[POWERPC] Fix vDSO page count calculation

The recent vDSO consolidation patches broke powerpc due to a mistake in the definition of MAXPAGES constants. This fixes it by moving to a dynamically allocated array of pages instead as I don't like much hard coded size limits. Also move the vdso initialisation to an initcall since it doesn't really need to be done -that- early. Applogies for not catching the breakage earlier, Roland _did_ CC me on his patches a while ago, I got busy with other things and forgot to test them. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Fix vDSO page count calculation
The recent vDSO consolidation patches broke powerpc due to a mistake in the definition of MAXPAGES constants. This fixes it by moving to a dynamically allocated array of pages instead as I don't like much hard coded size limits. Also move the vdso initialisation to an initcall since it doesn't really need to be done -that- early. Applogies for not catching the breakage earlier, Roland _did_ CC me on his patches a while ago, I got busy with other things and forgot to test them. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Benjamin Herrenschmidt · Paul Mackerras
1 parent a334bdbdda
Showing 3 changed files with 23 additions and 19 deletions Side-by-side Diff
arch/powerpc/kernel/vdso.c
arch/powerpc/mm/mem.c
include/asm-powerpc/vdso.h
@@ -49,24 +49,23 @@
 /* Max supported size for symbol names */
 #define MAX_SYMNAME	64
  
-#define VDSO32_MAXPAGES	(((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
-#define VDSO64_MAXPAGES	(((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
-
 extern char vdso32_start, vdso32_end;
 static void *vdso32_kbase = &vdso32_start;
-unsigned int vdso32_pages;
-static struct page *vdso32_pagelist[VDSO32_MAXPAGES];
+static unsigned int vdso32_pages;
+static struct page **vdso32_pagelist;
 unsigned long vdso32_sigtramp;
 unsigned long vdso32_rt_sigtramp;
  
 #ifdef CONFIG_PPC64
 extern char vdso64_start, vdso64_end;
 static void *vdso64_kbase = &vdso64_start;
-unsigned int vdso64_pages;
-static struct page *vdso64_pagelist[VDSO64_MAXPAGES];
+static unsigned int vdso64_pages;
+static struct page **vdso64_pagelist;
 unsigned long vdso64_rt_sigtramp;
 #endif /* CONFIG_PPC64 */
  
+static int vdso_ready;
+
 /*
  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  * Once the early boot kernel code no longer needs to muck around
@@ -182,6 +181,9 @@
 	unsigned long vdso_base;
 	int rc;
  
+	if (!vdso_ready)
+		return 0;
+
 #ifdef CONFIG_PPC64
 	if (test_thread_flag(TIF_32BIT)) {
 		vdso_pagelist = vdso32_pagelist;
@@ -661,7 +663,7 @@
 }
  
  
-void __init vdso_init(void)
+static int __init vdso_init(void)
 {
 	int i;
  
  
@@ -716,11 +718,13 @@
 #ifdef CONFIG_PPC64
 		vdso64_pages = 0;
 #endif
-		return;
+		return 0;
 	}
  
 	/* Make sure pages are in the correct state */
-	BUG_ON(vdso32_pages + 2 > VDSO32_MAXPAGES);
+	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
+				  GFP_KERNEL);
+	BUG_ON(vdso32_pagelist == NULL);
 	for (i = 0; i < vdso32_pages; i++) {
 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 		ClearPageReserved(pg);
@@ -731,7 +735,9 @@
 	vdso32_pagelist[i] = NULL;
  
 #ifdef CONFIG_PPC64
-	BUG_ON(vdso64_pages + 2 > VDSO64_MAXPAGES);
+	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
+				  GFP_KERNEL);
+	BUG_ON(vdso64_pagelist == NULL);
 	for (i = 0; i < vdso64_pages; i++) {
 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 		ClearPageReserved(pg);
  
@@ -743,7 +749,13 @@
 #endif /* CONFIG_PPC64 */
  
 	get_page(virt_to_page(vdso_data));
+
+	smp_wmb();
+	vdso_ready = 1;
+
+	return 0;
 }
+arch_initcall(vdso_init);
  
 int in_gate_area_no_task(unsigned long addr)
 {
@@ -384,9 +384,6 @@
 		initsize >> 10);
  
 	mem_init_done = 1;
-
-	/* Initialize the vDSO */
-	vdso_init();
 }
  
 /*
@@ -18,15 +18,10 @@
  
 #ifndef __ASSEMBLY__
  
-extern unsigned int vdso64_pages;
-extern unsigned int vdso32_pages;
-
 /* Offsets relative to thread->vdso_base */
 extern unsigned long vdso64_rt_sigtramp;
 extern unsigned long vdso32_sigtramp;
 extern unsigned long vdso32_rt_sigtramp;
-
-extern void vdso_init(void);
  
