From e77b7447f7b30d70961e5bee45400f70baeb16fc Mon Sep 17 00:00:00 2001 From: Paul Fertser Date: Sun, 31 Aug 2014 11:04:39 +0400 Subject: [PATCH] target/arm_dpm: prevent endless loop in arm_dpm_full_context() The code treats registers that are shadowed in FIQ mode in a special way: to read them out the target is first switches to USR mode. But since USR != ANY the current implementation later skips register read, and the loop becomes endless in case any !valid ARM_MODE_ANY is present at the moment arm_dpm_full_context() is called. This was reported in https://sourceforge.net/p/openocd/tickets/76/. The issue surfaced because 2efb1f14f611f2ff8a380b703f3e8bcb8a95d1ad added two ARM_MODE_ANY registers ("sp" and "lr") which were not normally read, so at the time a user was calling "arm reg" they were not valid. Fix this by changing the mode appropriately while keeping the "mode" variable state intact so it would later match register's mode. Compile-tested only. Change-Id: I01840e8fa20ec392220138a3f1497ac25deb080a Signed-off-by: Paul Fertser Reviewed-on: http://openocd.zylin.com/2278 Tested-by: jenkins Reviewed-by: Spencer Oliver --- src/target/arm_dpm.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c index b602b80e4a..b8f392cddf 100644 --- a/src/target/arm_dpm.c +++ b/src/target/arm_dpm.c @@ -648,14 +648,15 @@ static int arm_dpm_full_context(struct target *target) did_read = true; mode = r->mode; - /* For R8..R12 when we've entered debug - * state in FIQ mode... patch mode. + /* For regular (ARM_MODE_ANY) R8..R12 + * in case we've entered debug state + * in FIQ mode we need to patch mode. */ - if (mode == ARM_MODE_ANY) - mode = ARM_MODE_USR; + if (mode != ARM_MODE_ANY) + retval = dpm_modeswitch(dpm, mode); + else + retval = dpm_modeswitch(dpm, ARM_MODE_USR); - /* REVISIT error checks */ - retval = dpm_modeswitch(dpm, mode); if (retval != ERROR_OK) goto done; } -- 2.30.2