| Message ID | 20240913084433.1016256-3-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: Use pxdp_get() for accessing page table entries | expand |
On 9/13/24 01:44, Anshuman Khandual wrote: > This drops page table entry address output from all pxd_ERROR() definitions > which now matches with other architectures. This also prevents build issues > while transitioning into pxdp_get() based page table entry accesses. Could you be a _little_ more specific than "build issues"? Is it that you want to do: void pmd_clear_bad(pmd_t *pmd) { - pmd_ERROR(*pmd); + pmd_ERROR(pmdp_get(pmd)); pmd_clear(pmd); } But the pmd_ERROR() macro would expand that to: &pmdp_get(pmd) which is nonsense? Having the PTEs' kernel addresses _is_ handy, but I guess they're scrambled on most end users' systems now and anybody that's actively debugging can just use a kprobe or something to dump the pmd_clear_bad() argument directly.
On 9/13/24 22:51, Dave Hansen wrote: > On 9/13/24 01:44, Anshuman Khandual wrote: >> This drops page table entry address output from all pxd_ERROR() definitions >> which now matches with other architectures. This also prevents build issues >> while transitioning into pxdp_get() based page table entry accesses. > > Could you be a _little_ more specific than "build issues"? Is it that > you want to do: > > void pmd_clear_bad(pmd_t *pmd) > { > - pmd_ERROR(*pmd); > + pmd_ERROR(pmdp_get(pmd)); > pmd_clear(pmd); > } > > But the pmd_ERROR() macro would expand that to: > > &pmdp_get(pmd) > > which is nonsense? Yes, that's the one which fails the build with the following warning. error: lvalue required as unary '&' operand Will update the commit message with these details about the build problem. > > Having the PTEs' kernel addresses _is_ handy, but I guess they're > scrambled on most end users' systems now and anybody that's actively > debugging can just use a kprobe or something to dump the pmd_clear_bad() > argument directly. Right.
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index dabafba957ea..e1fa4dd87753 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -10,14 +10,14 @@ */ #define pte_ERROR(e) \ - pr_err("%s:%d: bad pte %p(%08lx%08lx)\n", \ - __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low) + pr_err("%s:%d: bad pte (%08lx%08lx)\n", \ + __FILE__, __LINE__, (e).pte_high, (e).pte_low) #define pmd_ERROR(e) \ - pr_err("%s:%d: bad pmd %p(%016Lx)\n", \ - __FILE__, __LINE__, &(e), pmd_val(e)) + pr_err("%s:%d: bad pmd (%016Lx)\n", \ + __FILE__, __LINE__, pmd_val(e)) #define pgd_ERROR(e) \ - pr_err("%s:%d: bad pgd %p(%016Lx)\n", \ - __FILE__, __LINE__, &(e), pgd_val(e)) + pr_err("%s:%d: bad pgd (%016Lx)\n", \ + __FILE__, __LINE__, pgd_val(e)) #define pxx_xchg64(_pxx, _ptr, _val) ({ \ _pxx##val_t *_p = (_pxx##val_t *)_ptr; \ diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index 3c4407271d08..4e462c825cab 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -32,24 +32,24 @@ extern void paging_init(void); static inline void sync_initial_page_table(void) { } #define pte_ERROR(e) \ - pr_err("%s:%d: bad pte %p(%016lx)\n", \ - __FILE__, __LINE__, &(e), pte_val(e)) + pr_err("%s:%d: bad pte (%016lx)\n", \ + __FILE__, __LINE__, pte_val(e)) #define pmd_ERROR(e) \ - pr_err("%s:%d: bad pmd %p(%016lx)\n", \ - __FILE__, __LINE__, &(e), pmd_val(e)) + pr_err("%s:%d: bad pmd (%016lx)\n", \ + __FILE__, __LINE__, pmd_val(e)) #define pud_ERROR(e) \ - pr_err("%s:%d: bad pud %p(%016lx)\n", \ - __FILE__, __LINE__, &(e), pud_val(e)) + pr_err("%s:%d: bad pud (%016lx)\n", \ + __FILE__, __LINE__, pud_val(e)) #if CONFIG_PGTABLE_LEVELS >= 5 #define p4d_ERROR(e) \ - pr_err("%s:%d: bad p4d %p(%016lx)\n", \ - __FILE__, __LINE__, &(e), p4d_val(e)) + pr_err("%s:%d: bad p4d (%016lx)\n", \ + __FILE__, __LINE__, p4d_val(e)) #endif #define pgd_ERROR(e) \ - pr_err("%s:%d: bad pgd %p(%016lx)\n", \ - __FILE__, __LINE__, &(e), pgd_val(e)) + pr_err("%s:%d: bad pgd (%016lx)\n", \ + __FILE__, __LINE__, pgd_val(e)) struct mm_struct;
This drops page table entry address output from all pxd_ERROR() definitions which now matches with other architectures. This also prevents build issues while transitioning into pxdp_get() based page table entry accesses. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- arch/x86/include/asm/pgtable-3level.h | 12 ++++++------ arch/x86/include/asm/pgtable_64.h | 20 ++++++++++---------- 2 files changed, 16 insertions(+), 16 deletions(-)