[PATCH] Fix core files so they make sense to gdb...

It is silly to use non-static variable for writting zeroes to the file.

And more seriously, foffset in core dump file dump function was incremented
too much, so some parts of core dump were shifted by size of few phdrs and
notes down, so although gdb was able to load that file, it did not make lot
of sense - in my test case data pages were shifted down by about 900 bytes.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 5610061..79b05a1 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1220,7 +1220,7 @@ static int notesize(struct memelfnote *en)
 
 static int alignfile(struct file *file, loff_t *foffset)
 {
-       char buf[4] = { 0, };
+       static const char buf[4] = { 0, };
        DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
        return 1;
 }
@@ -1569,7 +1569,8 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
 
        DUMP_WRITE(elf, sizeof(*elf));
        offset += sizeof(*elf);                         /* Elf header */
-       offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
+       offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
+       foffset = offset;
 
        /* Write notes phdr entry */
        {
@@ -1586,8 +1587,6 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
                DUMP_WRITE(&phdr, sizeof(phdr));
        }
 
-       foffset = offset;
-
        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
 
        /* Write program headers for segments dump */
@@ -1612,7 +1611,6 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
                phdr.p_align = ELF_EXEC_PAGESIZE;
 
                DUMP_WRITE(&phdr, sizeof(phdr));
-               foffset += sizeof(phdr);
        }
 
 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS