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Patch by Lucian Adrian Grijincu: Added support for loading kernel modules

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with only a single readable/writable/executable text+data segment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37415 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Ingo Weinhold 2010-07-06 21:47:08 +00:00
parent 2548c4c974
commit f75e014cb8
2 changed files with 24 additions and 4 deletions
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2
headers/private/system/elf32.h
View File

@ -367,7 +367,7 @@ Elf32_Phdr::IsReadWrite() const
inline bool
Elf32_Phdr::IsExecutable() const
{
return (p_flags & PF_PROTECTION_MASK) == (PF_READ | PF_EXECUTE);
return (p_flags & PF_EXECUTE) != 0;
}

26
src/system/kernel/elf.cpp
View File

@ -1965,6 +1965,8 @@ load_kernel_add_on(const char *path)
size_t reservedSize;
status_t status;
ssize_t length;
bool textSectionWritable = false;
int executableHeaderCount = 0;
TRACE(("elf_load_kspace: entry path '%s'\n", path));
@ -2066,6 +2068,9 @@ load_kernel_add_on(const char *path)
B_PAGE_SIZE);
if (end > reservedSize)
reservedSize = end;
if (programHeaders[i].IsExecutable())
executableHeaderCount++;
}
// Check whether the segments have an unreasonable amount of unused space
@ -2105,7 +2110,16 @@ load_kernel_add_on(const char *path)
}
// we're here, so it must be a PT_LOAD segment
if (programHeaders[i].IsReadWrite()) {
// Usually add-ons have two PT_LOAD headers: one for .data one or .text.
// x86 and PPC may differ in permission bits for .data's PT_LOAD header
// x86 is usually RW, PPC is RWE
// Some add-ons may have .text and .data concatenated in a single
// PT_LOAD RWE header and we must map that to .text.
if (programHeaders[i].IsReadWrite()
&& (!programHeaders[i].IsExecutable()
|| executableHeaderCount > 1)) {
// this is the writable segment
if (image->data_region.size != 0) {
// we've already created this segment
@ -2122,6 +2136,9 @@ load_kernel_add_on(const char *path)
}
region = &image->text_region;
// some programs may have .text and .data concatenated in a
// single PT_LOAD section which is readable/writable/executable
textSectionWritable = programHeaders[i].IsReadWrite();
snprintf(regionName, B_OS_NAME_LENGTH, "%s_text", fileName);
} else {
dprintf("%s: weird program header flags 0x%lx\n", fileName,
@ -2191,9 +2208,12 @@ load_kernel_add_on(const char *path)
goto error5;
// We needed to read in the contents of the "text" area, but
// now we can protect it read-only/execute
// now we can protect it read-only/execute, unless this is a
// special image with concatenated .text and .data, when it
// will also need write access.
set_area_protection(image->text_region.id,
B_KERNEL_READ_AREA | B_KERNEL_EXECUTE_AREA);
B_KERNEL_READ_AREA | B_KERNEL_EXECUTE_AREA
| (textSectionWritable ? B_KERNEL_WRITE_AREA : 0));
// There might be a hole between the two segments, and we don't need to
// reserve this any longer