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[IA64] do not sync RBS when changing PT_AR_BSP or PT_CFM

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Syncing is no longer needed, because user RBS is already
up-to-date.  Actually, if a debugger modified the contents
of the original RBS prior to changing PT_AR_BSP, the
modifications would get overwritten.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Petr Tesarik 2008-02-11 22:42:00 +01:00 committed by Tony Luck
parent 972559a052
commit 08b23d74e0
1 changed files with 3 additions and 16 deletions
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19
arch/ia64/kernel/ptrace.c
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@ -1011,14 +1011,9 @@ access_uarea (struct task_struct *child, unsigned long addr,
* the kernel was entered.
*
* Furthermore, when changing the contents of
* PT_AR_BSP (or PT_CFM) we MUST copy any
* users-level stacked registers that are
* stored on the kernel stack back to
* user-space because otherwise, we might end
* up clobbering kernel stacked registers.
* Also, if this happens while the task is
* blocked in a system call, which convert the
* state such that the non-system-call exit
* PT_AR_BSP (or PT_CFM) while the task is
* blocked in a system call, convert the state
* so that the non-system-call exit
* path is used. This ensures that the proper
* state will be picked up when resuming
* execution. However, it *also* means that
@ -1035,10 +1030,6 @@ access_uarea (struct task_struct *child, unsigned long addr,
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (*data != urbs_end) {
if (ia64_sync_user_rbs(child, sw,
pt->ar_bspstore,
urbs_end) < 0)
return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,
@ -1058,10 +1049,6 @@ access_uarea (struct task_struct *child, unsigned long addr,
urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
if (write_access) {
if (((cfm ^ *data) & PFM_MASK) != 0) {
if (ia64_sync_user_rbs(child, sw,
pt->ar_bspstore,
urbs_end) < 0)
return -1;
if (in_syscall(pt))
convert_to_non_syscall(child,
pt,