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arm64: mm: drop VM_FAULT_BADMAP/VM_FAULT_BADACCESS

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Patch series "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS", v2.

Directly set SEGV_MAPRR or SEGV_ACCERR for arm/arm64 to remove the last
two arch's private vm_fault reasons.  


This patch (of 2):

If bad map or access, directly set si_code to SEGV_MAPRR or SEGV_ACCERR,
also set fault to 0 and goto error handling, which make us to drop the
arch's special vm fault reason.

Link: https://lkml.kernel.org/r/20240411130925.73281-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240411130925.73281-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kefeng Wang 2024-04-11 21:09:24 +08:00 committed by Andrew Morton
parent 658670607f
commit eebb5181a0
1 changed files with 20 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
arch/arm64/mm/fault.c
View File

@ -500,9 +500,6 @@ static bool is_write_abort(unsigned long esr)
return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
}
#define VM_FAULT_BADMAP ((__force vm_fault_t)0x010000)
#define VM_FAULT_BADACCESS ((__force vm_fault_t)0x020000)
static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
struct pt_regs *regs)
{
@ -513,6 +510,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
unsigned int mm_flags = FAULT_FLAG_DEFAULT;
unsigned long addr = untagged_addr(far);
struct vm_area_struct *vma;
int si_code;
if (kprobe_page_fault(regs, esr))
return 0;
@ -572,9 +570,10 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
if (!(vma->vm_flags & vm_flags)) {
vma_end_read(vma);
fault = VM_FAULT_BADACCESS;
fault = 0;
si_code = SEGV_ACCERR;
count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
goto done;
goto bad_area;
}
fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs);
if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
@ -599,15 +598,19 @@ lock_mmap:
retry:
vma = lock_mm_and_find_vma(mm, addr, regs);
if (unlikely(!vma)) {
fault = VM_FAULT_BADMAP;
goto done;
fault = 0;
si_code = SEGV_MAPERR;
goto bad_area;
}
if (!(vma->vm_flags & vm_flags))
fault = VM_FAULT_BADACCESS;
else
fault = handle_mm_fault(vma, addr, mm_flags, regs);
if (!(vma->vm_flags & vm_flags)) {
mmap_read_unlock(mm);
fault = 0;
si_code = SEGV_ACCERR;
goto bad_area;
}
fault = handle_mm_fault(vma, addr, mm_flags, regs);
/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
if (!user_mode(regs))
@ -626,13 +629,12 @@ retry:
mmap_read_unlock(mm);
done:
/*
* Handle the "normal" (no error) case first.
*/
if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
VM_FAULT_BADACCESS))))
/* Handle the "normal" (no error) case first. */
if (likely(!(fault & VM_FAULT_ERROR)))
return 0;
si_code = SEGV_MAPERR;
bad_area:
/*
* If we are in kernel mode at this point, we have no context to
* handle this fault with.
@ -667,13 +669,8 @@ done:
arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
* map.
*/
arm64_force_sig_fault(SIGSEGV,
fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
far, inf->name);
/* Something tried to access memory that out of memory map */
arm64_force_sig_fault(SIGSEGV, si_code, far, inf->name);
}
return 0;