[PATCH] Correct printk %pF to work on all architectures
From: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: 2008-09-03 20:24:57
Also in:
linux-arch
Subsystem:
library code, linux for powerpc (32-bit and 64-bit), parisc architecture, the rest, vsprintf · Maintainers:
Andrew Morton, Madhavan Srinivasan, Michael Ellerman, "James E.J. Bottomley", Helge Deller, Linus Torvalds, Petr Mladek, Steven Rostedt
It was introduced by
commit 0fe1ef24f7bd0020f29ffe287dfdb9ead33ca0b2
Author: Linus Torvalds [off-list ref]
Date: Sun Jul 6 16:43:12 2008 -0700
vsprintf: add support for '%pS' and '%pF' pointer formats
However, the current way its coded doesn't work on parisc64. For two
reasons: 1) parisc isn't in the #ifdef and 2) parisc has a different
format for function descriptors
Make dereference_function_descriptor() more accommodating by allowing
architecture overrides. I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
arch/ia64/kernel/module.c | 9 +++++++++
arch/parisc/kernel/module.c | 13 +++++++++++++
arch/powerpc/kernel/module_64.c | 9 +++++++++
include/linux/kernel.h | 3 +++
lib/vsprintf.c | 12 ++++++------
5 files changed, 40 insertions(+), 6 deletions(-)
diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index 29aad34..596a862 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c@@ -31,6 +31,7 @@ #include <linux/elf.h> #include <linux/moduleloader.h> #include <linux/string.h> +#include <linux/uaccess.h> #include <linux/vmalloc.h> #include <asm/patch.h>
@@ -941,3 +942,11 @@ module_arch_cleanup (struct module *mod) if (mod->arch.core_unw_table) unw_remove_unwind_table(mod->arch.core_unw_table); } + +void *dereference_function_descriptor(void *ptr) +{ + void *p = NULL; + if (!probe_kernel_address(ptr, p)) + ptr = p; + return p; +}
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index fdacdd4..4ad80a5 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c@@ -47,6 +47,7 @@ #include <linux/string.h> #include <linux/kernel.h> #include <linux/bug.h> +#include <linux/uaccess.h> #include <asm/unwind.h>
@@ -860,3 +861,15 @@ void module_arch_cleanup(struct module *mod) deregister_unwind_table(mod); module_bug_cleanup(mod); } + +#ifdef CONFIG_64BIT +void *dereference_function_descriptor(void *ptr) +{ + Elf64_Fdesc *desc = ptr; + void *p = NULL; + + if (!probe_kernel_address(&desc->addr, p)) + ptr = p; + return p; +} +#endif
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index ee6a298..60e9749 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c@@ -21,6 +21,7 @@ #include <linux/err.h> #include <linux/vmalloc.h> #include <linux/bug.h> +#include <linux/uaccess.h> #include <asm/module.h> #include <asm/uaccess.h> #include <asm/firmware.h>
@@ -451,3 +452,11 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, return 0; } + +void *dereference_function_descriptor(void *ptr) +{ + void *p = NULL; + if (!probe_kernel_address(ptr, p)) + ptr = p; + return p; +}
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2651f80..8ff19b3 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h@@ -189,6 +189,9 @@ extern int __kernel_text_address(unsigned long addr); extern int kernel_text_address(unsigned long addr); struct pid; extern struct pid *session_of_pgrp(struct pid *pgrp); +/* function descriptor handling (if any) */ +extern void *dereference_function_descriptor(void *ptr); + #ifdef CONFIG_PRINTK asmlinkage int vprintk(const char *fmt, va_list args)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d8d1d11..cffcd95 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c@@ -513,13 +513,13 @@ static char *string(char *buf, char *end, char *s, int field_width, int precisio return buf; } -static inline void *dereference_function_descriptor(void *ptr) +/* + * Some architectures need special handling for pointers + * to functions, which are done via function descriptors + * Do a non weak override of this function for them + */ +void __weak *dereference_function_descriptor(void *ptr) { -#if defined(CONFIG_IA64) || defined(CONFIG_PPC64) - void *p; - if (!probe_kernel_address(ptr, p)) - ptr = p; -#endif return ptr; }
--
1.5.6.5