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Message-Id: <1482113266-13207-10-git-send-email-fancer.lancer@gmail.com>
Date: Mon, 19 Dec 2016 05:07:34 +0300
From: Serge Semin <fancer.lancer@...il.com>
To: ralf@...ux-mips.org, paul.burton@...tec.com, rabinv@...s.com,
matt.redfearn@...tec.com, james.hogan@...tec.com,
alexander.sverdlin@...ia.com, robh+dt@...nel.org,
frowand.list@...il.com
Cc: Sergey.Semin@...latforms.ru, linux-mips@...ux-mips.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Serge Semin <fancer.lancer@...il.com>
Subject: [PATCH 09/21] MIPS memblock: Move kernel memory reservation to individual method
The whole kernel text/data/bss must be reserved to prevent sudden
kernel crashes, for instance, due to unexpected non-zero default static
variables initializations.
Signed-off-by: Serge Semin <fancer.lancer@...il.com>
---
arch/mips/kernel/setup.c | 117 +++++++++++++++--------------
1 file changed, 59 insertions(+), 58 deletions(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 9c1a60d..e746793 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -472,6 +472,62 @@ static void __init mips_reserve_initrd_mem(void) { }
#endif
/*
+ * Reserve kernel code and data within memblock allocator
+ */
+static void __init mips_reserve_kernel_mem(void)
+{
+ phys_addr_t start, size;
+
+ /*
+ * Add kernel _text, _data, _bss, __init*, upto __end sections to
+ * boot_mem_map and memblock. We must reserve all of them!
+ */
+ start = __pa_symbol(&_text);
+ size = __pa_symbol(&_end) - start;
+ add_memory_region(start, size, BOOT_MEM_RAM);
+ /*
+ * It needs to be reserved within memblock as well. It's ok if memory
+ * has already been reserved with previous method
+ */
+ memblock_reserve(start, size);
+
+ /* Reserve nosave region for hibernation */
+ start = __pa_symbol(&__nosave_begin);
+ size = __pa_symbol(&__nosave_end) - start;
+ add_memory_region(start, size, BOOT_MEM_RAM);
+ memblock_reserve(start, size);
+
+ /* Initialize some init_mm fieldis. We may not need this? */
+ init_mm.start_code = (unsigned long)&_text;
+ init_mm.end_code = (unsigned long)&_etext;
+ init_mm.end_data = (unsigned long)&_edata;
+ init_mm.brk = (unsigned long)&_end;
+
+ /*
+ * The kernel reserves all memory below its _end symbol as bootmem,
+ * but the kernel may now be at a much higher address. The memory
+ * between the original and new locations may be returned to the system.
+ */
+#ifdef CONFIG_RELOCATABLE
+ if (__pa_symbol(&_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) {
+ phys_addr_t offset;
+ extern void show_kernel_relocation(const char *level);
+
+ offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS);
+ memblock_free(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset);
+
+#if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO)
+ /*
+ * This information is necessary when debugging the kernel
+ * But is a security vulnerability otherwise!
+ */
+ show_kernel_relocation(KERN_INFO);
+#endif
+ }
+#endif
+}
+
+/*
* Reserve memory occupied by elfcorehdr
*/
static void __init mips_reserve_elfcorehdr(void)
@@ -590,6 +646,9 @@ static void __init bootmem_init(void)
unsigned long bootmap_size;
int i;
+ /* Reserve kernel code/data memory */
+ mips_reserve_kernel_mem();
+
/* Check and reserve memory occupied by initrd */
mips_reserve_initrd_mem();
@@ -766,29 +825,6 @@ static void __init bootmem_init(void)
* Reserve the bootmap memory.
*/
reserve_bootmem(PFN_PHYS(mapstart), bootmap_size, BOOTMEM_DEFAULT);
-
-#ifdef CONFIG_RELOCATABLE
- /*
- * The kernel reserves all memory below its _end symbol as bootmem,
- * but the kernel may now be at a much higher address. The memory
- * between the original and new locations may be returned to the system.
- */
- if (__pa_symbol(_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) {
- unsigned long offset;
- extern void show_kernel_relocation(const char *level);
-
- offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS);
- free_bootmem(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset);
-
-#if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO)
- /*
- * This information is necessary when debugging the kernel
- * But is a security vulnerability otherwise!
- */
- show_kernel_relocation(KERN_INFO);
-#endif
- }
-#endif
}
#endif /* CONFIG_SGI_IP27 */
@@ -816,25 +852,6 @@ static void __init bootmem_init(void)
* initialization hook for anything else was introduced.
*/
-static void __init arch_mem_addpart(phys_addr_t mem, phys_addr_t end, int type)
-{
- phys_addr_t size;
- int i;
-
- size = end - mem;
- if (!size)
- return;
-
- /* Make sure it is in the boot_mem_map */
- for (i = 0; i < boot_mem_map.nr_map; i++) {
- if (mem >= boot_mem_map.map[i].addr &&
- mem < (boot_mem_map.map[i].addr +
- boot_mem_map.map[i].size))
- return;
- }
- add_memory_region(mem, size, type);
-}
-
static void __init arch_mem_init(char **cmdline_p)
{
struct memblock_region *reg;
@@ -846,19 +863,6 @@ static void __init arch_mem_init(char **cmdline_p)
/* Parse passed parameters */
mips_parse_param(cmdline_p);
- /*
- * Make sure all kernel memory is in the maps. The "UP" and
- * "DOWN" are opposite for initdata since if it crosses over
- * into another memory section you don't want that to be
- * freed when the initdata is freed.
- */
- arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT,
- PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT,
- BOOT_MEM_RAM);
- arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,
- PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,
- BOOT_MEM_INIT_RAM);
-
pr_info("Determined physical RAM map:\n");
print_memory_map();
@@ -873,9 +877,6 @@ static void __init arch_mem_init(char **cmdline_p)
for_each_memblock(reserved, reg)
if (reg->size != 0)
reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
-
- reserve_bootmem_region(__pa_symbol(&__nosave_begin),
- __pa_symbol(&__nosave_end)); /* Reserve for hibernation */
}
static void __init resource_init(void)
--
2.6.6
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