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lib: Correct printk %pF to work on all architectures
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It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef2.  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>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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James Bottomley authored and Linus Torvalds committed Sep 9, 2008
1 parent 7ae115b commit deac93d
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Showing 8 changed files with 56 additions and 11 deletions.
3 changes: 3 additions & 0 deletions arch/ia64/include/asm/sections.h
Original file line number Diff line number Diff line change
Expand Up @@ -21,5 +21,8 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b
extern char __start_unwind[], __end_unwind[];
extern char __start_ivt_text[], __end_ivt_text[];

#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);

#endif /* _ASM_IA64_SECTIONS_H */

12 changes: 12 additions & 0 deletions arch/ia64/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,9 +31,11 @@
#include <linux/elf.h>
#include <linux/moduleloader.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>

#include <asm/patch.h>
#include <asm/sections.h>
#include <asm/unaligned.h>

#define ARCH_MODULE_DEBUG 0
Expand Down Expand Up @@ -941,3 +943,13 @@ 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)
{
struct fdesc *desc = ptr;
void *p;

if (!probe_kernel_address(&desc->ip, p))
ptr = p;
return ptr;
}
14 changes: 14 additions & 0 deletions arch/parisc/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,9 @@
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/uaccess.h>

#include <asm/sections.h>
#include <asm/unwind.h>

#if 0
Expand Down Expand Up @@ -860,3 +862,15 @@ 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;

if (!probe_kernel_address(&desc->addr, p))
ptr = p;
return ptr;
}
#endif
3 changes: 3 additions & 0 deletions arch/powerpc/include/asm/sections.h
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,9 @@ static inline int in_kernel_text(unsigned long addr)
return 0;
}

#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);

#endif

#endif /* __KERNEL__ */
Expand Down
13 changes: 12 additions & 1 deletion arch/powerpc/kernel/module_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -21,8 +21,9 @@
#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/sections.h>
#include <asm/firmware.h>
#include <asm/code-patching.h>
#include <linux/sort.h>
Expand Down Expand Up @@ -451,3 +452,13 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,

return 0;
}

void *dereference_function_descriptor(void *ptr)
{
struct ppc64_opd_entry *desc = ptr;
void *p;

if (!probe_kernel_address(&desc->funcaddr, p))
ptr = p;
return ptr;
}
6 changes: 6 additions & 0 deletions include/asm-generic/sections.h
Original file line number Diff line number Diff line change
Expand Up @@ -14,4 +14,10 @@ extern char __kprobes_text_start[], __kprobes_text_end[];
extern char __initdata_begin[], __initdata_end[];
extern char __start_rodata[], __end_rodata[];

/* function descriptor handling (if any). Override
* in asm/sections.h */
#ifndef dereference_function_descriptor
#define dereference_function_descriptor(p) (p)
#endif

#endif /* _ASM_GENERIC_SECTIONS_H_ */
5 changes: 5 additions & 0 deletions include/asm-parisc/sections.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,4 +4,9 @@
/* nothing to see, move along */
#include <asm-generic/sections.h>

#ifdef CONFIG_64BIT
#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);
#endif

#endif
11 changes: 1 addition & 10 deletions lib/vsprintf.c
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@

#include <asm/page.h> /* for PAGE_SIZE */
#include <asm/div64.h>
#include <asm/sections.h> /* for dereference_function_descriptor() */

/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) ((x) | 0x20)
Expand Down Expand Up @@ -513,16 +514,6 @@ static char *string(char *buf, char *end, char *s, int field_width, int precisio
return buf;
}

static inline void *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;
}

static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
{
unsigned long value = (unsigned long) ptr;
Expand Down

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