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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 15:15:09 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-07 19:45:24 +0200 |
| commit | 172b75e56b08846e6fb07a88e5685ce4e24f4620 (patch) | |
| tree | 93def6ef8018f5ad625cb03347893a7c3fddb667 /arch/x86/kernel/umip.c | |
| parent | 05a2ae7c033ee30f25fbed3ceed549a5cac398a9 (diff) | |
| download | linux-172b75e56b08846e6fb07a88e5685ce4e24f4620.tar.gz linux-172b75e56b08846e6fb07a88e5685ce4e24f4620.tar.bz2 linux-172b75e56b08846e6fb07a88e5685ce4e24f4620.zip | |
x86/umip: Factor out instruction fetch
Factor out the code to fetch the instruction from user-space to a helper
function.
No functional changes.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-9-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/umip.c')
| -rw-r--r-- | arch/x86/kernel/umip.c | 26 |
1 files changed, 6 insertions, 20 deletions
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index 2c304fd0bb1a..ad135be4f1f0 100644 --- a/arch/x86/kernel/umip.c +++ b/arch/x86/kernel/umip.c @@ -335,11 +335,11 @@ static void force_sig_info_umip_fault(void __user *addr, struct pt_regs *regs) */ bool fixup_umip_exception(struct pt_regs *regs) { - int not_copied, nr_copied, reg_offset, dummy_data_size, umip_inst; - unsigned long seg_base = 0, *reg_addr; + int nr_copied, reg_offset, dummy_data_size, umip_inst; /* 10 bytes is the maximum size of the result of UMIP instructions */ unsigned char dummy_data[10] = { 0 }; unsigned char buf[MAX_INSN_SIZE]; + unsigned long *reg_addr; void __user *uaddr; struct insn insn; int seg_defs; @@ -347,26 +347,12 @@ bool fixup_umip_exception(struct pt_regs *regs) if (!regs) return false; - /* - * If not in user-space long mode, a custom code segment could be in - * use. This is true in protected mode (if the process defined a local - * descriptor table), or virtual-8086 mode. In most of the cases - * seg_base will be zero as in USER_CS. - */ - if (!user_64bit_mode(regs)) - seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS); - - if (seg_base == -1L) - return false; - - not_copied = copy_from_user(buf, (void __user *)(seg_base + regs->ip), - sizeof(buf)); - nr_copied = sizeof(buf) - not_copied; + nr_copied = insn_fetch_from_user(regs, buf); /* - * The copy_from_user above could have failed if user code is protected - * by a memory protection key. Give up on emulation in such a case. - * Should we issue a page fault? + * The insn_fetch_from_user above could have failed if user code + * is protected by a memory protection key. Give up on emulation + * in such a case. Should we issue a page fault? */ if (!nr_copied) return false; |