From 15029285dc977a392e74eacb7625984b71d4f605 Mon Sep 17 00:00:00 2001 From: Jason Uhlenkott Date: Fri, 30 Dec 2005 02:27:01 -0800 Subject: [PATCH] [IA64] Handle debug traps in fsys mode We need to handle debug traps in fsys mode non-fatally. They can happen now that we have fsyscalls which contain probe instructions. Signed-off-by: Jason Uhlenkott Signed-off-by: Tony Luck --- arch/ia64/kernel/traps.c | 26 +++++++++++++++++++------- include/asm-ia64/thread_info.h | 4 +++- 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c index d3e0ecb56d62..55391901b013 100644 --- a/arch/ia64/kernel/traps.c +++ b/arch/ia64/kernel/traps.c @@ -530,12 +530,15 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa, if (fsys_mode(current, ®s)) { extern char __kernel_syscall_via_break[]; /* - * Got a trap in fsys-mode: Taken Branch Trap and Single Step trap - * need special handling; Debug trap is not supposed to happen. + * Got a trap in fsys-mode: Taken Branch Trap + * and Single Step trap need special handling; + * Debug trap is ignored (we disable it here + * and re-enable it in the lower-privilege trap). */ if (unlikely(vector == 29)) { - die("Got debug trap in fsys-mode---not supposed to happen!", - ®s, 0); + set_thread_flag(TIF_DB_DISABLED); + ia64_psr(®s)->db = 0; + ia64_psr(®s)->lp = 1; return; } /* re-do the system call via break 0x100000: */ @@ -589,10 +592,19 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa, case 34: if (isr & 0x2) { /* Lower-Privilege Transfer Trap */ + + /* If we disabled debug traps during an fsyscall, + * re-enable them here. + */ + if (test_thread_flag(TIF_DB_DISABLED)) { + clear_thread_flag(TIF_DB_DISABLED); + ia64_psr(®s)->db = 1; + } + /* - * Just clear PSR.lp and then return immediately: all the - * interesting work (e.g., signal delivery is done in the kernel - * exit path). + * Just clear PSR.lp and then return immediately: + * all the interesting work (e.g., signal delivery) + * is done in the kernel exit path. */ ia64_psr(®s)->lp = 0; return; diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h index 653bb7f9a753..1d6518fe1f02 100644 --- a/include/asm-ia64/thread_info.h +++ b/include/asm-ia64/thread_info.h @@ -93,6 +93,7 @@ struct thread_info { #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 #define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */ +#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) @@ -100,9 +101,10 @@ struct thread_info { #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) -#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED) +#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_MCA_INIT (1 << TIF_MCA_INIT) +#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED) /* "work to do on user-return" bits */ #define TIF_ALLWORK_MASK (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SIGDELAYED)