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| author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2006-10-02 13:17:30 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-02 18:57:16 +0400 |
| commit | 3a872d89baae821a0f6e2c1055d4b47650661137 (patch) | |
| tree | 5ac6aa55e04960e02f25ff5079078f975957b1b3 /include/asm-powerpc | |
| parent | 782237a2418e2561a87c86a4832726931adce737 (diff) | |
| download | linux-3a872d89baae821a0f6e2c1055d4b47650661137.tar.xz | |
[PATCH] Kprobes: Make kprobe modules more portable
In an effort to make kprobe modules more portable, here is a patch that:
o Introduces the "symbol_name" field to struct kprobe.
The symbol->address resolution now happens in the kernel in an
architecture agnostic manner. 64-bit powerpc users no longer have
to specify the ".symbols"
o Introduces the "offset" field to struct kprobe to allow a user to
specify an offset into a symbol.
o The legacy mechanism of specifying the kprobe.addr is still supported.
However, if both the kprobe.addr and kprobe.symbol_name are specified,
probe registration fails with an -EINVAL.
o The symbol resolution code uses kallsyms_lookup_name(). So
CONFIG_KPROBES now depends on CONFIG_KALLSYMS
o Apparantly kprobe modules were the only legitimate out-of-tree user of
the kallsyms_lookup_name() EXPORT. Now that the symbol resolution
happens in-kernel, remove the EXPORT as suggested by Christoph Hellwig
o Modify tcp_probe.c that uses the kprobe interface so as to make it
work on multiple platforms (in its earlier form, the code wouldn't
work, say, on powerpc)
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-powerpc')
| -rw-r--r-- | include/asm-powerpc/kprobes.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/asm-powerpc/kprobes.h b/include/asm-powerpc/kprobes.h index 34e1f89a5fa0..1ef54be6abfa 100644 --- a/include/asm-powerpc/kprobes.h +++ b/include/asm-powerpc/kprobes.h @@ -44,6 +44,21 @@ typedef unsigned int kprobe_opcode_t; #define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000) #define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000) +/* + * 64bit powerpc uses function descriptors. + * Handle cases where: + * - User passes a <.symbol> + * - User passes a <symbol> + * - User passes a non-existant symbol, kallsyms_lookup_name + * returns 0. Don't deref the NULL pointer in that case + */ +#define kprobe_lookup_name(name, addr) \ +{ \ + addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); \ + if (!(name[0] == '.') && addr) \ + addr = *(kprobe_opcode_t **)addr; \ +} + #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry) #define is_trap(instr) (IS_TW(instr) || IS_TD(instr) || \ |