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authorPavel Emelyanov <xemul@openvz.org>2008-03-28 17:27:00 -0400
committerTony Luck <tony.luck@intel.com>2008-04-09 13:33:36 -0400
commit96ded9dadde397a9e372a650534a9ffbba97194a (patch)
tree9aaa92034e87218d3ab7ba7e33fad0661899a0ad /arch/ia64
parentd167cb85150bd473a27df71e3116a9cc0008f5dd (diff)
[IA64] fix getpid and set_tid_address fast system calls for pid namespaces
The sys_getpid() and sys_set_tid_address() behavior changed from return current->tgid to struct pid *pid; pid = current->pids[PIDTYPE_PID].pid; return pid->numbers[pid->level].nr; But the fast system calls on ia64 still operate the old way. Patch them appropriately to let ia64 work with pid namespaces. Besides, this is one more step in deprecating of pid and tgid on task_struct. The fsys_getppid() is to be patched as well, but its logic is much more complex now, so I will make it later. One thing I'm not 100% sure is the trick with the IA64_UPID_SHIFT. On order to access the pid->level's element of an array I have to perform the following calculations pid + sizeof(struct upid) * pid->level The problem is that ia64 can only multiply float point registers, while all the offsets I have in code are in rXX ones. Fortunately, the sizeof(struct upid) is 32 bytes on ia64 (and is very unlikely to ever change), so the calculations get simpler: pid + pid->level << 5 So, I introduce the IA64_UPID_SHIFT and use the shl instruction. I also looked at how gcc compiles the similar place and found that it makes it with shift as well. Is this OK to do so? Tested with ski emulator with 2.6.24 kernel, but fits 2.6.25-rc4 and 2.6.25-rc4-mm1 as well. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: David Mosberger-Tang <davidm@hpl.hp.com> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
-rw-r--r--arch/ia64/kernel/asm-offsets.c7
-rw-r--r--arch/ia64/kernel/fsys.S34
2 files changed, 37 insertions, 4 deletions
diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index 0aebc6f79e95..f7bc40dee43d 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -7,6 +7,7 @@
7#define ASM_OFFSETS_C 1 7#define ASM_OFFSETS_C 1
8 8
9#include <linux/sched.h> 9#include <linux/sched.h>
10#include <linux/pid.h>
10#include <linux/clocksource.h> 11#include <linux/clocksource.h>
11 12
12#include <asm-ia64/processor.h> 13#include <asm-ia64/processor.h>
@@ -34,6 +35,9 @@ void foo(void)
34 DEFINE(SIGFRAME_SIZE, sizeof (struct sigframe)); 35 DEFINE(SIGFRAME_SIZE, sizeof (struct sigframe));
35 DEFINE(UNW_FRAME_INFO_SIZE, sizeof (struct unw_frame_info)); 36 DEFINE(UNW_FRAME_INFO_SIZE, sizeof (struct unw_frame_info));
36 37
38 BUILD_BUG_ON(sizeof(struct upid) != 32);
39 DEFINE(IA64_UPID_SHIFT, 5);
40
37 BLANK(); 41 BLANK();
38 42
39 DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); 43 DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
@@ -45,6 +49,9 @@ void foo(void)
45 DEFINE(IA64_TASK_BLOCKED_OFFSET,offsetof (struct task_struct, blocked)); 49 DEFINE(IA64_TASK_BLOCKED_OFFSET,offsetof (struct task_struct, blocked));
46 DEFINE(IA64_TASK_CLEAR_CHILD_TID_OFFSET,offsetof (struct task_struct, clear_child_tid)); 50 DEFINE(IA64_TASK_CLEAR_CHILD_TID_OFFSET,offsetof (struct task_struct, clear_child_tid));
47 DEFINE(IA64_TASK_GROUP_LEADER_OFFSET, offsetof (struct task_struct, group_leader)); 51 DEFINE(IA64_TASK_GROUP_LEADER_OFFSET, offsetof (struct task_struct, group_leader));
52 DEFINE(IA64_TASK_TGIDLINK_OFFSET, offsetof (struct task_struct, pids[PIDTYPE_PID].pid));
53 DEFINE(IA64_PID_LEVEL_OFFSET, offsetof (struct pid, level));
54 DEFINE(IA64_PID_UPID_OFFSET, offsetof (struct pid, numbers[0]));
48 DEFINE(IA64_TASK_PENDING_OFFSET,offsetof (struct task_struct, pending)); 55 DEFINE(IA64_TASK_PENDING_OFFSET,offsetof (struct task_struct, pending));
49 DEFINE(IA64_TASK_PID_OFFSET, offsetof (struct task_struct, pid)); 56 DEFINE(IA64_TASK_PID_OFFSET, offsetof (struct task_struct, pid));
50 DEFINE(IA64_TASK_REAL_PARENT_OFFSET, offsetof (struct task_struct, real_parent)); 57 DEFINE(IA64_TASK_REAL_PARENT_OFFSET, offsetof (struct task_struct, real_parent));
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 44841971f077..3f570e6fcd9c 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -61,13 +61,29 @@ ENTRY(fsys_getpid)
61 .prologue 61 .prologue
62 .altrp b6 62 .altrp b6
63 .body 63 .body
64 add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
65 ;;
66 ld8 r17=[r17] // r17 = current->group_leader
64 add r9=TI_FLAGS+IA64_TASK_SIZE,r16 67 add r9=TI_FLAGS+IA64_TASK_SIZE,r16
65 ;; 68 ;;
66 ld4 r9=[r9] 69 ld4 r9=[r9]
67 add r8=IA64_TASK_TGID_OFFSET,r16 70 add r17=IA64_TASK_TGIDLINK_OFFSET,r17
68 ;; 71 ;;
69 and r9=TIF_ALLWORK_MASK,r9 72 and r9=TIF_ALLWORK_MASK,r9
70 ld4 r8=[r8] // r8 = current->tgid 73 ld8 r17=[r17] // r17 = current->group_leader->pids[PIDTYPE_PID].pid
74 ;;
75 add r8=IA64_PID_LEVEL_OFFSET,r17
76 ;;
77 ld4 r8=[r8] // r8 = pid->level
78 add r17=IA64_PID_UPID_OFFSET,r17 // r17 = &pid->numbers[0]
79 ;;
80 shl r8=r8,IA64_UPID_SHIFT
81 ;;
82 add r17=r17,r8 // r17 = &pid->numbers[pid->level]
83 ;;
84 ld4 r8=[r17] // r8 = pid->numbers[pid->level].nr
85 ;;
86 mov r17=0
71 ;; 87 ;;
72 cmp.ne p8,p0=0,r9 88 cmp.ne p8,p0=0,r9
73(p8) br.spnt.many fsys_fallback_syscall 89(p8) br.spnt.many fsys_fallback_syscall
@@ -126,15 +142,25 @@ ENTRY(fsys_set_tid_address)
126 .altrp b6 142 .altrp b6
127 .body 143 .body
128 add r9=TI_FLAGS+IA64_TASK_SIZE,r16 144 add r9=TI_FLAGS+IA64_TASK_SIZE,r16
145 add r17=IA64_TASK_TGIDLINK_OFFSET,r16
129 ;; 146 ;;
130 ld4 r9=[r9] 147 ld4 r9=[r9]
131 tnat.z p6,p7=r32 // check argument register for being NaT 148 tnat.z p6,p7=r32 // check argument register for being NaT
149 ld8 r17=[r17] // r17 = current->pids[PIDTYPE_PID].pid
132 ;; 150 ;;
133 and r9=TIF_ALLWORK_MASK,r9 151 and r9=TIF_ALLWORK_MASK,r9
134 add r8=IA64_TASK_PID_OFFSET,r16 152 add r8=IA64_PID_LEVEL_OFFSET,r17
135 add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16 153 add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
136 ;; 154 ;;
137 ld4 r8=[r8] 155 ld4 r8=[r8] // r8 = pid->level
156 add r17=IA64_PID_UPID_OFFSET,r17 // r17 = &pid->numbers[0]
157 ;;
158 shl r8=r8,IA64_UPID_SHIFT
159 ;;
160 add r17=r17,r8 // r17 = &pid->numbers[pid->level]
161 ;;
162 ld4 r8=[r17] // r8 = pid->numbers[pid->level].nr
163 ;;
138 cmp.ne p8,p0=0,r9 164 cmp.ne p8,p0=0,r9
139 mov r17=-1 165 mov r17=-1
140 ;; 166 ;;