From: Petr Tesarik Date: Mon, 11 Feb 2008 21:42:00 +0000 (+0100) Subject: [IA64] do not sync RBS when changing PT_AR_BSP or PT_CFM X-Git-Tag: v2.6.25-rc5~18^2~10 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08b23d74e07ac053fe4a5d6f4a48e8048fcfe52b;p=linux-2.6 [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: Petr Tesarik Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 9d2591423e..54b7ea5515 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -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,