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A few MIPS fixes for 4.19:

Browse Source 
- Avoid suboptimal placement of our VDSO when using the legacy mmap
   layout, which can prevent statically linked programs that were able to
   allocate large amounts of memory using the brk syscall prior to the
   introduction of our VDSO from functioning correctly.
 
 - Fix up CONFIG_CMDLINE handling for platforms which ought to ignore DT
   arguments but have incorrectly used them & lost other arguments since
   v3.16.
 
 - Fix a path in MAINTAINERS to use valid wildcards.
 
 - Fixup a regression from v4.17 in memset() for systems using
   CPU_DADDI_WORKAROUNDS.
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Merge tag 'mips_fixes_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Paul writes:
  "A few MIPS fixes for 4.19:

   - Avoid suboptimal placement of our VDSO when using the legacy mmap
     layout, which can prevent statically linked programs that were able
     to allocate large amounts of memory using the brk syscall prior to
     the introduction of our VDSO from functioning correctly.

   - Fix up CONFIG_CMDLINE handling for platforms which ought to ignore
     DT arguments but have incorrectly used them & lost other arguments
     since v3.16.

   - Fix a path in MAINTAINERS to use valid wildcards.

   - Fixup a regression from v4.17 in memset() for systems using
     CPU_DADDI_WORKAROUNDS."

* tag 'mips_fixes_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: memset: Fix CPU_DADDI_WORKAROUNDS `small_fixup' regression
  MAINTAINERS: MIPS/LOONGSON2 ARCHITECTURE - Use the normal wildcard style
  MIPS: Fix CONFIG_CMDLINE handling
  MIPS: VDSO: Always map near top of user memory
This commit is contained in:
Greg Kroah-Hartman 2018-10-10 08:43:15 +02:00
commit 701f2eb6f9
6 changed files with 80 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
MAINTAINERS
View File

@ -9657,7 +9657,8 @@ MIPS/LOONGSON2 ARCHITECTURE
M: Jiaxun Yang <jiaxun.yang@flygoat.com>
L: linux-mips@linux-mips.org
S: Maintained
F: arch/mips/loongson64/*{2e/2f}*
F: arch/mips/loongson64/fuloong-2e/
F: arch/mips/loongson64/lemote-2f/
F: arch/mips/include/asm/mach-loongson64/
F: drivers/*/*loongson2*
F: drivers/*/*/*loongson2*

10
arch/mips/include/asm/processor.h
View File

@ -13,6 +13,7 @@
#include <linux/atomic.h>
#include <linux/cpumask.h>
#include <linux/sizes.h>
#include <linux/threads.h>
#include <asm/cachectl.h>
@ -80,11 +81,10 @@ extern unsigned int vced_count, vcei_count;
#endif
/*
* One page above the stack is used for branch delay slot "emulation".
* See dsemul.c for details.
*/
#define STACK_TOP ((TASK_SIZE & PAGE_MASK) - PAGE_SIZE)
#define VDSO_RANDOMIZE_SIZE (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_256M)
extern unsigned long mips_stack_top(void);
#define STACK_TOP mips_stack_top()
/*
* This decides where the kernel will search for a free chunk of vm

25
arch/mips/kernel/process.c
View File

@ -32,6 +32,7 @@
#include <linux/nmi.h>
#include <linux/cpu.h>
#include <asm/abi.h>
#include <asm/asm.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
@ -39,6 +40,7 @@
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/irq.h>
#include <asm/mips-cps.h>
#include <asm/msa.h>
#include <asm/pgtable.h>
#include <asm/mipsregs.h>
@ -645,6 +647,29 @@ out:
return pc;
}
unsigned long mips_stack_top(void)
{
unsigned long top = TASK_SIZE & PAGE_MASK;
/* One page for branch delay slot "emulation" */
top -= PAGE_SIZE;
/* Space for the VDSO, data page & GIC user page */
top -= PAGE_ALIGN(current->thread.abi->vdso->size);
top -= PAGE_SIZE;
top -= mips_gic_present() ? PAGE_SIZE : 0;
/* Space for cache colour alignment */
if (cpu_has_dc_aliases)
top -= shm_align_mask + 1;
/* Space to randomize the VDSO base */
if (current->flags & PF_RANDOMIZE)
top -= VDSO_RANDOMIZE_SIZE;
return top;
}
/*
* Don't forget that the stack pointer must be aligned on a 8 bytes
* boundary for 32-bits ABI and 16 bytes for 64-bits ABI.

48
arch/mips/kernel/setup.c
View File

@ -846,6 +846,34 @@ static void __init arch_mem_init(char **cmdline_p)
struct memblock_region *reg;
extern void plat_mem_setup(void);
/*
* Initialize boot_command_line to an innocuous but non-empty string in
* order to prevent early_init_dt_scan_chosen() from copying
* CONFIG_CMDLINE into it without our knowledge. We handle
* CONFIG_CMDLINE ourselves below & don't want to duplicate its
* content because repeating arguments can be problematic.
*/
strlcpy(boot_command_line, " ", COMMAND_LINE_SIZE);
/* call board setup routine */
plat_mem_setup();
/*
* 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();
#if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE)
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
@ -873,26 +901,6 @@ static void __init arch_mem_init(char **cmdline_p)
}
#endif
#endif
/* call board setup routine */
plat_mem_setup();
/*
* 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();
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;

18
arch/mips/kernel/vdso.c
View File

@ -15,6 +15,7 @@
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timekeeper_internal.h>
@ -97,6 +98,21 @@ void update_vsyscall_tz(void)
}
}
static unsigned long vdso_base(void)
{
unsigned long base;
/* Skip the delay slot emulation page */
base = STACK_TOP + PAGE_SIZE;
if (current->flags & PF_RANDOMIZE) {
base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1);
base = PAGE_ALIGN(base);
}
return base;
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mips_vdso_image *image = current->thread.abi->vdso;
@ -137,7 +153,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (cpu_has_dc_aliases)
size += shm_align_mask + 1;
base = get_unmapped_area(NULL, 0, size, 0, 0);
base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
if (IS_ERR_VALUE(base)) {
ret = base;
goto out;

4
arch/mips/lib/memset.S
View File

@ -280,9 +280,11 @@
* unset_bytes = end_addr - current_addr + 1
* a2 = t1 - a0 + 1
*/
.set reorder
PTR_SUBU a2, t1, a0
PTR_ADDIU a2, 1
jr ra
PTR_ADDIU a2, 1
.set noreorder
.endm