[PATCH v3 06/21] vmcore: round up buffer size of ELF headers by PAGE_SIZE

From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
To: vgoyal@redhat.com, ebiederm@xmission.com, cpw@sgi.com,
	kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com,
	heiko.carstens@de.ibm.com, akpm@linux-foundation.org
Cc: zhangyanfei@cn.fujitsu.com, kexec@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 06/21] vmcore: round up buffer size of ELF headers by PAGE_SIZE
Date: Sat, 16 Mar 2013 13:01:21 +0900	[thread overview]
Message-ID: <20130316040121.15064.35279.stgit@localhost6.localdomain6> (raw)
In-Reply-To: <20130316040003.15064.62308.stgit@localhost6.localdomain6>

To satisfy mmap() page-size boundary requirement, round up buffer size
of ELF headers by PAGE_SIZE. The resulting value becomes offset of ELF
note segments and it's assigned in unique PT_NOTE program header
entry.

Also, some part that assumes past ELF headers' size is replaced by
this new rounded-up value.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
---

 fs/proc/vmcore.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 17e2501..dd9769d 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -339,7 +339,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 	phdr.p_flags   = 0;
 	note_off = ehdr_ptr->e_phoff +
 			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
-	phdr.p_offset  = note_off;
+	phdr.p_offset  = roundup(note_off, PAGE_SIZE);
 	phdr.p_vaddr   = phdr.p_paddr = 0;
 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 	phdr.p_align   = 0;
@@ -352,6 +352,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
 	/* Modify e_phnum to reflect merged headers. */
 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 
+	*elfsz = roundup(*elfsz, PAGE_SIZE);
 out:
 	return 0;
 }
@@ -447,7 +448,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
 	phdr.p_flags   = 0;
 	note_off = ehdr_ptr->e_phoff +
 			(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
-	phdr.p_offset  = note_off;
+	phdr.p_offset  = roundup(note_off, PAGE_SIZE);
 	phdr.p_vaddr   = phdr.p_paddr = 0;
 	phdr.p_filesz  = phdr.p_memsz = phdr_sz;
 	phdr.p_align   = 0;
@@ -460,6 +461,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
 	/* Modify e_phnum to reflect merged headers. */
 	ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
 
+	*elfsz = roundup(*elfsz, PAGE_SIZE);
 out:
 	return 0;
 }
@@ -480,9 +482,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
 	phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */
 
 	/* First program header is PT_NOTE header. */
-	vmcore_off = ehdr_ptr->e_phoff +
-			(ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) +
-			phdr_ptr->p_memsz; /* Note sections */
+	vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz,
+						  PAGE_SIZE);
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 		if (phdr_ptr->p_type != PT_LOAD)
@@ -517,9 +518,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
 	phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */
 
 	/* First program header is PT_NOTE header. */
-	vmcore_off = ehdr_ptr->e_phoff +
-			(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
-			phdr_ptr->p_memsz; /* Note sections */
+	vmcore_off = phdr_ptr->p_offset + roundup(phdr_ptr->p_memsz,
+						 PAGE_SIZE);
 
 	for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
 		if (phdr_ptr->p_type != PT_LOAD)


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