 #else /* __ASSEMBLY__ */
...	...	@@ -49,24 +49,23 @@
49	49	/* Max supported size for symbol names */
50	50	#define MAX_SYMNAME 64
51	51
52		-#define VDSO32_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
53		-#define VDSO64_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
54		-
55	52	extern char vdso32_start, vdso32_end;
56	53	static void *vdso32_kbase = &vdso32_start;
57		-unsigned int vdso32_pages;
58		-static struct page *vdso32_pagelist[VDSO32_MAXPAGES];
	54	+static unsigned int vdso32_pages;
	55	+static struct page **vdso32_pagelist;
59	56	unsigned long vdso32_sigtramp;
60	57	unsigned long vdso32_rt_sigtramp;
61	58
62	59	#ifdef CONFIG_PPC64
63	60	extern char vdso64_start, vdso64_end;
64	61	static void *vdso64_kbase = &vdso64_start;
65		-unsigned int vdso64_pages;
66		-static struct page *vdso64_pagelist[VDSO64_MAXPAGES];
	62	+static unsigned int vdso64_pages;
	63	+static struct page **vdso64_pagelist;
67	64	unsigned long vdso64_rt_sigtramp;
68	65	#endif /* CONFIG_PPC64 */
69	66
	67	+static int vdso_ready;
	68	+
70	69	/*
71	70	* The vdso data page (aka. systemcfg for old ppc64 fans) is here.
72	71	* Once the early boot kernel code no longer needs to muck around
...	...	@@ -182,6 +181,9 @@
182	181	unsigned long vdso_base;
183	182	int rc;
184	183
	184	+ if (!vdso_ready)
	185	+ return 0;
	186	+
185	187	#ifdef CONFIG_PPC64
186	188	if (test_thread_flag(TIF_32BIT)) {
187	189	vdso_pagelist = vdso32_pagelist;
...	...	@@ -661,7 +663,7 @@
661	663	}
662	664
663	665
664		-void __init vdso_init(void)
	666	+static int __init vdso_init(void)
665	667	{
666	668	int i;
667	669
668	670
...	...	@@ -716,11 +718,13 @@
716	718	#ifdef CONFIG_PPC64
717	719	vdso64_pages = 0;
718	720	#endif
719		- return;
	721	+ return 0;
720	722	}
721	723
722	724	/* Make sure pages are in the correct state */
723		- BUG_ON(vdso32_pages + 2 > VDSO32_MAXPAGES);
	725	+ vdso32_pagelist = kzalloc(sizeof(struct page ) (vdso32_pages + 2),
	726	+ GFP_KERNEL);
	727	+ BUG_ON(vdso32_pagelist == NULL);
724	728	for (i = 0; i < vdso32_pages; i++) {
725	729	struct page pg = virt_to_page(vdso32_kbase + iPAGE_SIZE);
726	730	ClearPageReserved(pg);
...	...	@@ -731,7 +735,9 @@
731	735	vdso32_pagelist[i] = NULL;
732	736
733	737	#ifdef CONFIG_PPC64
734		- BUG_ON(vdso64_pages + 2 > VDSO64_MAXPAGES);
	738	+ vdso64_pagelist = kzalloc(sizeof(struct page ) (vdso64_pages + 2),
	739	+ GFP_KERNEL);
	740	+ BUG_ON(vdso64_pagelist == NULL);
735	741	for (i = 0; i < vdso64_pages; i++) {
736	742	struct page pg = virt_to_page(vdso64_kbase + iPAGE_SIZE);
737	743	ClearPageReserved(pg);
738	744
...	...	@@ -743,7 +749,13 @@
743	749	#endif /* CONFIG_PPC64 */
744	750
745	751	get_page(virt_to_page(vdso_data));
	752	+
	753	+ smp_wmb();
	754	+ vdso_ready = 1;
	755	+
	756	+ return 0;
746	757	}
	758	+arch_initcall(vdso_init);
747	759
748	760	int in_gate_area_no_task(unsigned long addr)
749	761	{
...	...	@@ -384,9 +384,6 @@
384	384	initsize >> 10);
385	385
386	386	mem_init_done = 1;
387		-
388		- /* Initialize the vDSO */
389		- vdso_init();
390	387	}
391	388
392	389	/*
...	...	@@ -18,15 +18,10 @@
18	18
19	19	#ifndef __ASSEMBLY__
20	20
21		-extern unsigned int vdso64_pages;
22		-extern unsigned int vdso32_pages;
23		-
24	21	/* Offsets relative to thread->vdso_base */
25	22	extern unsigned long vdso64_rt_sigtramp;
26	23	extern unsigned long vdso32_sigtramp;
27	24	extern unsigned long vdso32_rt_sigtramp;
28		-
29		-extern void vdso_init(void);
30	25
31	26	#else /* __ASSEMBLY__ */
32	27