diff options
| -rw-r--r-- | arch/x86/mm/fault.c | 38 |
1 files changed, 23 insertions, 15 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index f5efbdba2b6d..2ff25ad33233 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -603,10 +603,13 @@ static void show_ldttss(const struct desc_ptr *gdt, const char *name, u16 index) name, index, addr, (desc.limit0 | (desc.limit1 << 16))); } -static void errstr(unsigned long ec, char *buf, unsigned long mask, - const char *txt) +/* + * This helper function transforms the #PF error_code bits into + * "[PROT] [USER]" type of descriptive, almost human-readable error strings: + */ +static void err_str_append(unsigned long error_code, char *buf, unsigned long mask, const char *txt) { - if (ec & mask) { + if (error_code & mask) { if (buf[0]) strcat(buf, " "); strcat(buf, txt); @@ -614,10 +617,9 @@ static void errstr(unsigned long ec, char *buf, unsigned long mask, } static void -show_fault_oops(struct pt_regs *regs, unsigned long error_code, - unsigned long address) +show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long address) { - char errtxt[64]; + char err_txt[64]; if (!oops_may_print()) return; @@ -646,15 +648,21 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, address < PAGE_SIZE ? "NULL pointer dereference" : "paging request", (void *)address); - errtxt[0] = 0; - errstr(error_code, errtxt, X86_PF_PROT, "PROT"); - errstr(error_code, errtxt, X86_PF_WRITE, "WRITE"); - errstr(error_code, errtxt, X86_PF_USER, "USER"); - errstr(error_code, errtxt, X86_PF_RSVD, "RSVD"); - errstr(error_code, errtxt, X86_PF_INSTR, "INSTR"); - errstr(error_code, errtxt, X86_PF_PK, "PK"); - pr_alert("HW error: %s\n", error_code ? errtxt : - "normal kernel read fault"); + err_txt[0] = 0; + + /* + * Note: length of these appended strings including the separation space and the + * zero delimiter must fit into err_txt[]. + */ + err_str_append(error_code, err_txt, X86_PF_PROT, "[PROT]" ); + err_str_append(error_code, err_txt, X86_PF_WRITE, "[WRITE]"); + err_str_append(error_code, err_txt, X86_PF_USER, "[USER]" ); + err_str_append(error_code, err_txt, X86_PF_RSVD, "[RSVD]" ); + err_str_append(error_code, err_txt, X86_PF_INSTR, "[INSTR]"); + err_str_append(error_code, err_txt, X86_PF_PK, "[PK]" ); + + pr_alert("#PF error: %s\n", error_code ? err_txt : "[normal kernel read fault]"); + if (!(error_code & X86_PF_USER) && user_mode(regs)) { struct desc_ptr idt, gdt; u16 ldtr, tr; |
