Commit 08b23d74 authored by Petr Tesarik's avatar Petr Tesarik Committed by Tony Luck
Browse files

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



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: default avatarPetr Tesarik <ptesarik@suse.cz>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 972559a0

arch/ia64/kernel/ptrace.c

+3 −16
Original line number Diff line number Diff line
@@ -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,