Populates the program headers using memory maps linked list which was
populated in patch 5. The source, size and permissions of the maps are
found out and filled respectively.
Signed-off-by: Janani Venkataraman <jananive@xxxxxxxxxxxxxxxxxx>
---
src/coredump.c | 6 +++
src/coredump.h | 2 +
src/elf.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/elf32.c | 2 +
src/elf64.c | 1 +
5 files changed, 119 insertions(+)
diff --git a/src/coredump.c b/src/coredump.c
index 0fd6343e..5cccb7a 100644
--- a/src/coredump.c
+++ b/src/coredump.c
@@ -231,6 +231,12 @@ cleanup:
if (cp.notes)
free_notes(cp.notes);
+ if (cp.phdrs)
+ free(cp.phdrs);
+
+ if (cp.phdrs_count)
+ free(cp.shdrs);
+
errno = status;
return ret;
diff --git a/src/coredump.h b/src/coredump.h
index dce6292..a729f16 100644
--- a/src/coredump.h
+++ b/src/coredump.h
@@ -68,4 +68,6 @@ struct core_proc {
int elf_class; /* Elf class of the process */
void *elf_hdr; /* Stores the ELF_header */
struct mem_note *notes; /* Head of Notes */
+ void *shdrs; /* Extra Program Headers */
+ void *phdrs; /* Program Headers */
};
diff --git a/src/elf.c b/src/elf.c
index 62dc5a9..a5a1feb 100644
--- a/src/elf.c
+++ b/src/elf.c
@@ -39,6 +39,11 @@
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
+/* Default alignment for program headers */
+#ifndef ELF_EXEC_PAGESIZE
+#define ELF_EXEC_PAGESIZE PAGESIZE
+#endif
+
/* Appending the note to the list */
static void append_note(struct mem_note *new_note, struct core_proc *cp)
{
@@ -110,6 +115,26 @@ static int add_note(const char *name, int type, unsigned int data_sz, void *data
return 0;
}
+/*
+ * Reads first few bytes of the address specified and checks if it is
+ * an ELF by checking the magic number.
+ */
+static int get_elf_hdr_vaddr(int pid, Elf_Ehdr *elf, Elf_Addr addr)
+{
+ int ret;
+ struct iovec local, remote;
+
+ local.iov_base = elf;
+ local.iov_len = sizeof(Elf_Ehdr);
+ remote.iov_base = (void *)addr;
+ remote.iov_len = sizeof(Elf_Ehdr);
+ ret = process_vm_readv(pid, &local, 1, &remote, 1, 0);
+ if (ret == -1)
+ return -1;
+
+ return check_elf_hdr(elf->e_ident);
+}
+
/* Fetchs ELF header of the executable */
static int get_elf_hdr_exe_file(int pid, Elf_Ehdr *elf)
{
@@ -568,6 +593,84 @@ static int fetch_thread_notes(struct core_proc *cp)
return 0;
}
+/* Populate Program headers */
+static int get_phdrs(int pid, struct core_proc *cp)
+{
+ int n;
+ struct maps *map = cp->vmas;
+ Elf_Ehdr elf;
+ Elf_Phdr *cp_phdrs;
+ Elf_Shdr *cp_shdrs;
+ Elf_Ehdr *cp_elf;
+ cp_elf = (Elf_Ehdr *)cp->elf_hdr;
+
+ cp->phdrs = calloc(cp->phdrs_count, sizeof(Elf_Phdr));
+ if (!cp->phdrs) {
+ status = errno;
+ gencore_log("Could not allocate memory for Program headers.\n");
+ return -1;
+ }
+
+ cp_phdrs = (Elf_Phdr *)cp->phdrs;
+
+ cp_phdrs[0].p_type = PT_NOTE;
+ cp_phdrs[0].p_offset = 0;
+ cp_phdrs[0].p_vaddr = 0;
+ cp_phdrs[0].p_paddr = 0;
+ /* Will fill the size after filling notes */
+ cp_phdrs[0].p_filesz = 0;
+ cp_phdrs[0].p_memsz = 0;
+
+ n = 1;
+
+ while (map) {
+
+ /* Filling the Program Header Values */
+ cp_phdrs[n].p_type = PT_LOAD;
+ cp_phdrs[n].p_offset = 0;
+ cp_phdrs[n].p_vaddr = map->src;
+ cp_phdrs[n].p_paddr = 0;
+ cp_phdrs[n].p_flags = 0;
+ if (map->r == 'r')
+ cp_phdrs[n].p_flags |= PF_R;
+ if (map->w == 'w')
+ cp_phdrs[n].p_flags |= PF_W;
+ if (map->x == 'x')
+ cp_phdrs[n].p_flags |= PF_X;
+
+ cp_phdrs[n].p_memsz = map->dst - map->src;
+
+ if (!(cp_phdrs[n].p_flags & PF_R))
+ cp_phdrs[n].p_filesz = 0;
+ else if (map->inode &&
+ get_elf_hdr_vaddr(pid, &elf, cp_phdrs[n].p_vaddr) == 0)
+ cp_phdrs[n].p_filesz = ELF_EXEC_PAGESIZE;
+ else
+ cp_phdrs[n].p_filesz = cp_phdrs[n].p_memsz;
+
+ cp_phdrs[n].p_align = ELF_EXEC_PAGESIZE;
+
+ n++;
+ map = map->next;
+ }
+
+ if (cp->phdrs_count > PN_XNUM) {
+ cp->shdrs = malloc(sizeof(Elf_Shdr));
+ if (!cp->shdrs) {
+ status = errno;
+ gencore_log("Could not allocate memory for Extra Program headers.\n");
+ return -1;
+ }
+ cp_shdrs = (Elf_Shdr *)cp->shdrs;
+ cp_shdrs->sh_type = SHT_NULL;
+ cp_shdrs->sh_size = cp_elf->e_shnum;
+ cp_shdrs->sh_link = cp_elf->e_shstrndx;
+ cp_shdrs->sh_info = cp->phdrs_count;
+ }
+
+ return 0;
+}
+
int do_elf_coredump(int pid, struct core_proc *cp)
{
int ret, i;
@@ -597,5 +700,10 @@ int do_elf_coredump(int pid, struct core_proc *cp)
if (ret)
return -1;
+ /* Get Program headers */
+ ret = get_phdrs(pid, cp);
+ if (ret)
+ return -1;
+
return 0;
}
diff --git a/src/elf32.c b/src/elf32.c
index 8ec287b..daf9940 100644
--- a/src/elf32.c
+++ b/src/elf32.c
@@ -38,4 +38,6 @@
#define Elf_Long int
#define Elf_prstatus compat_elf_prstatus
+#define Elf_Addr Elf32_Addr
+
#include "elf.c"
diff --git a/src/elf64.c b/src/elf64.c
index 780e2d4..651f218 100644
--- a/src/elf64.c
+++ b/src/elf64.c
@@ -37,5 +37,6 @@
#define Elf_prpsinfo elf_prpsinfo
#define Elf_Long long
#define Elf_prstatus elf_prstatus
+#define Elf_Addr Elf64_Addr
#include "elf.c"
--
To unsubscribe from this list: send the line "unsubscribe util-linux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
