: Clear all breakpoints when xmon is disabled via debugfs
Presently when xmon is disabled by debugfs any existing
instruction/data-access breakpoints set are not disabled. This may
lead to kernel oops when those breakpoints are hit as the necessary
debugger hooks aren't installed.
Hence this patch introduces a new function named clear_all_bpt() which
is called when xmon is disabled via debugfs. The function will
unpatch/clear all the trap and ciabr/dab based breakpoints.
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Fix build break when CONFIG_DEBUG_FS=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/xmon/xmon.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index ee4b6071007d..3ddf9dd9a55f 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3664,11 +3664,35 @@ device_initcall(setup_xmon_sysrq); #endif /* CONFIG_MAGIC_SYSRQ */ #ifdef CONFIG_DEBUG_FS +static void clear_all_bpt(void) +{ + int i; + + /* clear/unpatch all breakpoints */ + remove_bpts(); + remove_cpu_bpts(); + + /* Disable all breakpoints */ + for (i = 0; i < NBPTS; ++i) + bpts[i].enabled = 0; + + /* Clear any data or iabr breakpoints */ + if (iabr || dabr.enabled) { + iabr = NULL; + dabr.enabled = 0; + } + + printf("xmon: All breakpoints cleared\n"); +} + static int xmon_dbgfs_set(void *data, u64 val) { xmon_on = !!val; xmon_init(xmon_on); + /* make sure all breakpoints removed when disabling */ + if (!xmon_on) + clear_all_bpt(); return 0; } |