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| author | Tomas Vanek <vanekt@fbl.cz> | 2022-08-02 11:33:07 +0200 |
|---|---|---|
| committer | Tomas Vanek <vanekt@fbl.cz> | 2022-08-14 12:11:26 +0000 |
| commit | b6dad912b85d6bcd78c12a7a44065fb85dd8485a (patch) | |
| tree | e45b2db1268ac402ac53da4111da3885a687f94f /src/target | |
| parent | cae0c8b32b32202f3552860f12f6579e8ad8ce4a (diff) | |
| download | riscv-openocd-b6dad912b85d6bcd78c12a7a44065fb85dd8485a.zip riscv-openocd-b6dad912b85d6bcd78c12a7a44065fb85dd8485a.tar.gz riscv-openocd-b6dad912b85d6bcd78c12a7a44065fb85dd8485a.tar.bz2 | |
target/cortex_m: prevent segmentation fault in cortex_m_poll()
If a Cortex-M MCU become unresponsive during a debug session and
re-examination fails to find MEM-AP, debug_ap pointer is set to NULL.
Eventual call of cortex_m_poll() dereferences debug_ap.
Check debug_ap validity at the begin of cortex_m_poll().
Change-Id: I9519f48760c91a48a9e5e8c34634d247098cb14a
Fixes: 35a503b08d14 (arm_adi_v5: add ap refcount and add get/put around ap use)
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7108
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Diffstat (limited to 'src/target')
| -rw-r--r-- | src/target/cortex_m.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c index 1682f5d..9497aa0 100644 --- a/src/target/cortex_m.c +++ b/src/target/cortex_m.c @@ -868,6 +868,16 @@ static int cortex_m_poll(struct target *target) struct cortex_m_common *cortex_m = target_to_cm(target); struct armv7m_common *armv7m = &cortex_m->armv7m; + /* Check if debug_ap is available to prevent segmentation fault. + * If the re-examination after an error does not find a MEM-AP + * (e.g. the target stopped communicating), debug_ap pointer + * can suddenly become NULL. + */ + if (!armv7m->debug_ap) { + target->state = TARGET_UNKNOWN; + return ERROR_TARGET_NOT_EXAMINED; + } + /* Read from Debug Halting Control and Status Register */ retval = cortex_m_read_dhcsr_atomic_sticky(target); if (retval != ERROR_OK) { |