The following commit has been merged into the ras/core branch of tip: Commit-ID: a05d54c41ecfa1a322b229b4e5ce50c157284f74 Gitweb: https://git.kernel.org/tip/a05d54c41ecfa1a322b229b4e5ce50c157284f74 Author: Tony Luck <tony.luck@xxxxxxxxx> AuthorDate: Tue, 06 Oct 2020 14:09:06 -07:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Wed, 07 Oct 2020 11:08:59 +02:00 x86/mce: Provide method to find out the type of an exception handler Avoid a proliferation of ex_has_*_handler() functions by having just one function that returns the type of the handler (if any). Drop the __visible attribute for this function. It is not called from assembler so the attribute is not necessary. Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lkml.kernel.org/r/20201006210910.21062-3-tony.luck@xxxxxxxxx --- arch/x86/include/asm/extable.h | 9 ++++++++- arch/x86/kernel/cpu/mce/severity.c | 5 ++++- arch/x86/mm/extable.c | 12 ++++++++---- 3 files changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/extable.h b/arch/x86/include/asm/extable.h index d8c2198..1f0cbc5 100644 --- a/arch/x86/include/asm/extable.h +++ b/arch/x86/include/asm/extable.h @@ -29,10 +29,17 @@ struct pt_regs; (b)->handler = (tmp).handler - (delta); \ } while (0) +enum handler_type { + EX_HANDLER_NONE, + EX_HANDLER_FAULT, + EX_HANDLER_UACCESS, + EX_HANDLER_OTHER +}; + extern int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, unsigned long fault_addr); extern int fixup_bug(struct pt_regs *regs, int trapnr); -extern bool ex_has_fault_handler(unsigned long ip); +extern enum handler_type ex_get_fault_handler_type(unsigned long ip); extern void early_fixup_exception(struct pt_regs *regs, int trapnr); #endif diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c index 0b072dc..c6494e6 100644 --- a/arch/x86/kernel/cpu/mce/severity.c +++ b/arch/x86/kernel/cpu/mce/severity.c @@ -225,10 +225,13 @@ static struct severity { */ static int error_context(struct mce *m, struct pt_regs *regs) { + enum handler_type t; + if ((m->cs & 3) == 3) return IN_USER; - if (mc_recoverable(m->mcgstatus) && ex_has_fault_handler(m->ip)) { + t = ex_get_fault_handler_type(m->ip); + if (mc_recoverable(m->mcgstatus) && t == EX_HANDLER_FAULT) { m->kflags |= MCE_IN_KERNEL_RECOV; return IN_KERNEL_RECOV; } diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 1d6cb07..de43525 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -125,17 +125,21 @@ __visible bool ex_handler_clear_fs(const struct exception_table_entry *fixup, } EXPORT_SYMBOL(ex_handler_clear_fs); -__visible bool ex_has_fault_handler(unsigned long ip) +enum handler_type ex_get_fault_handler_type(unsigned long ip) { const struct exception_table_entry *e; ex_handler_t handler; e = search_exception_tables(ip); if (!e) - return false; + return EX_HANDLER_NONE; handler = ex_fixup_handler(e); - - return handler == ex_handler_fault; + if (handler == ex_handler_fault) + return EX_HANDLER_FAULT; + else if (handler == ex_handler_uaccess) + return EX_HANDLER_UACCESS; + else + return EX_HANDLER_OTHER; } int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,
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